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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2008.07.027 Byline: Marta B. Manser, Joah R. Madden, Hansjoerg P. Kunc, Sinead English, Tim Clutton-Brock Abstract: In many bird species with biparental care for young in the nest, hungry chicks beg repeatedly and parents adjust their feeding rate to the call rate of young. Repetitive calling also occurs in fledglings and in some mammals where offspring follow provisioners. It is not yet clear whether, in mobile systems with dispersed young where adults cannot compare the vocal behaviour of all young simultaneously, the calls represent a signal of need. We investigated repetitive begging by cooperatively reared meerkat, Suricata suricatta, pups that foraged with the group. Pups produced two types of begging calls: repeat calls over long periods and high-pitched calls mainly confined to feeding events. Food-deprived pups stayed closer to feeders, and begged for longer and more intensely by calling at a higher rate. Hungry pups increased both the rate of repeat calls, which were given continually, and the number of high-pitched bouts, but adults increased their food allocation only in relation to the rate of repeat calls. Our study indicates that hunger may lead to several changes in vocal behaviour, only some of which may be used by adults to assess need. Author Affiliation: (a) Verhaltensbiologie, Zoologisches Institut, Universitat Zurich, Switzerland (a ) Mammal Research Institute, University of Pretoria, South Africa (a ) Department of Zoology, University of Cambridge, U.K. Article History: Received 8 January 2008; Revised 14 March 2008; Accepted 29 July 2008 Article Note: (miscellaneous) MS. number: 08-00015R

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2006.03.022 Byline: Rouven Schmidt, Hansjoerg P. Kunc, Valentin Amrhein, Marc Naguib Abstract: Birdsong is a sexually selected trait that serves in territory defence and mate choice. Individual song traits can be affected by the body condition of the male and thus may reflect his quality. Such relations between male quality and general singing performance raise the question whether differences in male quality also affect response strategies used in dyadic interactions. To address this question, we studied the relation between pairing success of male common nightingales, Luscinia megarhynchos, and their responses to rivals posing different levels of threat. Using interactive playback, we exposed males prior to mating to either aggressively or moderately singing rivals (by song overlapping and song alternating, respectively). Males that remained unpaired throughout the season (bachelors) interrupted their singing significantly more often after being overlapped than after alternating playback, whereas subsequently mated males kept the number of singing interruptions more constant across playback treatment. This suggests that subsequently paired males are less discriminative than are bachelors when challenged by rivals varying in aggressiveness. Regardless of playback treatment, males that later became paired responded significantly more strongly than did bachelor males. Thus, an increase in singing after a vocal interaction prior to mating predicted future mating success. Author Affiliation: (a) Department of Animal Behaviour, Bielefeld University, Germany (a ) Research Station Petite Camargue Alsacienne, University of Basel, Switzerland Article History: Received 2 December 2005; Revised 7 February 2006; Accepted 28 March 2006 Article Note: (miscellaneous) MS. number: 8767

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2005.10.022 Byline: Angelika Poesel, Hansjoerg P. Kunc, Katharina Foerster, Arild Johnsen, Bart Kempenaers Abstract: Sexual selection theory predicts that signals reflecting the relative quality of individuals should be used in mate choice. Females could base their choice of copulation partners on male secondary sexual traits that honestly signal male age, as predicted by the age-based indicator mechanism. Studies have shown that female blue tits prefer older males and that aspects of dawn song reflect male quality, but it remains unknown whether dawn song characteristics correlate with male age. We compared dawn song characteristics of second-year (SY) and older (ASY) male blue tits (cross-sectional analysis), and tested for age-related changes within individuals (longitudinal analysis) and differential overwinter survival of SY males. We further investigated the relation between dawn song and paternity gain and loss. We found that ASY male blue tits began to sing earlier relative to sunrise than did SY males. This difference in the onset of dawn singing was due to age-related changes in individual performance rather than differential survival of individuals with varying expression of the trait. Males that began to sing earlier at dawn had more mating partners, and were more likely to gain extrapair paternity. Our findings suggest that the onset of dawn song can provide a simple mechanism for females to assess the relative quality of their mate and of neighbouring males. We propose that females use the onset of singing as a cue for their choice of extrapair partners. Author Affiliation: (a) Animal Behaviour Group, Biological Institute, University of Copenhagen, Denmark (a ) Department of Animal Behaviour, University of Bielefeld, Germany (a ) Max Planck Institute for Ornithology, Germany (As.) Natural History Museum, University of Oslo, Norway Article History: Received 17 September 2004; Revised 4 December 2004; Accepted 20 October 2005 Article Note: (miscellaneous) MS. number: 8280R

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2005.08.014 Byline: Hansjoerg P. Kunc, Valentin Amrhein, Marc Naguib Abstract: Song overlapping in birds is used and perceived as a signal of aggression, and evidence suggests that eavesdropping females base their extrapair mating decisions on the performance of males in vocal contests. In our study population of nightingales a large proportion of territorial males remain unpaired throughout the breeding season. A comparison between subsequently mated males and unpaired males may reveal whether females could use singing performance during vocal interactions in their choice of a social mate. We investigated how males that differed in their subsequent pairing status overlapped a noninteractive playback during the period of mate attraction, and how males used specific structural song components in response to playback. Subsequently mated males overlapped more playback songs than did males that remained unpaired throughout the breeding season. Males also adjusted the use of specific song components and decreased song rate during playback, suggesting that the flexible use of structural song components is more important in vocal contests than increasing song output. Because song overlapping is thought to be a signal of aggression, more aggressive males seem to have greater pairing success. Author Affiliation: (a) Department of Animal Behaviour, University of Bielefeld, Germany (a ) Research Station Petite Camargue Alsacienne, University of Basel, Switzerland Article History: Received 8 November 2004; Revised 20 January 2005; Accepted 3 August 2005 Article Note: (miscellaneous) MS. number: 8340

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2005.02.010 Byline: Hansjoerg P. Kunc, Valentin Amrhein, Marc Naguib Abstract: Many male temperate zone passerines show a marked peak of singing activity before sunrise. The two main functions of this so-called dawn chorus are mate attraction and territory defence. We examined how seasonal patterns of different dawn song characteristics were related to mating status and to the breeding cycle of females in the common nightingale, Luscinia megarhynchos. We investigated two measures of song output: song rate and percentage performance time. We also calculated the proportion of 'whistle songs', a song category that is thought to be important in female choice. We predicted that if the main function of dawn singing in nightingales is to attract a social mate, then mated males should change their dawn singing behaviour after pair formation. In contrast, if dawn singing is mainly used in territory defence, we expected no difference in song traits between mated and unmated males throughout the season. We found that song rate and the proportion of whistle songs were low at the beginning of the season and did not predict future mating status. After arrival of females, all measures of dawn song performance remained largely constant throughout the breeding season, and we did not find significant differences in the seasonal variation between mated and unmated males. These findings are consistent with the hypothesis that song at dawn is important to defend a territory throughout the breeding season. Author Affiliation: (a) Department of Animal Behaviour, University of Bielefeld, Germany (a ) Research Station Petite Camargue Alsacienne, University of Basel, France Article History: Received 2 February 2004; Revised 5 April 2004; Accepted 20 February 2005 Article Note: (miscellaneous) MS. number: 7989R

Seasonal patterns of singing activity of male birds have been thoroughly studied, but little is known about how those patterns vary with time of day. Here, we censused mated and unmated male Nightingales (Luscinia megarhynchos) at four different hours of the day throughout the breeding cycle. In unmated males, singing activity increased until the young hatched in their neighborhood, and the seasonal variation was similar at each of the four hours of the day. In mated males, however, the seasonal patterns of singing activity differed between hours of the day. In morning (about the hour of egg-laying) and during the dusk chorus, the singing activity of mated males was strongly influenced by the females' reproductive state: singing activity was low before egg-laying and during incubation, but high during the egg-laying period. In the dawn chorus, however, singing activity showed a similar seasonal pattern in mated and unmated males and was high until late stages of the breeding cycle. Our results suggest that the social context influences singing behavior to a varying degree across the season, and that this variation also depends on time of day. The hour of data collection thus is an important but often neglected factor when seasonal changes of singing activity are studied. Received 17 October 2002, accepted 15 September 2003.

Anthropogenically driven environmental changes affect our planet at an unprecedented rate. Among these changes are those in the acoustic environment caused by anthropogenic noise, which can affect both animals and humans. In many species, acoustic communication plays a crucial role to maintain social relationships by exchanging information via acoustic signals. However, how species relying on acoustic communication differ in their adjustments to anthropogenic noise is little understood. Yet, this is crucial because protecting species effectively depends on our capability to predict how species differ in their response to human‐induced environmental changes. Using a phylogenetically controlled meta‐analysis, we quantified differences in adjustments of acoustic signals to anthropogenic noise among species. The effect sizes included in the analysis were obtained from noise exposure experiments, as only carefully controlled experiments allow to establish cause‐and‐effect relationships. We found that animals changed acoustic signals when exposed to noise, but the magnitude and the direction of adjustments differed among species. Given the importance of communication in the animal kingdom, these adjustments can affect social relationships in many species. The diversity of responses among species highlights the necessity to assess the effect of environmental stressors not only for a few species, because an effect may be positive in one species but negative in another depending on the species' biology. Thus, an effective conservation approach to protect different species is to preserve natural soundscapes of ecosystems to which species have adapted to by reducing or mitigating the emission of anthropogenic noise into the environment. [ABSTRACT FROM AUTHOR]

A study on sexual preferences of female blue tits (Cyanistes caeruleus) which is determined by the characteristics of the bird's song and age of male blue tits is discussed.