|
of the
FLORIDA STATE MUSEUM
Biological Sciences
Volume 22 1977 Number 2
GEOGRAPHIC VARIATION IN THE SONG
OF BELDING'S SAVANNAH SPARROW
(PASSERCULUS SANDWICHENSIS BELDINGI)
RICHARD ALAN BRADLEY
UNIVERSITY OF FLORIDA
GAINESVILLE
Numbers of the BULLETIN OF THE FLORIDA STATE MUSEUM, BIOLOGICAL SCIENCES,
are published at irregular intervals. Volumes contain about 300 pages and are not necessarily
completed in any one calendar year.
OLIVER L. AUSTIN, JR., Editor
RHODA J. RYBAK, Managing Editor
Consultants for this issue:
Luis F. BAPTISTA
JOHN WILLIAM HARDY
Communications concerning purchase or exchange of the publications and all manuscripts
should be addressed to: Managing Editor, Bulletin; Florida State Museum; University of Flor-
ida; Gainesville, Florida 32611.
Publication date: June 17, 1977
This public document was promulgated at an annual cost of $1,667.26 or
$1.667 per copy. It makes available to libraries, scholars, and all interested
persons the results of researches in the natural sciences, emphasizing the
circum-Caribbean region.
Price: $1.70
GEOGRAPHIC VARIATION IN THE SONG OF BELDING'S SAVANNAH
SPARROW (PASSERCULUS SANDWICHENSIS BELDINGI)
RICHARD ALAN BRADLEY'
SvNoPSis: The song of Belding's Savannah Sparrow, resident from Santa Barbara, California,
south to El Rosario, Baja California del Norte, was studied during the spring of 1973. Songs were
recorded from individuals at 14 of the 15 remaining breeding localities of this subspecies and
analyzed with an audiospectrograph. Recordings of color-banded birds indicated that each male
sang a single highly stereotyped song pattern. Detailed analysis of intrapopulational and inter-
populational variation was made. The study of interpopulational variation yielded a mosaic
pattern of song "dialects." The occurrence of such song dialects has been substantiated else-
where for a variety of species. The present study involves very small adjacent, but isolated pop-
ulations.
TABLE OF CONTENTS
INTRODUCTION ... .. .. .. ....... . . ... ......... ....... 58
ACKNOW LEDGEMENTS ...... ..... ........ .. .. .. ............ .. 59
M ET H O D S .... .. ........... ............ .. ..... ........ 59
R ecordings .. ... .. .. ......... .. ..... .... ...... 59
A n aly sis . .. ......... ... .. ............. . . .... 6 1
T erm in ology .. . ........ .. ............... .. ... ................... 6 1
R E SU L T S .. ... . ....... ... .......... . . . .............. .. .. .. ... . ... 6 1
C all R epertoire .. . .... .... ... ..... .. .. ... ... ... ... .. 61
Features of Song Delivery . .... .......... 65
The Structure of the Primary Song ...... ........ .. .. .. ... ........ 67
Ontogeny of the Song . ................. 68
Ind ivid ual V ariation ......... ... .. .. .......... .. . .. ............................... .. .. 69
Intrapopulational V ariation .. ............. .. .. ........................... 72
Interpopulational V ariation .. .. ............ .. ......... ......................... 76
Summary of Interpopulational Variation by Location ..... .. ..... ....................... 88
D isc U SSIO N ... . ... ... . ........ .... ... . . .. .. .. .. 94
L ITERATURE C ITED ..... .... .. ........ .. ............... ... .. . ... .. ........ 97
' The author is an Associate in Natural Sciences at the Florida State Museum, University of Florida, Gainesville 32611. This
paper was submitted in partial fulfillment for the degree of Master of Arts at California State University, Long Beach 90804.
Manuscript accepted 18 December 1975.
BRADLEY, RICHARD ALAN. 1977. Geographic variation in the song of Belding's Savannah Sparrow
(Passerculus sandwichensis beldingi). Bull. Florida State Mus., Biol. Sci. 22(2):57-100.
BULLETIN FLORIDA STATE MUSEUM
INTRODUCTION
Geographic variation in bird song has been the subject of recent studies
and has taken several forms. The early emphasis was on documentation of
variation within species having wide distributions. More recently compre-
hensive studies have been conducted using recordings from many localities
or analyzing variation between local contiguous or isolated populations. Per-
haps the best summary of the work on geographic variation in bird song is by
Thielcke (1969).
Early work on the Chaffinch (Fringilla coelebs) and other species revealed
a distinctive mosaic pattern of variation (Thielcke 1969). Song patterns used
by most of the birds in one place are similar to their neighbors' songs, while
individuals from other populations have different themes. Often an entire
system of such variants is found when several different populations are
studied. The term "song dialect" refers to this type of variation. Many authors
discussed the evolutionary significance of song dialects. Mayr (1963) stated
that geographic variation of song is a widespread isolating mechanism in
birds. Other workers expressed similar ideas about song as an isolating mech-
anism (Thorpe 1961, Marler and Tamura 1964, Lanyon 1969, Nottebohm
1969, Thielcke 1969, Armstrong 1973).
Nottebohm (1972) summarized the proposed mechanisms of such isola-
tion:
"It is necessary to assume that female birds develop a pref-
erence for the song dialect of the area where they are born, and
that this preference is revealed in their choice of partner. Males
in turn must learn to sing the dialect of their birth area. If birds
of both sexes migrate or wander between fledgling age and their
first breeding season, they must return to breed in the same gen-
eral area where they were raised. In this fashion an assortative
mating system based on song preferences reinforces a more or
less loose philopatry."
The Savannah Sparrow (Passerculus sandwichensis) is one of the most
widely distributed of North American sparrows. The species breeds from
71N (Barrow, Alaska) south to 16N (Hacienda Chancol, Guatemala) and
is divided into 18 subspecies that vary considerably in size, proportions, and
coloration (American Ornithologists' Union Check-list 1957, supplement
1973). Of the 18 subspecies 8 are restricted to the coastal marshes of California
and northwestern Mexico. Van Rossem (1947) presented an excellent review
of the seven races that breed in western Mexico.
The Savannah Sparrow form that breeds along the coast from Santa Bar-
bara south to El Rosario was originally named as a full species, Passerculus
beldingi, by Ridgway (1885). This race, now known as Passerculus sand-
Vol. 22, No. 2
BRADLEY: BELDING'S SAVANNAH SPARROW
wichensis beldingi (American Ornithologists' Union Check-list 1957) is re-
ferred to here as Belding's Sparrow. The name Savannah Sparrow is used
when referring to the species in general.
Belding's Sparrow is restricted to the tidal salt marshes of southern Cali-
fornia and northwestern Baja California. In a preliminary census conducted
in conjunction with this study, I estimated a population of fewer than 3,000
singing males (Bradley 1973). The restriction of this subspecies to local
patches of salt marsh has produced small isolated populations ideal for the
study of geographic variation. The pattern of song variation within the spe-
cies, as outlined by Borror (1961a) is well suited to the development of song
dialects: (1) each bird sings only one song pattern, (2) variation occurs between
different individuals, and (3) song patterns used in any particular location
show considerable overlap.
Because of restrictions of distance and time, recordings could be made of
only a limited number of populations. As a result, a somewhat arbitrary de-
cision was made to restrict the study to the coastal populations now assigned
to P. s. beldingi. Recordings from another coastal subspecies (P. s. alaudinus)
in central and northern California indicate a continuum of similar patterns
of variation in that subspecies, and perhaps throughout the species. This study
was conducted primarily in the spring of 1973, although some additional ob-
servations and recordings were made later in 1973 and early in 1974. Tape
recordings were made of 280 different individuals at 14 of the 15 known re-
maining breeding sites of Belding's Sparrow. No recordings were made at
Ensenada Bay, Baja California del Norte, because of time limitations and the
small, widely-scattered nature of that population.
AC KNOWLEDGEMENTS
I thank David R. Bontrager, Marjorie J. Bradley, John William Hardy, and Graeyer Mans-
field-Jones for reading all or parts of the manuscript and making many helpful suggestions. I
give special thanks to Charles T. Collins and Stuart L. Warter for guiding my research as well
as suggesting corrections and improvements of this paper. In addition to the above named per-
sons, many others helped me in the field, or obtained permission for my studies in restricted areas.
For such help I express my appreciation to Commander Robert Baker, Frank DeVore, L. E.
Fellows, Barbara Massey, Larry Pomeroy, Jerie St. Germain, Deane Swickard, Margaret Tay-
lor, and Bruce Wales. I also thank David Bradley for preparation of Figure 16, assistance in the
field, and innumerable hours spent conducting computer analysis of the data.
METHODS
RECORDINGS
Most of the recordings in this study were made with a Uher 4000 Report S tape recorder and
a Uher M 512 microphone mounted on either a 61 cm or a 76 cm fiberglass parabolic reflector.
Some additional recordings were made with a Sony TC 800 recorder and a Sony ECM 19 B mi-
crophone mounted on the 61 cm reflector. All recordings were made at a tape speed of 19 cm/s.
Recordings were made in the field with a hand-held reflector during the peak period of song
activity in the morning. Copies of the recordings are on file in the Bioacoustic Archive of the
Florida State Museum, Gainesville.
BULLETIN FLORIDA STATE MUSEUM
Belding's Sparrow is a bird of the coastal salt marshes of southern California and is largely
restricted to Salicornia-covered tidal flats. Each singing individual, presumed to be a male, de-
fends an exclusive territory in this habitat and regularly sings from one or more exposed perches
within his territory.
When I surveyed a particular location, I made recordings beginning with an individual at one
edge of the marsh and continued in a regular pattern from territory to territory until the entire
nesting area had been traversed. Usually I recorded 5 to 10 songs from each individual. As males
of this subspecies defend very small territories (Bradley 1973), each singing bird could be iden-
tified by its song perch location.
Great care was taken to record songs from distinct individuals. In those cases where a large
number of birds were singing from a relatively small area, only a few individuals were recorded
if any probability of confusion existed. With this method only small samples could be obtained
from some sites, but these samples are free from duplication. At some locations the samples were
recorded on two or more dates. In each case additional recordings for the sample were made in
parts of the marsh where birds had not been previously recorded. A list of locations visited and
sample sizes obtained is presented in Table 1. Information on the approximate population size
at each location is presented elsewhere (Bradley 1973).
TABLE 1.-LOCATION DATA.
Sample Letter
Number Location and City Size Code
01 Goleta Slough, Santa Barbara 7 GS
02 El Estero, Carpinteria 28 EE
03 Mugu Lagoon, Point Mugu 28 PM
04 Playa del Rey, Los Angeles 4 PR
05 Anaheim Bay, Seal Beach 61 AB
06 Huntington Harbour 5 HH
07 Bolsa Chica Lagoon, Orange County 0 BC
08 Upper Newport Bay, Newport Beach 30 NB
09 Santa Margarita Lagoon, Oceanside 29 SM
10 Agua Hedionda Lagoon, Carlsbad 10 AH
11 San Elijo Lagoon, Cardiff 4 SE
12 Los Penasquitos Estuary, Del Mar 21 LP
13 Imperial Beach, Imperial Beach 8 IB
14 Ensenada Bay, Ensenada 0 EB
15 San Quintin Bay, San Quintin 34 SQ
16 Laguna El Rosario, El Rosario 11 ER
Playback of recorded song was successful in eliciting close approach and song in several in-
dividuals tested at Anaheim Bay. Although the song of each individual proved to be constant, no
playback was used during the sampling portion of this study to avoid any possible influence on
the songs to be recorded.
To determine the amount of individual variation in song, and to verify information about the
territoriality of males of this form, a number of individuals were color-banded. Birds were cap-
tured in mist nets set across the surface of the marsh in the evening. In addition to a Fish and
Wildlife Service numbered aluminum band, three colored plastic bands were used on each bird
to produce individually recognizable combinations. Songs of some additional known, but not
color-banded individuals were recorded in the study period. These unbanded individuals were
chosen because they occupied solitary or readily identifiable territories where they could be
found repeatedly. All work on individual variation was carried out at the main study location
at Anaheim Bay. This site was relatively free from outside interference.
Vol. 22, No. 2
1977
BRADLEY: BELDING'S SAVANNAH SPARROW
ANALYSIS
One or more songs of each individual recorded were analyzed on a Kay Elemetrics Corp.
Sona-Graph, model 7029 A, employing the 160-16, 000 Hz scale, HS (high-shape) equalization,
and narrow band filter. Each audiospectrogram was then analyzed in detail. Each song was
transcribed into an alphabetic sequence and every distinguishable note given a paired code of
two letters. A total of 86 distinct note types were named from recordings made during this
study (Figs. 1 and 2). The first letter of the paired code (upper case) designates the general note
type (e.g. B notes are usually high-pitched introductory notes). The second letter (lower case)
indicates the specific variant of that particular note type. When one note is repeated two to
several times in sequence, a number follows the two-letter code indicating the number of repe-
titions (e.g. the note Ca repeated three times would be coded as Ca3). A complex string of letters
and numbers is then constructed as a representation of the specific song pattern of an individual.
For example, the song pictured in Figure 3 would be coded as AaBb4PaDaDbDcKaFdFeJa. In
a few cases a phrase (composed of many similar notes or syllables) was named with only one pair
of letters. Sequences so named are rapidly modulated buzzes or buzz phrases. It would be diffi-
cult to count each modulation in a buzz, and I believe that enumerating each as a separate note
would be meaningless. Differences in the rate of modulation and tonal quality of the buzz phrases
are indicated by the different lettered codes assigned to them.
Recordings of the songs from several known individuals were analyzed for diurnal and sea-
sonal variation. Finally, comparisons were made of inter- and intrapopulational variation in the
songs.
TERMINOLOGY
The nomenclature of bird song is nearly as variable as the number of studies conducted. In
this paper I have tried to use universally recognizable terminology, although in some cases it
may differ considerably from some other published works.
SONG.-The term song is here applied to the basic species-specific or "primary" song as dis-
tinguished from the other call notes of a species.
SoNG BouT.-A series of songs given in sequence at a more or less regular rate, ending with
a much longer pause or with the cessation of song.
NOTE.-A note has been almost universally defined as the smallest unit of bird song. It is rep-
resented on an audiospectrogram as a continuous trace. Schwartz (1972) gave a similar defini-
tion for the term "figure."
PHRASE.-A group of notes that combine to form a recognizable unit is termed a phrase (the
"note complex" of some authors). The individual notes that combine to form a phrase were
termed syllables by Marler and Tamura (1962).
Buzz.-A phrase made up of many similar notes uttered in rapid succession is a buzz. Borror
(1965) used the term buzz for sounds consisting of notes repeated at a rate greater than 40 per
second, or a single note that fluctuates at this rate. It should be noted that audiospectrograph
analysis yields little information about the nature of the modulation in a buzz. It is nearly im-
possible to tell if a sound is frequency or amplitude modulated (Greenewalt 1968). For an accu-
rate determination of the nature of the modulation within a buzz or other complex note, one
should use an oscilloscope as Greenewalt (1968) demonstrated.
SONG PATTERN.-The particular sequence of notes and phrases that comprise the song of an
individual is considered as one song pattern (equals "song type" or "theme" of other authors).
In some cases several individuals may sing songs of the same song pattern.
RESULTS
CALL REPERTOIRE
In addition to the primary song of the species, the chief subject of this
study, the Savannah Sparrow has a number of other typical vocalizations.
Gobiel (1970) described the various calls in this species' repertoire. I heard
As Ob Sc Be Of Bg Sh Si Bk BI SM Sn Ca CbCd Co
CfC9Cgh CiCQCk CIDa DbDc Di DiEa Eb Ec FsFb FcFd FeFf Go GGb Gc >
I I II I I I I II I
7 --T
IN.I -
--t 2(-
it Ah
A A A An Jn Ka (short) Ka oNg)W Kb La
-T- 10
I
Jb Jc A Je
BRADLEY: BELDING'S SAVANNAH SPARROW
and recorded many of the same call notes he described, as well as a few addi-
tional ones.
Dwight (in Chapman 1896) described the typical call note of the species
as a vigorous "chipping." Gobiel referred to this note as a softer version of the
"tsip" alarm note. Spectrograms of the typical call note recorded in the pres-
ent study are presented in Figure 2. This note ranges in frequency from 8.5 to
10 kHz and is rather weak with a duration of less than 0.05 seconds. Both sexes
uttered this "chip" note in a variety of contexts.
A slight variant of the typical call note described above was also recorded.
This variant was associated with copulation. Although I have heard both sexes
using this copulatory note, it is more frequently uttered by the female. The
structure of the copulatory note is illustrated in Figure 2. The frequency and
temporal characteristics of this note are quite similar to those of the typical
call note. The copulatory note is given just prior to copulation and is repeated
in rapid succession with intervals of less than 0.5 seconds.
The alarm note of the species is much louder and harsher than the typical
call note. Gobiel described the alarm note as "tsup" or "tsip." A spectrogram
of this note is included in Figure 2. The frequency range of the alarm note (7
to 11 kHz) is much greater than that of the typical call note and is consider-
ably louder. The time interval between successive alarm notes depends upon
the emotional state of the calling bird. In general the rendition increases in
rate, intensity, and volume as an intruder moves deeper into the nesting terri-
tory. The functions of the alarm note are to warn other sparrows of impending
danger and probably to distract a potential predator from the nest or young.
The intraspecific agonistic note is actually a loud buzz, which Gobiel
termed the hostile note. Both wide and narrow band spectrograms of this buzz
are presented in Figure 2. The hostile buzz is usually uttered twice in close
succession. Gobiel described the resultant sound as "psst-psst" or "buzt-buzt."
When delivered on the ground this buzz is usually accompanied by stereo-
typed posturing. The calling bird crouches down with its tail slightly cocked
and the wings lowered and fluttering out to the sides. On a few occasions I
saw actual attacks made by two adjacent territorial males that were display-
ing and buzzing to each other. In addition this buzz is frequently given dur-
ing an aerial chase.
The last and most complex call is presented in Figure 2. I have termed this
vocalization the flight slur; it is actually a complex sequence of notes lasting
FIGURE 1.-Spectrograms of the different note types. Each of the note types from Aa to La are
illustrated here in alphabetical order. A few of the combinations that might be expected (Bd,
Bj, Cc, etc.) were not present and have either been superseded by new naming schemes or proved
indistinguishable from existing note types. Two examples of the Ka buzz are included to demon-
strate the continuous variability in the length of this phrase. In all figures frequency is plotted
on the ordinate in kHz. In Figures 1 and 2 time is plotted on the abscissa in 0.2 seconds, in Figures
3 through 15 in seconds.
Ma Na Oa___ "k O a Pb PO
.- S ~illu.m/H sslmlts &tl "1""*w ^ at." l:11 &f Siilil ''- f ta
Ma Na Oa Ob Oc Od Pa Pb PC Pd Pe Pf Qa Ra Sa
I I I III I llI I II I
16 B
12-
8-Z
4- -
16 C
*12
a Zb . . a b c d e f g
1 1 1 1 1 1 1 lo m i
I I I I I I I I I I I I I I
16- D
12-
8 ........ 1 00 1,
4 ltiid I -E -,,-,,,-- B 5
I I I I I I I I I I 1 I I I
121
,NO*
t k
k a m
BRADLEY: BELDING'S SAVANNAH SPARROW
about 3.2 seconds. Although I noted this sound given most frequently at the
end of an airborne chase sequence, occasionally it is given from within the
vegetation (Barbara Massey, pers. comm.). The flight slur may be analagous to
the "flight song" described by Gobiel, who stated that the flight song was used
in communication between two members of a mated pair. I am not certain of
the function of the flight slur, but I believe it is associated with aggression.
FEATURES OF SONG DELIVERY
To me, the delivery of the Savannah Sparrow's primary song is perfunc-
tory, almost seeming mechanical at times. The singer usually perches in an
upright stance with the head held slightly back and utters the song with the
bill wide open. The song of Belding's Sparrow is usually given while the bird
is perched atop a sprig of Salicornia. I have also seen birds singing from higher
perches, such as the tip of small mounds of soil, fence posts, and other wooden
structures, as well as an occasional utility line. In addition to these typical
singing perches I have several times seen birds singing from open mudflats.
During intense territorial disputes males even uttered the primary song in
flight.
Although several authors have written of the male's song there is little
direct evidence that only the male is capable of song. I made observations on
10 individuals that I caught and color-banded. Of these 10 birds, 6 were known
to be males (cloacal protuberances present), 1 was a known female (brood
patch present), and 4 were not sexable. In the term of this study, I saw the
known female only twice after banding. She did not sing, but she did utter
the typical call note of the species. Of the six color-banded males only four
were seen subsequently, and all four sang regularly.
In addition to these observations of color-banded individuals, twice I saw
mating. Both times the male engaged in song bouts before and after the copu-
latory act. The female was silent except for the copulatory note.
Additional studies of more color-banded individuals need to be under-
taken, but considering closely related species (Bent 1968) and the observations
made in this study, song is most probably limited to the male. Herein singing
birds are assumed to be males.
The singing rate (number of songs per minute) varies with the time of day,
season, and the emotional state of the singing bird. This rate usually ranges
FI.;cHE 2.-Spectrograins of the different note types and calls. Line A and the first portion of B
represent a continuation of the list of note types from Ma through Zb. The last part of B illus-
trates the typical call notes of the species: a-alarm note, b-agonistic buzz (narrow band), c-
agonistic buzz (wide band), d through f-typical call notes (three repetitions), and g-precopu-
latory note. Line C is the flight slur. Line D shows different buzz phrases, first a narrow band,
then a wide band spectrogram of the same buzz. The phrase pairs in sequence are Pa, Pf, Pb,
Ka, and Ma buzzes.
BULLETIN FLORIDA STATE MUSEUM
part part part part
16 A
12
8 4 16,
16- B
12-
a4- *i" -- v-
0.5 1.0 1.5 2.0 2.5 3.0
FIGURE 3.-The four parts of a song. A is a narrow band spectrogram of bird song number 05-50,
B a wide band spectrogram of the same song.
from six to eight songs per minute. Singing may begin just before sunrise, but
the peak of song occurs most often between 30 and 90 minutes after sunrise.
In general, song activity decreases throughout the day with a lull during the
midday hours. Song activity makes a secondary peak in the evening and may
continue until well after dark. For example, on 27 March 1973 the evening
song peak was at 1830 (about 20 minutes after sunset) and singing continued
until about 1900. I heard sporadic songs as late as 2200. King (1972) also re-
ported hearing night song from the Rufous-collared Sparrow (Zonotrichia
capensis).
In addition to diurnal variation, the rate of singing changes with the sea-
son. I first heard song at the main study area (Anaheim Bay) on 26 January,
when a few males were singing sporadically. On 2 February there was con-
siderably more song activity, and I saw several territorial chases. The height
of singing in 1973 lasted from mid-February through mid-May. Song activity
was noticeably lower in late May and dropped off rather quickly in June. By
the end of July adult song activity was very low, but I began to hear subsong
from birds of the year. In late August subsong activity was high, and only oc-
casional adult songs were heard. The following winter (1973-1974) song ac-
tivity began earlier in the year. By 24 December adult song was heard occa-
sionally, and it was noticeably more regular on 9 January (Barbara Massey,
pers. comm.).
The rate of singing can be increased artificially by recording an individ-
ual's song and then playing it back through a loudspeaker. With this technique
I could increase the rate of song to approximately 12 songs per minute. That
one individual rarely sings alone is interesting to note. The song of one bird
tends to stimulate all of his territorial neighbors, which frequently transforms
relative silence into a peak of song activity by a chain reaction of singing and
countersinging.
Vol. 22, No. 2
BRADLEY: BELDING'S SAVANNAH SPARROW
THE STRUCTURE OF THE PRIMARY SONG
The primary song of the Savannah Sparrow is a rather unmusical series of
thin high-pitched chips and buzzes. One of the most accurate general descrip-
tions of the song of the Savannah Sparrow is given by Borror (1961b). Al-
though the Belding's Sparrow songs recorded in this study have qualities simi-
lar to those Borror described, several differences are apparent.
The high pitched and rather weak nature of the primary song of the Sa-
vannah Sparrow may be related to the territory size and habitat preferences
of the species. As I have already mentioned, males of this species command
very small territories. Pairs nest primarily in open grassland or marshland
habitats. As distances between neighbors are quite small with little or sparse
intervening vegetation, no necessity exists for a louder or lower pitched song
that would carry farther. In fact, the weak nature of the song may well render
the singing males less conspicuous to predators. The characteristics of Savan-
nah Sparrow song conform well to the theory, discussed by Emlen (1971a),
Jilka and Leisler (1974), and Morton (1975), relating the quality of a species'
song to its habitat.
The songs of individuals recorded in this study ranged in length from 1.7 to
3.1 seconds, and most songs were between 2.0 and 2.5 seconds long. The notes
range in frequency from 2 to 12 or 13 kHz (certain harmonics may reach
16 kHz or higher). Most of the sound energy is concentrated between 4 and
11 kHz.
The structure of the primary song is best described by treating it in four
sections (Fig. 3). The first section (Part I) is composed of three to eight similar
notes. These introductory notes average higher in pitch than the remainder
of the song. Most are named as variants of note B (Fig. 1 and 2). As the spectro-
grams of notes Bb through Bn show, the structure of the note includes a hori-
zontal portion and a vertical portion. The horizontal portion represents a con-
tinuous tone of one frequency and the vertical portion a sharp staccato ending.
This ending makes the sound audible as a "chip." In contrast, a note that lacks
this sharp ending has a more melodious sound (like note Ja). In addition to the
introductory notes of type B, Part I often includes the very short and high-
pitched note Aa, which is quite similar to the typical call note of the species.
In fact a calling bird occasionally broke directly into song, incorporating the
last call note or two into the introductory phrase. I heard note Aa from nearly
every sparrow recorded, yet no bird included it consistently. Therefore, I have
assigned very little importance to the presence or absence of note Aa.
The second part of the primary song varies in composition. Among the
50 different note types that occur in Part II many are shorter than 0.1 seconds.
Individual birds include from 1 to 11 different note types. In some cases a par-
ticular note is repeated 2 to 17 times in sequence. Notes of the general types
C, D, and E are frequently found in Part II. In many cases these notes are ar-
BULLETIN FLORIDA STATE MUSEUM
ranged in a specific pattern that may recur in songs of several other members
of the same population. For example the sequence DaDbDc is common
among birds recorded at Anaheim Bay. In addition to these notes, individuals
often include a very short buzz in Part II. Buzzes found in Part II, unlike most
of the buzzes that compose Part III, are modulated approximately 50 to 100
times per second. The buzzes that occur in Part II are classified as P, S, and
Z phrases (Fig. 2).
The third part of the song is the main buzz section. It usually includes one
or two K-type buzzes or an L-type buzz. Buzzes occurring in Part III are much
more rapidly modulated than the type of buzz phrase found in Part II. The
rate of modulation is frequently as high as 180 times per second. On the nar-
row band spectrograms these buzzes appear as indistinct bands, ranging in fre-
quency from 5 to 10 kHz. With the wide band filter setting, spectrograms are
produced that appear as a series of vertical streaks (Fig. 1). In addition to the
buzz phrases in Part III, a few shorter notes are found occasionally between
two successive buzzes. Many of the note types found between buzzes are the
same as those found in Part II. Rarely a sequence of notes characteristic of
Part II will also lie between the two buzzes.
The final section of the primary song is the shortest of the four parts. This
"terminal flourish" is composed of one to five short high-pitched notes fol-
lowed by a single low-pitched note. The high-pitched notes are occasionally
complex in structure. In some cases they even appear to possess the dual-
source quality described by Greenewalt (1968). Examples of such complex
notes are classified as types F, I, and R. The final note is usually between 0.15
and 0.4 seconds in length and has a pure, almost whistled quality (note Ja,
Fig. 1). This tonal quality is attributable in part to the narrow frequency range
of the note (between 5 and 6 kHz). As will be shown later, Part IV is one of the
most consistent phrases found within the songs of a particular population. In
addition, most populations have one or more unique variants of this terminal
flourish.
ONTOGENY OF THE SONG
To my knowledge no study on the development of song in the Savannah
Sparrow has been conducted to date. A complete study, probably involving
Kaspar Hauser isolates, is needed before definitive conclusions about song
learning can be made, but the following observations may throw some light
on the process as it may occur in the wild.
I first heard subsongs, presumably given by birds of the year, on 28 August
1973 in the marsh at Anaheim Bay. A hatching-year individual can usually be
identified in the field by the grayish color of the superciliary line and loral
spot, which are yellowish in an adult. The plumage of the young bird appears
looser and the markings less distinct. Subsongs were delivered from the top of
Salicornia bushes in the same general manner as the definitive songs of adult
Vol. 22, No. 2
BRADLEY: BELDING'S SAVANNAH SPARROW
males. Young birds rarely throw back the head or open the bill and they ap-
pear to assume a more relaxed posture.
Subsong at first is a rather low volume series of buzzes and chips with little
organization. Another type of subsong, which presumably represents a later
stage of development, resembles the "random warbling" described for many
other oscines (Lanyon 1960). Even within this phase of song development
some typical call notes are still included. One of the call notes most frequently
heard was a buzz similar to the hostile buzz of adult Savannah Sparrows.
I term the third type of subsong "discrete subsong." This type of song was
heard more frequently late in the summer and in the fall. It consists of a
shortened "warbling" song about 2.5 to 3.0 seconds long, and contains some
notes reminiscent of definitive primary song..In Lanyon's (1960) scheme, this
phase is probably "rehearsed song." Unfortunately I was unable to visit the
study area throughout much of the fall and winter, but young birds continued
to sing subsong well into December (Barbara Massey, pers. comm.). In the
peak season of subsong (late summer and fall) few adults were heard, and the
primary song of adult males was sporadic and irregular. Structure of adult
primary song heard at this time was typical of birds recorded in the spring.
Although Mulligan (1966) found that song development in Song Sparrows
(Melospiza melodia) was essentially innate, studies of other fringillids indicate
that young birds must learn their songs from adults. Chaffinches for example
produce abnormal songs when reared in isolation (Poulsen 1951, Thorpe
1958). In similar studies summarized by Marler (1967), normal song develop-
ment in members of the genera Junco and Zonotrichia was also dependent
upon previous auditory experience. The role of learning and other aspects of
the ontogeny of the song in Savannah Sparrows remains to be worked out.
INDIVIDUAL VARIATION
The song of each Belding's Sparrow is remarkably stereotyped. A typical
song bout involves 15 to 20 droning repetitions of a particular song pattern. A
short pause is followed by another monotonous song bout. With occasional
pauses for feeding and maintenance activities, this pattern may last an entire
morning during the seasonal peak of song activity. In fact, aside from minor
omissions at the beginning or ending, the song pattern of each known bird re-
corded remained constant throughout this study.
As an example of this constancy, I have included spectrograms of bird
05-58 in Figure 4. As shown, the song pattern (AaBb3Ce3HiDaDbDcKaFd-
Feja) is the same in all this bird's songs. These recordings were made during
the period 14 February-21 April. Variation seen in recordings of this individu-
al's song includes the occasional omission of an Aa, Bb, or Ce note, as well as
the length of the buzz phrase. One color-banded male (XR-RR), first recorded
on 2 April 1973, was recorded singing the same song pattern 10 February
1974. Although this is the only bird I was able to record in both nesting seasons
AU' -MO P
N^L -- W w
. 4*
A. ~ R0S -' ~ii*'b ~
0.5
1.5
2.0
2.5 3.0
FIG'RE 4.-Four spectrograms of bird 05-58. Note variation in the presence of the first introductory note Aa as well as in the number of Bb notes.
This bird was one of the few that varied the number of a note in Part II (the note Ce is repeated three times in A, C, and D but only twice in B).
A and B were recorded 14 February, C on 17 February, and D on 26 February 1973.
BRADLEY: BELDING'S SAVANNAH SPARROW
(1973 and 1974), I believe it probable that the song of most, if not all individ-
uals is constant from year to year.
The chief variant within an individual's song is the omission of one or more
A- or B-type introductory notes. A few birds varied the number of repetitions
of other notes within their songs. For example, birds 05-26 and 05-58 at Ana-
heim Bay used either two or three C notes. In a few instances an individual
cut his song short; each of these cases could be accounted for by outside dis-
turbance. A bird that was in the middle of a song occasionally stopped to pur-
sue an interloper in his territory. A few times I inadvertently made a sudden
movement or sound that triggered an immediate cessation of song.
Although not all birds treated here as known individuals were color-
banded, each was an occupant of a particular territory. Of the birds that were
not color-banded, only individuals with fairly isolated territories could be fol-
lowed throughout the season, such as bird 05-58 who defended a small terri-
tory along the edge of the marsh at Anaheim Bay just north of the marine
laboratory trailer of California State University at Long Beach, and had no im-
mediate territorial neighbors. This individual was easily located on each visit.
Many of the known individuals could not be located later in the season for
additional recordings. One of the reasons for losing track of these birds in May
and June was that a turnover in territorial males occurred after the first brood
fledged. Apparently some males gave up their territories or moved to other
territories after the first nesting. Others, possibly younger males, took their
places and the cycle of nesting activity continued well into the summer.
In many bird species the repertoire of an individual is quite varied. Borror
(1956) told of a Carolina Wren (Thryothorus ludovicianus) singing 22 different
songs. In fact examples of species in which one individual sings a variety of
song patterns can be found in many higher passerine families. Within the
Fringillidae up to 24 different song patterns have been recorded from indi-
vidual Song Sparrows (Nice 1943). Borror (1961a) listed 37 variants for an in-
dividual Bachman's Sparrow (Aimophila aestivalis) and 58 for a Lark Sparrow
(Chondestes grammacus). In other members of the family the repertoire is not
so varied. Songs of the Yellowhammer (Emberiza citrinella) and the Chaffinch
follow a pattern, but each male has several slightly different themes (Thielcke
1969).
Belding's Sparrow is by no means unusual in having a restricted repertoire.
The songs of male White-crowned Sparrows (Zonotrichia leucophrys), White-
throated Sparrows (Zonotrichia albicollis), and Rufous-collared Sparrows are
usually constant (Baptista 1974, DeWolfe et al. 1974, Marler and Tamura
1962, Nottebohm 1969), as are those of the Ortolan Bunting (Emberiza hortu-
lana Conrads and Conrads 1971). Although there were a few exceptions,
Thompson (1970) reported that most male Indigo Buntings (Passerina cyanea)
sing but one song pattern. I know of no explanation for the variation in reper-
toire size of the various species that have been studied.
BULLETIN FLORIDA STATE MUSEUM
INTRAPOPULATIONAL VARIATION
Although the song of each individual Belding's Sparrow is nearly constant,
the different birds in each population show considerable variation. A series of
distinct song patterns were named from each recording locality. In fact the
number of different patterns is usually slightly less than half of the sample size
(Table 2). These song patterns do not occur with random frequency, and sev-
eral song patterns are dominant. When individuals were sorted by song pat-
tern, I found that nearly 50% of birds from a given sample sang one of the
three dominant song patterns for that population (Table 2). In two marshes a
single song type represented a large proportion of the sample. At Anaheim
Bay 18 of the 60 individuals sampled used song pattern AB-01, and at El Estero
14 of the 28 birds recorded sang the pattern EE-02. At the other locations
where relatively large samples were taken several song patterns were domi-
nant.
TABLE 2.-FREQUENCY OF THE DOMINANT SONG PATTERNS.
Number
Number Singing % Singing
of Song Sample Dominant Dominant
Location Patterns Size 3 Themes 3 Themes
El Estero 8 30 21 70
Point Mugu 17 28 10 30
Anaheim Bay 23 61 32 52
Newport Bay 12 30 17 57
Santa Margarita 13 29 12 40
Los Penasquitos 13 21 10 48
San Quintin 15 34 14 41
Total 101 232 115 49.6
'This table includes only the larger populations, as analysis of populations with fewer than 20 individuals in the sample would
be unproductive.
The spatial distribution of the different song patterns within a particular
population was not studied in detail, but I did note that individuals with the
same song patterns were somewhat clustered. In neighboring territories I fre-
quently recorded four or five individuals with nearly identical songs. Although
I was unable to plot the territories of individuals accurately, clustering can
be demonstrated qualitatively by analysis of the San Quintin data recorded at
two locations approximately 2 miles apart on opposite sides of this rather wide
bay. Although the Salicornia marsh habitat is nearly continuous around the
bay, there is probably little interchange between the two sites during the nest-
ing season. When the songs of birds from these two areas were compared, I
Vol. 22, No. 2
16- A 5
- -
16- B
12-
a-C
16- D
12-
J-----^-----^----------,-------------- -- -
a--
16- D
12-
8- '^^ S f ^ ^ -- f
0.5 1.0 1.5 2.0 2.5 3.0
FIGURE 5.-Spectrograms recorded at Coleta Slough and Playa del Rey. A-song pattern GS-01, B-pattern GS-02, C-pattern PR-01, D-pat- -
tern PR-02.
BULLETIN FLORIDA STATE MUSEUM
found that only one song pattern was common to both sides of the bay. This
song pattern (SQ-04) was recorded from four individuals on the east side of
the bay. In addition, five song patterns were unique to the west side of the
bay and nine were unique to the east side.
Clusters of similarly singing individuals were also noted in populations of
Rufous-collared Sparrows (Nottebohm 1969) and Indigo Buntings (Passerina
cyanea) (Thompson 1970). One possible explanation for the origin of cluster-
ing (supported by Thompson) is that first year birds learn their songs as they
settle down on new territories in the spring. In this case they might tend to
learn by imitation from their immediate neighbors. Kroodsma (1974) demon-
strated that learning from neighbors occurs in Bewick's Wrens (Thryomanes
bewickii). This theory implies that young males would undergo the transition
from subsong to full song during the early spring. This is unlikely to occur in
Savannah Sparrows as I noted no subsong activity during this period. In fact,
on the first day songs were heard (28 January) the patterns were identical to
those recorded later during the peak of song activity. Subsong was heard and
recorded only in the late summer and fall.
The possibility that young birds learn their songs in the late summer from
one adult, leave in winter, and then return to that specific area to form clusters
seems equally remote. In contrast to other forms of the Savannah Sparrow,
Belding's Sparrow is thought to be resident in the Salicornia marshes of coastal
southern California and northern Baja California. Although Savannah Spar-
rows appear in flocks during the winter, it is possible that some degree of
homesite tenacity restricts movement from one part of the marsh to another.
Such site tenacity would explain the general tendency for birds on one side of
San Quintin Bay to sing entirely different patterns from birds on the opposite
side. Possibly those song patterns found in common were carried by an indi-
vidual or individuals that strayed across the bay during the winter. The reso-
lution of this question must await further study with color-banded individuals
that can be followed from year to year.
A detailed analysis of intrapopulational variation was conducted at the
main study area, Anaheim Bay. The sample obtained at Anaheim Bay con-
tained 61 individuals, representing about half the estimated population of
singing birds. Between 75 and 80% of the males nesting in northern and east-
ern portions of this marsh were recorded and yielded a total of 23 song pat-
terns. As mentioned earlier, 18 individuals sang identical versions of the domi-
nant song pattern AB-01. Table 1 lists the song patterns recorded at each lo-
cality and the number of individuals that sang each pattern.
Although each song pattern has a unique sequence of note types, several
notes and phrases are common to most of the songs from one population. For
example the introductory notes Aa and Bb were represented in each song pat-
Vol. 22, No. 2
16- A
S12-
I I I I
12-
a-
16- C
12- >
16- D
12- ..
0
8- 4 4 4 o
4-
I I I I I I
0.5 1.0 1.5 2.0 2.5 3.0
FIGURE 6.-Spectrograms recorded at El Estero. A-pattern EE-01, B-pattern EE-02, C-pattern EE-01, and D-pattern EE-06.
BULLETIN FLORIDA STATE MUSEUM
tern from Anaheim Bay. The phrases DaDbDc (from Part II) and FdFeJa
(from the terminal flourish) were found in most of the song patterns. The oc-
currence of each note was tabulated for the 280 individuals recorded in this
study. Of the 85 note types named herein, 35 were used at Anaheim Bay.
The only introductory notes recorded at Anaheim Bay were types Aa and
Bb. The number of Bb notes varied from one to four. Even within the songs of
an individual bird, the number of Bb's occasionally varied. Most variability
among different song patterns occurred in Part II of the songs. This portion
frequently included a short buzz of type P or a repeated series of similar notes
of type C, followed by a sequence of short high-pitched notes. All but 14 in-
dividuals (six song patterns) included the phrase DaDbDc in Part II.
Part III of most songs consisted of a single K-type buzz. One individual
sang an L-type buzz. None of the individuals in the Anaheim Bay sample used
more than one buzz in Part III. The terminal flourish consisted of three notes
in the phrase FdFeJa. Two individuals substituted a Jf for the Ja in their ter-
minal flourishes. I recorded only one bird (number 05-18) that did not use this
terminal flourish. This individual ended his song with the unusual sequence
DaDcDc and was also the only representative from Anaheim Bay to use an
L-type buzz.
Two other individuals sang unusual songs. Bird 05-49 sang a very long song
(up to 3.1 sec) beginning with an Aa note and a series of eight short notes and
two type P buzzes before using the two Bb introductory notes. These two Bb
notes were followed by the typical sequence PaDaDbDcKaFdFeJa. Another
odd song pattern was recorded for bird 05-20, which used four notes and a
type P buzz between the first Bb and the last two Bb's of its introduction. This
pattern had the same typical ending sequence as bird 05-49.
The extent of intrapopulational variation detected at the other locations is
comparable to that described for Anaheim Bay. Each site had a few dominant
song patterns, and the second portion of the song showed the most variability
within each population. Most individuals in each sample shared similar B vari-
ants and many. had a characteristic terminal flourish. Each of the larger
samples included one or two individuals with unusual songs.
INTERPOPULATIONAL VARIATION
Although the songs of different individuals within one population show
considerable variation, the different populations show even greater variation.
Variation within a population (intrapopulational) frequently takes the form
of a few different notes and phrases being substituted for the more common
patterns and sequences. As I showed earlier, the basic pattern usually remains
intact. Often most of the singing males share one or two dominant song pat-
terns. Most of the intrapopulational variation occurs within the middle por-
tion of the songs (Part II). Interpopulational variation, on the other hand, in-
volves changes in nearly every part of the song structures. Basic patterns are
Vol. 22, No. 2
N% ~--n
- .-.-----'-.
Orr. 0 waumw%0, *t
----I I
;>
z
0
nI
Cn
49 ago(- **-.^^ I .l .II. ^
&&,Low- ~ tH~l _
16- D
12-
8-
4-
I I I
0.5 1.0 1.5 2.0 2.5 3.0
FIGURE 7.-Spectrograms recorded at Point Mugu. A-pattern PM-01, B-pattern PM-03, C-pattern PM-06, and D-pattern PM-17.
BULLETIN FLORIDA STATE MUSEUM
different in each population, and in many cases there are also changes in the
structure of particular notes. Extensive variation between two populations
does not preclude the sharing of notes and even note sequences. Such overlap
is common, especially in adjacent localities, but of the 280 individuals ana-
lyzed in this study no two individuals from different populations shared the
same song pattern. For illustrations of the dominant song patterns from each
locality consult Figures 5-15.
VARIATION IN PART I.-Variation within the introduction involves both the
number and structure of the notes. The presence of note Aa is variable even
within the songs of one individual. Note Aa is the only note frequently omitted
in any individual's song. As recordings of most individuals involved only one
song bout on a particular date, there is no assurance that the presence or ab-
sence of note Aa from songs recorded is a constant characteristic of that indi-
vidual's song. The presence or absence of an Aa note in recordings of a particu-
lar song pattern is essentially a chance event, depending on the structure of
the specific songs recorded, and is thus of little if any significance.
Most introductory notes are of the general type B. All of the birds in the
sample, except four individuals recorded at Playa del Ray, included at least
one type B note. I named 11 different variants of type B notes (Fig. 1). All of
the variants share some general time and frequency characteristics. In most
cases a particular note variant is found in only one or two localities, usually
close together geographically. The specific type B note variants recorded at
each locality are shown in Figure 16. A listing of the approximate distances
between adjacent recording localities is presented in Table 3.
VARIATION IN PART II.-The middle portion of the song of Savannah Spar-
rows is the most complex and varied of all four sections. In the 280-bird
sample I recorded 50 different note types within Part II. As mentioned earlier,
most of the types in this section are rather short and high-pitched. In addition
to these notes, I found eight types of buzz phrases in Part II. In some songs a
number of type C variants were used in combination to produce a loosely
structured buzz or rattle. An extreme example of this is song pattern PM-17
(Table 4). In the songs of the three individuals that used this song pattern, the
note Cl was repeated 14 to 17 times. The result is an audible rattle (Fig. 7).
A more typical example occurred in many songs recorded at Anaheim Bay.
At this location many individuals sang two, three, or four repetitions of Ca,
Cb, Cd, or Ce notes. The result is a loose buzz quite similar in quality to a Pa
or Pb buzz (Figs. 3 and 8). Variation within Part II took many forms. The num-
ber, structure, and arrangement of the notes change as well as the particular
notes used. Any given population may also contain a number of regular pat-
terns or sequences of notes. Variation within some localities was quite exten-
sive, while others showed only a few different patterns. A similar situation
exists in White-crowned Sparrows (Orejuela and Morton 1975).
Vol. 22, No. 2
>1
fit-21
~z
16-D
12-
8-1
I I I I
0.5 1.0 1.5 2.0 2.5 3.0
FIGURE 8.-Spectrograms recorded at Anaheim Bay. A-pattern AB-01, B-pattern AB-02, C-pattern AB-03, and D-pattern AB-15.
% ---i
I
TABLE 3.-APPROXIMATE COASTLINE DISTANCES BETWEEN LOCALITIES (MILES).
Location Number
Location
Goleta Slough
El Estero
Point Mugu
Playa del Rey
Anaheim Bay
Huntington H.
Newport Bay
Santa Margarita
Agua Hedionda
San Elijo Lagoon
Los Penasquitos
Imperial Beach
San Quintin
El Rosario
01 02 03 04 05
06 08 09 10 11 12 13 15 16
----------------- -
20 X
59 39 X
102 82 43 X
134 114 75 32 X
(136) (116) (77) (34) (2) X
149 129 90 47 15 (14) X
188 168 129 86 54 (52) 39 X
195 175 136 93 61 (59) 46 7 X
205 185 146 103 71 (69) 56 17 10 X
211 191 152 109 77 (75) 62 23 16 6 X
235 215 176 133 101 (99) 86 47 40 30 24 X
415 395 356 313 281 (279) 266 227 220 210 204 180
450 430 391 348 316 (314) 301 262 255 245 239 215
'Locations 07 and 14 were omitted from this table because no recordings were obtained at these sites. Distances from Huntington Harbour are placed in parentheses to emphasize the fact that this <
locality is part of the same marsh complex as Anaheim Bay.
10
to
i-i
- -
__4_ __ -
--- --
--1
jtT
_~444 ___.
. .* *> q-* *'9 .
I ]I
0
16- D
12-
8-
4-
0.5 1.0 1.5 2.0 2.5 3.0
FIG(;UE 9.-Spectrograms recorded at Huntington Harbour and Agua Iledionda Lagoon. A-pattern HH-02, B-pattern AH-01, C-pattern All-
02, and D-pattern AH-04.
I .
. "'*""
BULLETIN FLORIDA STATE MUSEUM
TABLE 4.-SONG PATTERNS BY LOCATION.
Pattern Number
Number Lettered Code in Sample
Goleta Slough (N = 7)
GS-01 AaBg4 CaEaCaDa MaJdKb DiFgDiJb 4
GS-02 Aa2Bg4 CaEaCaDb LaJdKb DiFfDiJi 3
El Estero (N= 28)
EE-01 Bg7 CaDiCaDaCa2Ia Ka EaOcDiJb 2
EE-02 AaBg4 Ca4DiHb Ka EcOcDiJb 14
EE-03 Bg5 Ca4EcHb Ka IaEcOcDiJb 1
EE-04 AaBg4 Ca4DiJb KbIaKa DaOcDiJb 4
EE-05 (Aa)'Bg4 CaDaCaDaCaHb Ka EaOcDiJb 1
EE-06 AaBg4 PfDillb Ka EcOcDiJb 3
EE-07 Bg6 Ca6DiHb Ka IaDiJb 2
EE-08 Aa2Bg5 Ca4DaHb Ka laEaOcDiJb 1
Point Mugu (N = 28)
PM-01 AaBhBi2 La DaCaJI 2
PM-02 Aa2BhBi2 LaDaJcDaKb IbEaDc 1
PM-03 Aa2BhBi2 La EaCaDaJk 3
PM-04 Aa3BhBi2 CaEaOc Ka IbEaDcJb 1
PM-05 Aa2Bh4 Ca8 LaDaEaKa JcEaDc 1
PM-06 Aa2BhBi2 Cb2DcDa Ka IbEaDcJb 4
PM-07 Aa2BhBi Ca4DaCaDcJc Ka IbEaDcJb 1
PM-08 Aa2BhBi2 OcDaDb KaDaOc2Kb IbEaDc 1
PM-09 Aa2BhBi2 Ca2DaQaDcOc Ka IbEaDcJb 2
PM-10 Aa2BhBi2 OcKaDcJcEc Kb IbEaDcJb 1
PM-11 Aa2BhBi2 LaHbDaKa IbEaDcJi 1
PM-12 Aa2BhBi2 LaDcOcKb 1
PM-13 Aa2BhBi2 Oc2DcDa LaDcJcKb IbEaJb 2
PM-14 Aa2BhBi2 Ca2DaCaDcOb Ka IbEaDcJb 1
PM-15 Aa2BhBi2 Oc LaDcHeDaKa IbEaDcJb 2
PM-16 Aa2BhBi2 Ca3DaHe Ka IbEaDcJb 1
PM-17 Aa(3)BhBi2 CI(17)EaPePb Kb Jd 3
Playa del Rey (N = 4)
PR-01 Aa3DcEb3 PaHa Ka ObHcJh 2
PR-02 AaEaDbOcDcCaEb2 PaHa Ka OcOdJb 2
Anaheim Bay (N = 61)
AB-01 Aa(2)Bb(4) PaDaDbDc Ka FdFeJa 18
AB-02 AaBb(4) Cb2DaDbDcPbGa Ka FdFeJa(orJf) 3
AB-03 AaBb(4) Cd3ZbDaDbDc Ka FdFeJa 6
AB-04 AaBb(4) Cd3ZaDa Ka (FdFeJa) 2
AB-05 AaBb(3) Ca3Gb Kb FdFeJa 1
AB-06 AaBb(3) CaDaPcDaDbDc Ka FdFeJa 1
AB-07 AaBb(3) Ca3ZbDaDbDc Kb FdFeJa 2
AB-08 (Aa)Bb(3) Oc La DaDcOc 1
AB-09 AaJmDaPdHaCaEaDcPaEcCfBh2 PaDaDbDc
Ka FdFeJa 1
AB-10 (Aa)Bb3 Ca3ZaDaDbDc Ka FdFeJa 1
AB-11 (Aa)Bb3 OcPcDaDbDc Ka FdFeJa 1
AB-12 AaBb3 Ce4DbDc Ka FdFeJa 1
AB-13 (Aa)Bb4 Cd(3)DaHfDaDbDc Ka FdFeJa 2
AB-14 (Aa)Bb4 EbCaEcPcDaDbDc Ka FdFeJa 1
Vol. 22, No. 2
z --W-'-. ^, umoMm H --. ^
: ____________ *'. '-1
-~ ~ -~ -
* ~*
12
8 %a
0.5
2.0
2.5
2.5
FIGURE 10.-Spectrograms recorded at Newport Bay. A-pattern NB-04, B-pattern NB-07, C-pattern NB-09, and D-pattern NB-12.
3
3.0
BULLETIN FLORIDA STATE MUSEUM
TABLE 4 (CONTINUED).
Pattern Number
Number Lettered Code in Sample
AB-15 (Aa)Bb(4) Ca2Ga Ka FdFeJa 8
AB-16 (Aa)Bb(2) Ca2GbObDaDbDc Ka FdFeJa 2
AB-17 (Aa)Bb(4) CdPaDaDbDc Ka FdFeJa 1
AB-18 AaBb3 CbDaDbDc Ka FdFeJa 1
AB-19 AaBb(3) Ce31HiDaDbDc Ka FdFeJa 1
AB-20 AaBbEc2PcEcCfBb2 PaDaDbDc Ka FdFeJa 2
AB-21 AaBb4 PcDaHcDb Ka FdFeJa 1
AB-22 AaBb2 Ca3DaDbDc Ka FdFeJa 3
AB-23 AaBb3 Ce2DaDbDc Ka FdFeJa 1
Huntington Harbour (N = 5)
HH-01 AaBb3 Ca3DaDbEc Ka DcDgJa 1
HH-02 AaBb3 CeCaOaDcDb Ka FdFeJa 2
HH-03 AaBb3 Ce3ZbDbDc Ka FdFeJa 1
HH-04 AaBb4 Oc LaDcDbDcKa FdFeJa 1
Newport Bay (N = 30)
NB-01 Bc7 OaEa KbDaHaKa EaJb 1
NB-02 AaBc5 ChPaDaHcDa Ka FdDjJb 1
NB-04 Bc(6) ChPaDaHcEa Ka EaFaFdJa 7
NB-05 Aa2JdDcPbOcEc2CfBh CeEcHa Ka DcFaFdJa 2
NB-06 Bc4Bf2 PaDaHa Ka FaDaJa 1
NB-07 AaBc4Bf2 Ca2PdDa Ka EaFaFdJb 3
NB-08 Bc6Bf PaPdDa Ka EaFaFdJa 4
NB-09 Bc(3)Bf2 PaHd Ka EaFaFdJa 1
NB-10 Bc4Bf3 KaDbDaKbRa 1
NB-11 Bc5Bf2 Ca4HdDa Ka EaFaFdJa 1
NB-12 (Aa)Bc3 PbDiHa Ka EaFaDaJb 6
Santa Margarita (N = 29)
SM-01 AaBk3 Oc KaDaKb IcDaJa 5
SM-02 AaBk4 Ca20c KaDbDaKbDa Ja 2
SM-03 Aa3Bk3 Ca20c KaHfDaKb IcDaJa 4
SM-04 AaBk3 KaDa2Kb IcDaJa I
SM-05 Aa2Bk3 Oc KbDa2Kb IcDaJa 2
SM-06 AaBk3 Oc KaDc2Kb DcJa 1
SM-07 Aa2Bk3 Ca2DcHe KaDbDcKb Dcja 2
SM-08 AaBk3 CiHd KaHfDaKb IcDaJa 2
SM-09 Aa2Bk3 Oc LaHfDcKb IbDaJa 1
SM-10 (Aa)Bk3 Cb20c KaHfDaKb Daja 3
SM-11 Aa2Bk2 NaKbHcDaKb FcDcJa 3
SM-12 (Aa)Bk3 EcOc KaHfDaKb IcDaJa 2
SM-13 Aa2Bk2 Oc Kb IcDcJa 1
Agua Hedionda Lagoon (N = 10)
AH-01 Bh(3) Ca4He KaEaGcKb Daja 2
AH-02 BhBk3 Cj4Hh KaEaGcKb EcJa 2
AH-03 AaJcBh4 Oc KaSaEaGcKb EcJa I
AH-04 AaBh(3) Ca40c KaEcGcKb EcJa 3
AH-05 Bh(3) Ca30c KaEcGc Ecja 1
AH-06 AaBh3 PaOc KaDaGdKb Daje 1
San Elijo Lagoon (N = 4)
SE-01 (Aa)Bk3 KbDcOcKbPbDaKb DaJa 2
SE-02 (Aa)Bk3 KbOcKbPdEcKb EcJa 1
Vol. 22, No. 2
16-A A
12- 4
4-
I I I I I
16- B
12-
J--------l I ---- I
16- D >
12-
I I I 1 I I
0.5 1.0 1.5 2.0 2.5 3.0
FIC;RE ll.-Spectrograms recorded at Santa Margarita Lagoon. A-pattern SM-01, B-pattern SM-03, C-pattern SM-10, and D-pattern SM-11.
BULLETIN FLORIDA STATE MUSEUM
TABLE 4 (CONTINUED).
Pattern Number
Number Lettered Code in Sample
SE-03 AaBk4 PaHaKb HfDbEcJa 1
Los Penasquitos Estuary (N = 21)
LP-01 AaBc5 PaEaJn Ka EcFaJe 4
LP-02 AaBc5 KbEcEbKa EcFaJa 1
LP-03 Bc5 PaDaEc Ka EcFaJe 1
LP-04 Bc5 Ec2EbChPaEcJc Ka EcJa 3
LP-05 Bc5 KbDcOaKa EcFaJe 1
LP-06 AaBc4 KbEc2HcDcKa EcJa 1
LP-07 Bc6 ObDcJb Ka EcJa 1
LP-08 AaBc4 Hc2EbCa2DcHc Ka EcJa 2
LP-09 AaBe5 Ca3Da KaDaHcKb DcJe 1
LP-10 AaBc3 Ec2EbCgEbCa3Ec Ka EcFaJa 1
LP-11 AaBc4 CdEaEbOcObDc Ka EcJa 1
LP-12 AaBc6 PaEaEbHc2Dc Ka EcFaJe 3
LP-13 AaBc4 Ec2EbDaCe2Dc Ka EcJe 1
Imperial Beach (N = 8)
IB-01 Bm3 PfHdDa Ka DaFeCaEaFgJa 1
IB-02 AaBm2 Ca2Hd Ka DaFeCaDaFgJa 2
IB-03 AaBm4 PfDaHd Ka EaFeCaEaFgJa 3
IB-04 AaBm4 Ca4HdDa Ka EaFeCaEaFgJa 2
San Quintin Bay (N = 34)
SQ-01 AaBh3 Eb2CgEbCaOc KaObKb EaFcJb 1
SQ-02 AaBh3 EaEbCgEbCa30c Kb EaFbJb 3
SQ-03 AaBh5 JbEaCa KaOcKb EaFbJb 1
SQ-04 AaBh3 EaEbCgEb KaOcKb EaFbJb 6
SQ-05 Aa(2)Bh3 DaEbCgEbCgJm KaOcKb DaFbJb 2
SQ-06 AaBh3 OaEbCgEbCeOc Ka EcFbJa 5
SQ-07 Aa2B14 Eb2CgEb LaOcKa EcFbJa 3
SQ-08 Aa2B12 EaEb2CgEb LaOcKa EcPa 2
SQ-09 AaB13 EcEaEbCgEb LaOcKa EcFbJb 3
SQ-10 B16 CeEaJa Ka EcFbJb 3
SQ-11 AaB13 CaDcEb2CgEb LaOcKb EcFbJb 1
SQ-12 AaB13 CeEbCeEbCgEbJb Ka EcFbJa 1
SQ-13 AaB13 Eb2CgEbCdCa20c Ka EcFbJb 1
SQ-14 B14 EaEbCiCaOc Ka EcFbJb 1
SQ-15 B14 Ea2CiCeOc Ka EcJb 1
El Rosario (N = 11)
ER-01 Aa2Bn5 La DaJa I
ER-02 AaBn6 Lt DaJdCkDaJa 4
ER-03 AaBn5 La DiHdCkDaCkDaJa 6
'Notes or phrases occasionally omitted and numbers of repetitions that varied were placed in parentheses.
VARIATION IN PART III.-Variation within the main buzz section (Part
III) was relatively simple. Although many individuals from the various popu-
lations included a number of notes between successive buzzes, the basic pat-
tern of one or two K-type buzz phrases was maintained in most of the birds
sampled. Within most populations the number of buzzes was constant, but
Vol. 22, No. 2
12-
8--I
4-
16- B
12-
---,
16- D
12-
16-D
I I I I I I
0.5 1.0 15 2.0 2.5 3.0
FIG(URE 12.-Spectrograms recorded at San Elijo Lagoon and El Rosario. A-pattern SE-01, B-pattern SE-02, C-pattern ER-02, and D-pat-
tern ER-03.
BULLETIN FLORIDA STATE MUSEUM
there were several exceptions to this general rule. In a few localities the typi-
cal Ka or Kb buzzes were replaced by La, Ma, or Na buzz phrases. In the main
buzz sections of the entire sample 24 I found different note types, but most
birds included only two to four notes between any two successive buzzes.
VARIATION IN PART IV.-Variation between the different populations is
best demonstrated by analysis of Part IV. This terminal flourish portion of the
songs was rather constant at a given location. Each population had one or a
few characteristic patterns. Considerable variation existed among the several
recording localities. This diversity took the form of variation in the number of
notes, the general note sequence, and in some cases the structure of certain
notes. The number of notes included ranged from two to eight. Most of the
notes were of the general types D, E, F, I, and J. All but 7 of the 280 birds re-
corded in this study terminated their songs with a J-type note.
SUMMARY OF INTERPOPULATIONAL VARIATION BY LOCATION
01 GOLETA SLOUGH.-Santa Barbara, Santa Barbara County, California,
close to the Santa Barbara municipal airport. The marsh is fairly large with
a deep channel running down the center. The population of sparrows was
probably fewer than 50 pairs. Recordings were made on 25 May of only eight
individuals (Fig. 5). The songs of these birds had many short introductory notes
of type Bg. The two buzzes present were separated by a single note and the
terminal flourish was consistently of four notes.
02 EL ESTERO.-Less than 1 mile west of Carpinteria, Santa Barbara
County, California. Although this marsh was being channelized, a large num-
ber of sparrows were still singing there. The population was estimated at 100
breeding pairs. Recordings were made on 11 May of a total of 28 individuals
(Fig. 6). The introductory notes were similar to those recorded from birds
at Goleta Slough, with from four to seven Bg notes followed by a series of C
notes or a P-type buzz. The number of K-type buzzes varied. The terminal
flourish usually consisted of three simple notes followed by a short Jb note.
03 POINT Mucu.-In the Pacific Missile Range, about 5 miles southeast of
Port Hueneme, Ventura County, California. This area was visited on 4 May.
Recordings were restricted to the eastern finger of the estuary, near Point
Mugu State Park. Songs of 28 of the estimated 175 singing males were re-
corded (Fig. 7). The initial pattern BhBi2 gave their songs a recognizable
opening. The main buzz was quite long (up to 0.7 seconds). Part IV consisted
of three to four notes usually with an Ib note and ending with a Jb note. Three
individuals used a very distinctive harsh buzz constructed of numerous Cl
notes.
04 PLAYA DEL REY.-Just east of Marina del Rey, Los Angeles County,
California. Recordings were made on July 21. Although only 4 of the esti-
mated 25 males were recorded, several others that I heard were using similar
Vol. 22, No. 2
4 ~
1% ~ ~sb 4 4-4-4*jAw_%__ft
4w
0.5 1.0 1.5 2.0 2.5 3.0
F HI(,cE 13.-Spectrograms recorded at Los Penasquitos Estuary. A-pattern LP-01, B-pattern LP-04, C-pattern LP-08, and D-pattern LP-12.
BULLETIN FLORIDA STATE MUSEUM
song patterns (Fig. 5). The songs recorded here had no B notes, and several
short C, D, and E notes formed the introduction; Parts II and III consisted of
a P buzz followed by a single note then a K buzz. The terminal flourish was
composed of only three notes ending with a short J-type note.
05 ANAHEIM BAY.-Seal Beach National Wildlife Refuge, Seal Beach,
Orange County, California. Anaheim Bay was the main study area where I
made observations of individual variation and seasonal variation. In addition
to recording 61 individuals, I color-banded a number of birds for individual
recognition. I estimated the population here to be approximately 125 singing
males. Recordings were made on the following dates: 2, 7, 14, 17, and 26
February, 3 March, 2 and 21 April, 12 and 20 May, 29 August 1973, and 10
February 1974 (Fig. 8). The songs of birds recorded at this locality began with
three or four Bb notes followed by a P buzz or a series of C notes forming a
buzzlike phrase. Part III had only one K-type buzz. The terminal flourish
usually consisted of the pattern FdFeJa with a rather long Ja note.
06 HUNTINGTON HARBOUR.-Sunset Beach, Orange County, California. As
mentioned earlier this area and Bolsa Chica Lagoon (07) to the east were both
once part of the Anaheim Bay marsh complex. The combined population of
Huntington Harbour and Bolsa Chica Lagoon is about 50 pairs. Five birds
were recorded at Huntington Harbour on 6 June (Fig. 9). The patterns of their
songs were similar to those recorded at Anaheim Bay.
08 NEWPORT BAY.-Less than 1 mile northeast of Newport Beach, Orange
County, California. Although this is the largest estuary that I visited in Cali-
fornia, the habitat was mostly Spartina and open mudflats. The portion of the
estuary where Salicornia occurred supported about 130 breeding pairs of
Belding's Sparrows. Recordings were made on 2 February and 16 March of a
total of 30 males on the two visits (Fig. 10). The songs of these birds bore some
resemblance to those recorded at Anaheim Bay. They had a variable number
of introductory notes (usually four to seven), and either one or two K-type
buzzes. In the song patterns containing only one K buzz it was usually pre-
ceded by a P buzz in Part II. The distinctive four-note terminal flourish
EaFaFdJa was characteristic of this location.
09 SANTA MARGARITA LAGOON.-On Camp Joseph H. Pendleton just north
of Oceanside, San Diego County, California, this estuary supported approxi-
mately 125 singing males. A sample of 29 birds was recorded on 28 April
(Fig. 11). Most of the song patterns included three of the relatively long Bk in-
troductory notes. Two K-type buzzes were present in the songs. The first was
usually a Ka buzz about 0.4 seconds long; the second was a Kh buzz about
0.25 seconds long. The song ended with three notes usually of the pattern
IcDaJa. Three individuals used the highly distinctive Na buzz in their songs.
10 AGUA HEDIONDA LAGOON.-Carlsdad, San Diego County, California.
Recordings were made at this area on 24 March (Fig. 9). Although only 10 of
Vol. 22, No. 2
-~ ~,, iii.
12-
a-
16- C
12
8-
4-
I I I I I I
0.5 1.0 1.5 2.0 2.5 3.0
FIGURE 14.-Spectrograms recorded at Imperial Beach and San Quintin Bay. A-pattern IB-02, B-pattern IB-03, C-pattern IB-04, and D-
pattern SQ-02.
BULLETIN FLORIDA STATE MUSEUM
the nearly 40 singing males were recorded, at least 8 more birds shared the
same song patterns. The introduction included both Bh and Bk notes. Con-
sistently two K-type buzzes were separated by two shorter notes. The terminal
flourish consisted of only two notes, the last being a Ja.
11 SAN ELIJO LAGOON.-About 0.5 miles south of Cardiff-by-the-Sea, San
Diego County, California. The small portion of this marsh which remained
intact supported only about 17 pairs of Belding's Sparrows. On 26 March I
recorded four males (Fig. 12), and their songs were similar to at least 12 other
males I heard here. As far as I could determine, of 17 males defending terri-
tories here only individual 11-01 did not use three Kb buzzes. Part II of the
songs was nearly absent. The song patterns were characterized by the three
short buzzes. Only two terminal notes follow the second Kb buzz.
12 Los PENASQUITOS ESTUARY.-About 2 miles south of Del Mar, San
Diego County, California. This large Salicornia marsh is the estuary where
Penasquitos Creek meets the ocean. Although some development had oc-
curred at the southwest end of the marsh, it still maintained a population of
approximately 160 breeding pairs. On 6, 8, and 29 April I recorded 21 indi-
viduals (Fig. 13). At least four to five B notes characterized the introductory
phrase of songs recorded here. There were usually two K buzzes and fre-
quently a Pa buzz. The terminal portion of the songs included two or three
notes, EcJa and EcFaJa being the common patterns.
13 IMPERIAL BEACH.-About 2 miles south of Imperial Beach at the mouth
of the Tijuana River, San Diego County, California. This area supported a
population of approximately 100 breeding pairs, but the constant heavy winds
made recording difficult. I recorded only eight individuals on 1 April (Fig. 14).
Even though the sample was small, I believe that it was representative of the
song patterns of the birds here. The unique Bm notes make up the introduc-
tory portion of their song. A single Pf buzz or a few C notes forming a buzz-
like phrase were usually followed by a long K-type buzz (0.5 to 0.6 seconds).
Part IV was long and included six notes.
14 ENSENADA BAY.-Ensenada, Baja California Norte, Mexico. Although
most of the habitat at Ensenada Bay was dominated by Spartina, several local
areas of Salicornia persist. These areas supported perhaps 20 pairs of Beld-
ing's Sparrows. Unfortunately none could be recorded in the time available.
15 SAN QUINTIN.-The eastern arm of San Quintin Bay, 15 miles south of
Colonia Guerrero, Baja California Norte, Mexico. This huge tidal salt marsh
supported a population of at least 2000 breeding pairs. I recorded birds on
the east side of the inner bay on 15 April, and the west side on 16 April (Fig.
15). The sample of 34 birds recorded here was deemed representative of the
different song patterns present in this population. The Aa and Bh notes com-
bined with a pattern of E and C notes to produce a distinctive "see-saw"
rhythm in the introduction. One or two closely spaced K-type buzzes were
often followed by the three note terminal phrase E F J.
Vol. 22, No. 2
16 A
12-
4-
I I I I I I
12-
8-wI
16-B
18-
I I I I I
16- D
12- ,
4-
I I I I I I
0.5 1.0 1.5 2.0 2.5 3.0
FIC;LRE 15.-Spectrograms recorded at San Quintin Bay. A-pattern SQ-04, B-pattern SQ-06, C-pattern SQ-07, and D-pattern SQ-09.
BULLETIN FLORIDA STATE MUSEUM
16 EL RosARio.-Laguna El Rosario, about four miles west of El Rosario,
Baja California Norte, Mexico. I made recordings of 11 of the 50 singing males
at this location on 14 April (Fig. 12). The five or six introductory notes had a
whistled quality. Part II of the songs was entirely absent. Rather long harsh
La buzzes characterized Part III. The terminal phrase usually included be-
tween four and six short high pitched notes followed by a Ja note.
DISCUSSION
The pattern of geographic variation in the Belding's Sparrow songs was
rather complex. Each individual sang only one specific song pattern. Differ-
ent individuals within a given population each sang one of a number of dis-
tinct song patterns. One or two song patterns were usually dominant at each
location. Certain vocal characteristics were shared by the members of each
population, and these distinguished them from birds recorded at other sites. I
documented variation in the number and structure of particular notes as well
as alteration of the entire song pattern. Although the songs of Belding's Spar-
row are complicated, a mosaic pattern of variation was evident.
The fact that distinguishable song dialects occurred in the isolated popu-
lations of these sparrows is not surprising. Similar patterns of geographical
song variation in other species have been demonstrated by many authors
(Marler 1952, Marler and Tamura 1962, Ward 1966, Nottebohm 1969,
Thielcke 1969, Harris and Lemon 1972, and Grimes 1974). The presence of
well-defined dialects over such short distances is more interesting. The cur-
rent study involved recordings from a single subspecies (P. s. beldingi). Other
studies have sometimes involved more than one subspecies over much greater
distances (Nottebohm 1969). Evidently the sedentary nature of Belding's Sa-
vannah Sparrow and its specific habitat requirements have produced effec-
tive isolation over distances as short as 15 to 30 miles.
If geographical variation, taking the form of well defined dialects, is com-
mon in isolated populations of certain species, one may ask how such varia-
tion evolves. Perhaps even more important is the question of dialect function
in speciation. A possible mechanism for the development of vocal dialects in-
volves preferential mating of females with males having particular vocal char-
acteristics. This mechanism has been proposed before (Nottebohm 1969, King
1972). Some evidence exists that assortative mating does not occur. Baptista
(1974) found that males singing the "wrong" song dialect were successful in
attracting mates, but it is important to note that assortative mating would
most likely be a statistical event. A tendency for females to choose males with
"correct" songs is sufficient to affect selection.
If we assume that a female sparrow is "coded" to respond to the song typi-
cal of her species, it follows that she might be so coded on a particular variant
of that song. The song to which developing females (and males) are first ex-
Vol. 22, No. 2
BRADLEY: BELDING'S SAVANNAH SPARROW
California
FIGURE 16.-Map localities and type B note variants. Boxes near each recording locality show
basic structure of B-type note variant or variants used by members of that population. Numbers
refer to the location numbers listed in Table 1. Again numbers 07 and 14 are omitted as no birds
were recorded at Bolsa Chica Lagoon or Ensenada Bay. No illustration is indicated for location
04 (Playa del Rey) because B-type notes were absent from songs of birds recorded there.
1977
BULLETIN FLORIDA STATE MUSEUM
posed is that of the male parent. If young females respond most strongly to this
song pattern, the most prolific (fit) males would sing the most popular song
patterns. The occurrence of clustering in males with similar song patterns, as
observed in this study, would tend to enhance this process. Both male and fe-
male juveniles would thus be exposed predominately to one song pattern.
That higher passerines can distinguish between songs of different individ-
uals has been shown by several authors (Marler 1956, Weeden and Falls 1959,
Falls 1969, and Emlen 1971b). These studies involved responses of territorial
males to recorded songs. To my knowledge, only two field studies of differen-
tial responses in adult females have been conducted. Bertram (1970) demon-
strated that individual female Indian Hill Mynahs (Gracula religiosa) recog-
nized their mates by vocal characteristics. Milligan and Verner (1971) men-
tioned that female White-crowned Sparrows responded more strongly to the
local dialect. Differential responses to songs of different dialects have also
been shown in territorial males (Lemon 1967, Milligan and Verner 1971,
Thielcke 1973, and Harris and Lemon 1974). Again little field data are avail-
able for the responses of mature females.
The presumed function of song in attracting the female is critical to any
discussion of song as an isolating mechanism. This advertising function of song
has been shown for several species (Quaintance 1938, Nice 1943, Woolfenden
1956, Smith 1959, Catchpole 1973). In addition, Payne (1973a) demonstrated
a high degree of assortative mating between Indigobirds imprinted upon spe-
cific mimetic songs. Positive responses have also been elicited in captive fe-
males to recordings of the advertising songs of males (Payne 1973b). Record-
ings of song stimulate approach in female Chaffinches (Marler 1956). Female
White-throated Sparrows may even assume a soliciting posture and utter pre-
copulatory vocalizations in response to male song (Falls 1969).
Specific functions of the song in the Savannah Sparrows are undocu-
mented. At least part of the function includes the establishment and reten-
tion of discrete territories by the singing males. There seems little doubt that
the behavior of the male during song makes him conspicuous to females seek-
ing a mate. While these sparrows spend most of their time on or near the
ground, song is nearly always given from an exposed perch, often well above
the surrounding vegetation.
If song dialects are truly an important mechanism of behavioral isolation,
evidence should exist of morphological or genetic variation between different
dialect groups. The interaction of a dialect system with the occurrence of
certain genes was shown by Nottebohm and Selander (1972) in Zonotrichia
capensis. King (1972), in another study of Z. capensis, showed a correlation
between song themes and the specific habitat in which the sparrows occurred.
He also included some morphological data on the birds from each area. Baker
(1975) found genetic differences between dialect groups in White-throated
Sparrows. In the same paper he presented data showing allelic variation in
Vol. 22, No. 2
BRADLEY: BELDING'S SAVANNAH SPARROW
another population where no dialects exist. Preliminary work that I have con-
ducted on Orange-crowned Warblers (Vennicora celata) has revealed that the
darker insular race (sordida) has a distinctly slower trill than the brightly
colored mainland race (letitescens). In studies of very closely related species,
differences in their vocalizations are often cited as possible isolating mech-
anisms (Lanyon 1957, Stein 1958, Schwartz 1972, Thielcke 1973).
Adaptive radiation within the coastal species of North American emberi-
zine sparrows is extensive. Several marsh nesting species such as the Seaside
Sparrow (Ammospiza maritima) and the Sharp-tailed Sparrow (A. caudacita)
have a number of different morphological variants. Along the west coast of
North America, no fewer than 11 different subspecies of the Savannah Spar-
row are currently recognized (American Ornithologists' Union Check-list
1957). Along the eastern coast of the continent are many marsh-inhabiting
sparrows including several distinct species. Beecher (1955) believed that the
Seaside Sparrows and the Sharp-tailed Sparrows were originally derived from
Savannah Sparrow stock. It seems evident that speciation in coastal popula-
tions of North American sparrows is progressing at a relatively rapid rate. If
song dialects are indeed an important isolating mechanism, they may play a
significant role in such rapid speciation.
LITERATURE CITED
American Ornithologists' Union. 1957. Check-list of North American birds, 5th ed. Lord Balti-
more Press, Baltimore, Md. 691 pp.
American Ornithologists' Union. 1973. Thirty-second supplement to the American Ornithologists'
Union Check-list of North American birds. Auk 90:411-419.
Armstrong, E. A. 1973. A study of bird song, 2nd ed. Dover Publications, Inc., New York. 343 pp.
Baker, M. C. 1975. Song dialects and genetic differences in White-crowned Sparrows (Zono-
trichia leucophrys). Evol. 29:226-241.
Baptista, L. F. 1974. The effects of songs of wintering White-crowned Sparrows on song devel-
opment in sedentary populations of the species. Z. Tierpsychol. 34:147-171.
Beechet, W. J. 1955. Late-Pleistocene isolation of saltmarsh sparrows. Ecology 36:23-26.
Bent, A. C. (0. L. Austin, Jr., ed.) 1968. Life histories of North American Cardinals, Grosbeaks,
Buntings, Towhees, Finches, Sparrows, and allies. Order Passeriformes: Family Fringilli-
dae. Genera Pipilo (part) through Spizella. U.S.N.M. Bull. No. 237. Smithsonian Inst. Press.
Bertram, B. 1970. The vocal behavior of the Indian Hill Mynah, Gracula religiosa. Anim. Behav.
Monogr. 3:80-192.
Borror, D. J. 1956. Variation in Carolina Wren songs. Auk 73:211-229.
1961a. Intraspecific variation in passerine bird song. Wilson Bull. 73:57-78.
1961b. Songs of finches (Fringillidae) of eastern North America. Ohio J. Sci. 61:161-
174.
1965. Song variation in Maine Song Sparrows. Wilson Bull. 77:5-37.
Bradley, R. A. 1973. A population census of the Belding's Savannah Sparrow, Passerciulus sanmd-
uicihensis beldingi. Western Bird Bander 48:40-43.
Catchpole, C. K. 1973. The functions of advertising song in the Sedge Warbler (Acrocephallus
schoenobaenus) and the Reed Warbler (A. scirpaceus). Behaviour 46:300-319.
Chapman, R. M. 1896. Handbook of birds of eastern North America, 3rd ed. D. Appleton and
Co., New York. 427 pp.
BULLETIN FLORIDA STATE MUSEUM
Conrads, K. and W. Conrads. 1971. Regionaldialekte des Ortolans (Emberiza hortulana) in
Deutschland. Die Vogelwelt 92:81-100.
DeWolfe, B. B., D. D. Kaska, and L. J. Peyton. 1974. Prominent variations in the songs of
Gambel's White-crowned Sparrows. Bird-banding 45:224-252.
Emlen, S. T. 1971a. An experimental analysis of the parameters of bird song eliciting species
recognition. Behaviour 41:130-171.
1971b. The role of song in individual recognition in the Indigo Bunting. Z. Tierpsy-
chol. 28:241-246.
Falls, J. B. 1969. Functions of territorial song in the White-throated Sparrow. Pages 207-232 in
R. A. Hinde, ed. Bird vocalizations. Cambridge University Press, London.
Gobiel, R. E. 1970. Vocalizations of the Savannah Sparrow. Bird-banding 41:18-21.
Greenewalt, C. H. 1968. Bird song: acoustics and physiology. Smithsonian Institute Press, Wash-
ington, D.C. 194 pp.
Grimes, L. G. 1974. Dialects and geographical variation in the song of the Splendid Sunbird
Nectarine coccinigaster. Ibis 116:314-329.
Harris, M. A. and R. E. Lemon. 1972. Songs of Song Sparrows (Melospiza imelodia): Individual
variation and dialects. Canad. J. Zool. 50:301-309.
1974. Songs of Song Sparrows: reactions of males to songs of different localities.
Condor, 76:33-44.
Jilka, A. and B. Leisler. 1974. Die Einpassung dreier Rohrsangerarten (Acrocephalus schoeno-
baenus, A. scirpaceus, A. arundinaceus) in ihre Lebensraume in bezug auf das Frequenzspec-
trum ihrer Reviergesange. J. Ornithol. 115:192-212.
King, J. R. 1972. Variation in the song of the Rufous-collared Sparrow (Zonotrichia capensis)
in northwestern Argentina. Z. Tierpsychol. 30:344-373.
Kroodsma, D. E. 1974. Song learning, dialects and dispersal in the Bewick's Wren. Z. Tierpsy-
chol. 35:352-380.
Lanyon, W. E. 1957. The comparative biology of the Meadowlarks (Stnrnella) in Wisconsin.
Publ. Nuttall Ornithological Club 1:1-67.
__ 1960. The ontogeny of vocalizations in birds. Pages 321-347 in W. E. Lanyon and
W. N. Tavolga, eds. Animal sounds and communication. American Institute of Biological
Science, Washington, D.C.
1969. Vocal characters and avian systematics. Pages 291-310 in R. A. Hinde, ed.
Bird vocalizations. Cambridge University Press, London.
Lemon, R. E. 1966. Geographic variation in the song of Cardinals. Canad. J. Zool. 44:413-428.
1967. The response of Cardinals to songs of different dialects. Anim. Behav. 15:538-
545.
Marler, P. 1952. Variations in the song of thv Chaffinch, Fringilla coelebs. Ibis 94:458-472.
1956. The voice of the Chaffinch and its function as a language. Ibis 98:231-261.
1967. Comparative study of song development in sparrows. Proc. 14th Int. Ornith.
Congr. Blackwells, Oxford, pp. 231-244.
Marler, P. and M. Tamura. 1962. Song "dialects" in three populations of White-crowned Spar-
rows. Condor 64:368-377.
1964. Culturally transmitted patterns of vocal behavior in sparrows. Science
146:1483-1486.
Mayr, E. 1963. Animal species and evolution. The Belknap Press. Cambridge, Mass. 797 pp.
Milligan, M. M. and J. Verner. 1951. Inter-populational song dialect discrimination in the White-
crowned Sparrow. Condor 73:208-213.
Morton, E. S. 1975. Ecological sources of selection on avian sounds. Amer. Naturalist 108:17-34.
Mulligan, J. A. 1966. Singing behavior and its development in the Song Sparrow, Melospiza
melodia. Univ. Calif. Publ. Zool. 81:1-76.
Nice, M. M. 1943. Studies in the life history of the Song Sparrow. II. The behavior of the Song
Sparrow and other passerines. Trans. Linnaean Soc. of New York 6:1-328.
Nottebohm, F. 1969. The song of the Chingolo, Zonotrichia capensis, in Argentina: Descrip-
tion and evaluation of a system of dialects. Condor 71:299-315.
1972. The origins of vocal learning. Amer. Naturalist 106:116-140.
Nottebohm, F. and R. K. Selander. 1972. Vocal dialects and gene frequencies in the Chingolo
Sparrow (Zonotrichia capensis). Condor 74:137-143.
Vol. 22, No. 2
BRADLEY: BELDING'S SAVANNAH SPARROW
Orejuela, J. E. and M. L. Morton. 1975. Song dialects in several populations of Mountain White-
crowned Sparrows (Zonotrichia leucophrys oriantha) in the Sierra Nevada. Condor 77:145-
153.
Payne, R. B. 1973a. Behavior, mimetic songs and song dialects, and relationships of the parasitic
Indigobirds (Vidua) of Africa. Orn. Monogr. 11:1-333.
1973b. Vocal mimicry of the paradise whydas (Vidua) and response of female why-
dahs to the songs of their hosts (Pytilia) and their mimics. Anim. Behav. 21:762-771.
Poulsen, H. 1951. Inheritance and learning in the song of the Chaffinch (Fringilla coelebs L.).
Behaviour 3:216-228.
Quaintance, C. W. 1938. Context, meaning and possible origin of males song in the Brown Tow-
hee. Condor 40:97-101.
Ridgway, R. 1885. Some emended names of North American birds. Proc. U. S. Nat. Mus. 8:354-
356.
Schwartz, P. 1972. Micrastur gilricollis, a valid species sympatric with M.. ruficollis in Amazonia.
Condor 74:399-415.
Smith, R. L. 1959. The songs of the Grasshopper Sparrow. Wilson Bull. 71:141-152.
Stein, R. C. 1958. The behavioral, ecological and morphological characteristics of two popula-
tions of the Alder Flycatcher, Empidonax traillii (Audubon). Bull. New York State Mus. Sci.
Serv. 371:1-63.
Thielcke, G. 1969. Geographic variation in bird vocalizations. Pages 311-339 in R. A. Hinde, ed.
Bird vocalizations. Cambridge University Press, London.
1973. On the origin of divergence of learned signals (songs) in isolated populations.
Ibis 115:511-516.
Thompson, W. L. 1970. Song variation in a population of Indigo Buntings. Auk 87:58-71.
Thorpe, W. H. 1958. The learning of song-patterns by birds, with especial reference to the song
in the Chaffinch Fringilla coelebs. Ibis 100:535-570.
1961. Bird-song. Cambridge University Press, London. 143 pp.
van Rossem, A. J. 1947. A synopsis of the Savannah Sparrows of northwestern Mexico. Condor
49:97-107.
Ward, R. 1966. Regional variation in the song of the Carolina Chickadee. Living Bird 5:127-150.
Weeden, J. S. and J. B. Falls. 1959. Differential responses of male Ovenbirds to recorded songs
of neighboring and more distant individuals. Auk 76:343-351.
Woolfenden, G. E. 1956. Comparative breeding behavior of Amnmospiza caudacuta and A. mari-
tima. University of Kansas Publ. 10:45-75.
Contributions to the BULLETIN OF THE FLORIDA STATE MUSEUM, BIOLOGICAL SCI-
ENCES SERIES, may be in any field of biology. Manuscripts dealing with natural history of
systematic problems involving the southeastern United States or the New World tropics are
solicited especially. Manuscripts should be of medium length-circa 35 to 200 pages (10,500-
16,000 words). Examination for suitability is made by an Editorial Board.
The BULLETIN is distributed worldwide through institutional subscriptions and exchanges.
It is considered the responsibility of the author to distribute his paper to all interested individ-
uals. To aid in this the authors) receives) 50 copies free, and he may purchase additional
separates at cost if ordered when page proof is returned. The author is also responsible for any
charges incurred for alterations made by him on galley or page proofs. The Museum will send
an invoice to the author for this amount upon completion of publication.
PREPARATION OF MANUSCRIPT
Contributors should consult recent numbers of the BULLETIN for preferred style and format.
Highly recommended as a guide is the CBE Style Manual, 3rd Edition, 1972 (Washington, D.C.,
Amer. Inst. Biol. Sci.).
MSS must be submitted in duplicate (please no onionskin) and satisfy the following minimal re-
quirements: They should be typewritten, double-spaced (especially tables, figure captions, and
"Literature Cited"), on one side of numbered sheets of standard (8-1/2 X 11 in.) bond paper,
with at least one-inch margins all around. Figure legends and tables should be typed on separate
sheets. All illustrations are referred to as figures. They must comply with the following stan-
dards: Photographs should be sharp, with good contrast, and printed on glossy paper. Drawings
should be made with dense black waterproof ink on quality paper or illustration board. All il-
lustrations should have a cover sheet. All lettering will be medium weight, sans-serif type (e.g.
Futura Medium, News Gothic) in cutout, dry transfer, or lettering guide letters. Make allow-
ance so that after reduction no lowercase letter will be less than 1 mm high (2 mm is preferred)
nor any capital letter greater than 5 mm high. The maximum size for illustrations is 8-5/8 x 14 in.
(twice typepage size); illustrations should not be less than typepage width (4-5/16 in.). Designate
the top of each illustration and identify on the back with soft pencil by author's name, MS title,
and figure number.
All manuscripts not submitted in BULLETIN format will be returned to the author for retyping.
Manuscripts and all editorial matters should he addressed to:
Managing Editor of the BULLETIN
Florida State Museum
Museum Road
University of Florida
Gainesville. FL 32611
|
