02390nas a2200229   4500008004100000022001400041245005700055210005600112260001600168520171900184653002601903653002201929653002101951653001801972653001801990653001802008100002202026700001802048700002102066700001802087856005502105       2018                        eng d  a2193-719200aParent-absent begging and the risk of nest predation0 aParentabsent begging and the risk of nest predation  cFeb-11-20203 a<p>Despite the fact that parent-absent begging (PAB) has been studied as a communication tool during competition between nestlings for food or as a signal of need, its role in nest predation has been poorly investigated. In this study we examined whether the natural level of Common Cuckoo (hereafter &ldquo;Cuckoo&rdquo;) PAB increases the risk of artificial nest predation (n&thinsp;=&thinsp;48) by using three types of experimental playback of parent-present begging (PPB) which differ in the presence or absence of additional PPB, PAB or periods of silence. Contrary to our predictions, we did not find a significant difference in daily survival rates between PPB&thinsp;+&thinsp;PAB vs. PPB&thinsp;+&thinsp;PPB nests or between PPB&thinsp;+&thinsp;PAB vs. PPB&thinsp;+&thinsp;silence nests, indicating that the natural level of Cuckoo PAB did not influence nest vulnerability to predation. Moreover, we did not find a significant difference between nests with any of the types of playback and completely silent control nests, suggesting that not only PAB, but also begging behaviour itself, does not present an important predation cost for nestlings, at least not in cases when nestlings beg at the natural level used in our experiment. As we filmed all experimental nests during their exposure to predators, we were able to show that eight of 20 filmed nest-predation events were caused by predators that never or rarely predate upon passerine nests. Excluding predation events by these unlikely predators, however, did not change our original results. Nonetheless, we advocate direct identification of nest predators to strengthen the interpretation of future studies on the predation cost of begging.</p>
10aAcoustic solicitation10aBegging frequency10aBegging loudness10acommon cuckoo10aNest predator10aNest survival1 aJelínek, Václav1 aŠulc, Michal1 aWeidinger, Karel1 aHonza, Marcel  uhttp://link.springer.com/10.1007/s10336-018-1608-202371nas a2200241   4500008004100000022001300041245005800054210005800112260001600170520149800186653002101684653002101705653001801726653002401744653002701768653001901795100001801814700001501832700001601847700001501863700001801878856023301896       2018                        eng d  a0376635700aComponents of variation in female common cuckoo calls0 aComponents of variation in female common cuckoo calls  cJan-10-20183 a<p>Investigations on bird vocalizations have largely focused on males. Female vocalizations are widespread in birds but few studies have investigated female vocal characteristics, particularly in non-Passeriformes. In this study, we use new field recordings from China, and calls available from an online sound library to examine temporal patterns, call consistency and geographical variation in vocalizations of female common cuckoos Cuculus canorous. The peak in vocal activity (both male and female) was in the morning, which contrasts to what would be predicted if the sole function of the female call was to distract the attention of hosts after parasitizing a host&rsquo;s nest in the afternoon. Both male and female common cuckoos were more vocally active in sunny weather, than rainy weather. We also found larger intra-individual variation in female rather than in male calls, which may benefit female cuckoos by increasing stimulation to host species. Peak frequency of female calls decreased with increased latitude, while differences in female call features were not associated with geographic distance. In summary, our findings that female calls are used in the morning, rather than at peak egg laying, yet are highly variable and show little geographic patterns suggest that the function of these female calls may be more variable and intricate than previously thought. However, because research on female vocalizations is underrepresented, future studies are still needed.</p>
10aacoustic signals10acall consistency10acommon cuckoo10afemale vocalization10ageographical variation10avocal activity1 aDeng, Zhuqing1 aLloyd, Huw1 aXia, Canwei1 aLiang, Wei1 aZhang, Yanyun  uhttps://linkinghub.elsevier.com/retrieve/pii/S0376635718302997https://api.elsevier.com/content/article/PII:S0376635718302997?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0376635718302997?httpAccept=text/plain