02109nas a2200253 4500008004100000022001400041245006900055210006500124260001600189520134000205653002301545653001201568653003001580653001301610653001501623653000901638100002201647700002201669700002301691700003101714700003101745700002401776856005501800 2018 eng d a2193-719200aThe buzz segment of Savannah sparrow song is a population marker0 abuzz segment of Savannah sparrow song is a population marker cMar-12-20183 a

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.

10aCultural evolution10adialect10aPasserculus sandwichensis10aplayback10aPopulation10asong1 aWilliams, Heather1 aRobins, Clint, W.1 aNewman, Amy, E. M.1 aFreeman-Gallant, Corey, R.1 aWheelwright, Nathaniel, T.1 aMennill, Daniel, J. uhttp://link.springer.com/10.1007/s10336-018-1611-702742nas a2200241 4500008004100000022001300041245012300054210006900177260001600246300001400262490000800276520181500284653001802099653002502117653002202142653002002164653001202184653002402196653001302220100001802233700001602251856023302267 2018 eng d a0003347200aSocial context-dependent provisioning rules in red-winged fairy-wrens do not vary with signals of increased chick need0 aSocial contextdependent provisioning rules in redwinged fairywre cJan-09-2018 a105 - 1110 v1433 a

Individuals should adjust investment in parental care in order to maximize current and future reproductive success. In cooperative breeders, where helpers assist with raising offspring, larger groups may allow for a reduction in investment (load lightening) of each individual. Additionally, the type of individual, and thus the social context, can play an important role in individual investment. Less attention has been paid to how provisioning rules vary across ecological contexts, although theory suggests that individuals can only afford to reduce their investment when nestling starvation is unlikely, thus under mild conditions. Here, we tested whether previously reported provisioning rules based on social context vary with ecological conditions, by experimental manipulation of signals of chick need, in the cooperatively breeding red-winged fairy-wren, Malurus elegans. Previous work in this species has shown that all group members load-lighten with additional male helpers, but not in response to the number of female helpers in the group (additive care). We show that experimental begging playback resulted in all individuals increasing their provisioning rates, indicating that our treatment was perceived as increased chick need. However, in contrast to our prediction that load lightening should only occur when individuals can afford to do so, signals of increased chick need did not stop individuals from reducing their investment with an increasing number of male helpers in the group. These results suggest that despite some flexibility in parental effort, individuals use strict rules with respect to group composition, suggesting that individual provisioning effort is based on multiple integrated cues, and responses to changes in the environment are highly context dependent.

10aadditive care10acooperative breeding10ahelping behaviour10aload lightening10aMalurus10aparental investment10aplayback1 aMacLeod, K.J.1 aBrouwer, L. uhttps://linkinghub.elsevier.com/retrieve/pii/S0003347218302252https://api.elsevier.com/content/article/PII:S0003347218302252?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0003347218302252?httpAccept=text/plain02808nas a2200265 4500008004100000022001300041245012500054210006900179260001600248300001100264490000800275520179900283653002202082653001802104653001302122653002202135653002402157653001502181100002402196700002002220700002302240700002102263700002502284856023302309 2018 eng d a0003347200aSubspecies status and methods explain strength of response to local versus foreign song by oscine birds in meta-analysis0 aSubspecies status and methods explain strength of response to lo cJan-08-2018 a1 - 170 v1423 a

To understand the implications of geographical variation in vocal culture in songbirds, researchers have often compared territorial responses to playback of local songs versus responses to playback of songs from ‘foreign’ conspecifics. This body of work has the potential to help us move towards a general understanding of factors driving divergence in signal recognition. We conducted a systematic review and meta-analysis of 57 playback studies to explain variation in strength of response to local versus foreign songs. Studies with incomplete reporting of results had elevated effects due to selective reporting. Studies that used small numbers of stimuli as exemplars (pseudoreplication) had more variable effects than studies without severe pseudoreplication. Whether or not we controlled for pseudoreplication, we found greater response to playback of local song than to foreign song. In investigating potential biological drivers of the variation in strength of experimental effects, we found that the difference in territorial response to local versus foreign song was stronger if the foreign song was recorded from another subspecies than if the foreign song was recorded from the same subspecies as the focal individuals. Indexes of risk of accidental response to heterospecific song did not coherently explain response to foreign conspecific songs, nor did factors expected to influence individual experience with foreign conspecific songs. Thus, although oscine songbirds clearly react more aggressively to local song than to foreign song and variation in the strength of this effect is influenced by methodological choices and subspecies status, considerable variation in the strength of response to local versus foreign song playback remains to be explained.

10adeceptive mimicry10ameta-analysis10aplayback10apseudoreplication10aselective reporting10asignalling1 aParker, Timothy, H.1 aGreig, Emma, I.1 aNakagawa, Shinichi1 aParra, Marcelina1 aDalisio, Anthony, C. uhttps://linkinghub.elsevier.com/retrieve/pii/S000334721830174Xhttps://api.elsevier.com/content/article/PII:S000334721830174X?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S000334721830174X?httpAccept=text/plain