02270nas a2200241   4500008004100000022001400041245008000055210006900135260001600204520148200220653002401702653001301726653002301739653002101762653001701783653002201800100002101822700002701843700002901870700002201899700002101921856008601942       2019                        eng d  a1045-224900aEvidence for differing trajectories of songs in urban and rural populations0 aEvidence for differing trajectories of songs in urban and rural   cJul-08-20203 a<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>
10aanthropogenic noise10abirdsong10aCultural evolution10asexual selection10aUrbanization10avocal performance1 aMoseley, Dana, L1 aPhillips, Jennifer, N.1 aDerryberry, Elizabeth, P1 aLuther, David, A.1 aCandolin, Ulrika  uhttps://academic.oup.com/beheco/advance-article/doi/10.1093/beheco/arz142/555110702262nas a2200205   4500008004100000022001400041245009600055210006900151260001600220520156100236653001701797653002101814653002701835653002701862653002101889100002201910700001701932700002101949856008601970       2019                        eng d  a1045-224900aEnvironmental constraints on size-dependent signaling affects mating and rival interactions0 aEnvironmental constraints on sizedependent signaling affects mat  cMar-02-20203 a<p>Advertisement signals can convey information about a sender&rsquo;s characteristics, such as body size. The reliability of signals, however, can be reduced when signal production is partially dependent on the environment. Here, we assess the effect of display-site properties on the production, attractiveness and honesty of sexual signals. We recorded male t&uacute;ngara frogs (Physalaemus pustulosus) while manipulating water levels in order to constrain calling. We found that water level affected male call properties in a size-dependent manner, with call amplitude being less affected in smaller males when forced to call in shallow water. Next, we tested how size-dependent and display-site-dependent signaling affected female choice and rival competition. Both males and females showed the strongest response to the call of a large male when he was calling at the deepest water levels. However, females showed no preference for large over small males when both were recorded in shallow water levels, or, depending on the call rate and timing of calls, even preferred small males. Likewise, males responded equally to large and small rivals recorded calling during shallow water level trials. Our experiments show that display-site properties can influence signal production and attractiveness in a size-dependent manner. These results can have important consequences for the evolution of signaling, as small males may be able to use their size to their advantage when selecting appropriate display sites and thereby outcompete large males.</p>
10adisplay site10ahonest signaling10aPhysalaemus pustulosus10aproduction constraints10asexual selection1 aSmit, Judith, A H1 aLoning, Hugo1 aHalfwerk, Wouter  uhttps://academic.oup.com/beheco/advance-article/doi/10.1093/beheco/arz009/5320523