Melospiza georgiana: BirdLife International

2018 ◽  
Author(s):  
Keyword(s):  
Melospiza Georgiana

Kinematics of birdsong: functional correlation of cranial movements and acoustic features in sparrows

1993 ◽  
Vol 182 (1) ◽  
pp. 147-171 ◽  
Author(s):  
M. W. Westneat ◽  
J. H. Long ◽  
W. Hoese ◽  
S. Nowicki
Keyword(s):  
Vocal Tract ◽  
Active Role ◽  
Acoustic Properties ◽  
Zonotrichia Albicollis ◽  
Low Frequencies ◽  
Acoustic Frequency ◽  
Mean Frequency ◽  
Singing Behavior ◽  
Resonance Properties ◽  
Melospiza Georgiana

The movements of the head and beak of songbirds may play a functional role in vocal production by influencing the acoustic properties of songs. We investigated this possibility by synchronously measuring the acoustic frequency and amplitude and the kinematics (beak gape and head angle) of singing behavior in the white-throated sparrow (Zonotrichia albicollis) and the swamp sparrow (Melospiza georgiana). These birds are closely related emberizine sparrows, but their songs differ radically in frequency and amplitude structure. We found that the acoustic frequencies of notes in a song have a consistent, positive correlation with beak gape in both species. Beak gape increased significantly with increasing frequency during the first two notes in Z. albicollis song, with a mean frequency for note 1 of 3 kHz corresponding to a gape of 0.4 cm (a 15 degrees gape angle) and a mean frequency for note 2 of 4 kHz corresponding to a gape of 0.7 cm (a 30 degrees gape angle). The relationship between gape and frequency for the upswept third note in Z. albicollis also was significant. In M. georgiana, low frequencies of 3 kHz corresponding to beak gapes of 0.2-0.3 cm (a 10–15 degrees break angle), whereas frequencies of 7–8 kHz were associated with flaring of the beak to over 1 cm (a beak angle greater than 50 degrees). Beak gape and song amplitude are poorly correlated in both species. We conclude that cranial kinematics, particularly beak movements, influence the resonance properties of the vocal tract by varying its physical dimensions and thus play an active role in the production of birdsong.

scholarly journals Swamp sparrows modulate vocal performance in an aggressive context

2008 ◽  
Vol 5 (2) ◽  
pp. 163-165 ◽  
Author(s):  
Adrienne L DuBois ◽  
Stephen Nowicki ◽  
William A Searcy
Keyword(s):  
Upper Bound ◽  
Vocal Performance ◽  
Frequency Bandwidth ◽  
Aggressive Communication ◽  
Melospiza Georgiana ◽  
Song Types

Vocal performance refers to the proficiency with which a bird sings songs that are challenging to produce, and can be measured in simple trilled songs by their deviation from an upper bound regression of frequency bandwidth on trill rate. Here, we show that male swamp sparrows ( Melospiza georgiana ) increase the vocal performance of individual song types in aggressive contexts by increasing both the trill rate and frequency bandwidth. These results are the first to demonstrate flexible modulation by songbirds of this aspect of vocal performance and are consistent with this signal feature having a role in aggressive communication.

scholarly journals Stable-Isotope (C, N, H) Analyses Help Locate the Winter Range of the Coastal Plain Swamp Sparrow (Melospiza Georgiana Nigrescens)

The Auk ◽  
2007 ◽  
Vol 124 (4) ◽  
pp. 1137-1148 ◽  
Author(s):  
Russell Greenberg ◽  
Peter P. Marra ◽  
Matthew J. Wooller
Keyword(s):  
South Carolina ◽  
Stable Isotope ◽  
Coastal Plain ◽  
Isotope Analysis ◽  
Coastal Region ◽  
Breeding Habitat ◽  
Δ13c And Δ15n ◽  
Swamp Sparrow ◽  
Brackish Marshes ◽  
Melospiza Georgiana

Abstract Some taxa of North American birds have unknown winter ranges, because of the difficulty in tracking individuals between seasons. Stable isotopes may provide clues to help locate these nonbreeding populations. Previously, no valid records existed for the Coastal Plain Swamp Sparrow (Melospiza georgiana nigrescens) from October to late April. We used stable-isotope (C, N, and H) analyses to provide estimates of where molt occurs and then searched those areas for individuals of this species. The δ13C and δ15N of rump feathers were consistent with the Coastal Plain Swamp Sparrow molting in more saline marshes than the nominate subspecies after the breeding season, which confirms what was already known. The values for the same isotopes from crown feathers revealed that winter molt in the Coastal Plain Swamp Sparrow probably occurred in similar coastal brackish habitats. The δD of crown feathers indicated that prebreeding molt occurred at latitudes between South Carolina and Virginia. A subsequent search of this region located 18 Coastal Plain Swamp Sparrows, all of which were found in North Carolina or southeastern Virginia. Coastal Plain Swamp Sparrows were found predominantly in brackish marshes similar to their breeding habitat. On the basis of these observations, it appears that Coastal Plain Swamp Sparrows undergo a short southerly migration to a coastal region with substantially warmer winter conditions. This study is the first to make a specific geographic prediction based on stable-isotope analysis and to test the prediction in the field. Análisis de Isótopos Estables (C, N, H) Ayudan a Localizar la Distribución Invernal de Melospiza georgiana nigrescens

The Response of Swamp Sparrows To Acoustically Distinct Song Types

Behaviour ◽  
1982 ◽  
Vol 80 (1-2) ◽  
pp. 70-83 ◽  
Author(s):  
Peter Marler ◽  
Margaret H. Searcy ◽  
William A. Searcy
Keyword(s):  
Song Type ◽  
Repeated Presentation ◽  
Swamp Sparrow ◽  
Differential Reaction ◽  
Different Types ◽  
Melospiza Georgiana ◽  
Previously Treated ◽  
To Come ◽  
Song Types ◽  
Measured Response

AbstractMale and femal swamp sparrows (Melospiza georgiana) were tested for differential reaction to four acoustically distinct swamp sparrow song types. We tested males by playing bouts of single song types from speakers placed on male territories. Males gave the same kinds of aggressive responses to each of the four song types, and there were no quantitative differences in the strengths of the responses to the different types. In the experiments with females, we played songs to captive female swamp sparrows previously treated with estradiol, and measured response in terms of copulation solicitation display. Females displayed in response to all four song types, and again there were no quantitative differences in the strength of response to the different types. We conclude that different swamp sparrow song types do not convey different messages to either male or female listeners. Although the identity of the particular song type presented was unimportant, the number of types presented was important, at least to females. Females responded more strongly overall to bouts of four song types than to bouts of single song types. This result occurred because females habituated to the repeated presentation of a single song type, and showed a recovery in response when song types were switched. We conclude that the ability to sing multiple song types may aid males in stimulating females to come into reproductive condition and then copulate.

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