@article {57346,
	title = {Evidence for differing trajectories of songs in urban and rural populations},
	journal = {Behavioral Ecology},
	year = {2019},
	month = {Jul-08-2020},
	abstract = {<p>Learned traits, such as foraging strategies and communication signals, can change over time via cultural evolution. Using historical recordings, we investigate the cultural evolution of birdsong over nearly a 50-year period. Specifically, we examine the parts of white-crowned sparrow (Zonotrichia leucophrys nuttalli) songs used for mate attraction and territorial defense. We compared historical (early 1970s) recordings with contemporary (mid-2010s) recordings from populations within and near San Francisco, CA and assessed the vocal performance of these songs. Because birds exposed to anthropogenic noise tend to sing at higher minimum frequencies with narrower frequency bandwidths, potentially reducing one measure of song performance, we hypothesized that other song features, such as syllable complexity, might be exaggerated, as an alternative means to display performance capabilities. We found that vocal performance increased between historical and contemporary songs, with a larger effect size for urban songs, and that syllable complexity, measured as the number of frequency modulations per syllable, was historically low for urban males but increased significantly in urban songs. We interpret these results as evidence for males increasing song complexity and trilled performance over time in urban habitats, despite performance constraints from urban noise, and suggest a new line of inquiry into how environments alter vocal performance over time.</p>
},
	keywords = {anthropogenic noise, birdsong, Cultural evolution, sexual selection, Urbanization, vocal performance},
	issn = {1045-2249},
	doi = {10.1093/beheco/arz142},
	url = {https://academic.oup.com/beheco/advance-article/doi/10.1093/beheco/arz142/5551107},
	author = {Moseley, Dana L and Jennifer N. Phillips and Derryberry, Elizabeth P and David A. Luther},
	editor = {Candolin, Ulrika}
}
@article {53424,
	title = {The buzz segment of Savannah sparrow song is a population marker},
	journal = {Journal of Ornithology},
	year = {2018},
	month = {Mar-12-2018},
	abstract = {<p>Different components of learned birdsongs change at different rates across generations, and the rate of change may correspond to the information carried by each component. To characterize the role of the buzz segment of Savannah sparrow songs, we examined recordings from southeastern Canada and the northeastern US and fully characterized buzz segments in songs recorded from two populations: one on Kent Island, NB, Canada and another in Williamstown, MA, USA. Buzzes varied geographically: Kent Island buzzes had higher mean frequencies and shorter pulse periods than Williamstown buzzes and the differences between the two populations persisted over time. Population-specific buzz characteristics also appeared to be resistant to change. Variants appeared on Kent Island in the late 1980s and were learned by some younger birds; however, these buzz variants disappeared by 2011. We conducted a playback experiment and found that males from both populations had longer responses to local buzzes. Therefore, buzz structure varies geographically; population characteristics of the buzz persist through time despite the introduction of variant forms; and territorial males discriminate between buzzes from different populations. The learned buzz segment of the song may thus serve as a population marker for Savannah sparrows.</p>
},
	keywords = {Cultural evolution, dialect, Passerculus sandwichensis, playback, Population, song},
	issn = {2193-7192},
	doi = {10.1007/s10336-018-1611-7},
	url = {http://link.springer.com/10.1007/s10336-018-1611-7},
	author = {Williams, Heather and Robins, Clint W. and Newman, Amy E. M. and Freeman-Gallant, Corey R. and Wheelwright, Nathaniel T. and Mennill, Daniel J.}
}
