Search

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2009.05.024 Byline: Jesse M.S. Ellis (a)(b), Tom A. Langen (c), Elena C. Berg (d) Abstract: Food begging is common in nutritionally dependent young of many animals, but structurally homologous calls recur in adult signal repertoires of many species. We propose eight functional hypotheses for begging in adults; these stem from observations in birds but apply broadly to other taxa in which begging occurs. Adult cooperatively breeding white-throated magpie-jays, Calocitta formosa, use loud begging vocalizations, particularly near the nest site during reproduction. We analysed the social context and behavioural phenology of loud calling and allofeeding in this species and compared these with predictions from each functional hypothesis. We found that reproductive females were the primary producers of beg calls, and their begging peaked during the fertile period when reproductive conflict among males and females was highest. Loud begging rates correlated positively with provisioning rates, but females called more in the pre-incubation fertile period than they did after they had initiated incubation. Based on the context, phenology and active space of the signal, we conclude that female loud begging vocalizations function to signal nutritional need to group members, but also have been evolutionarily co-opted to advertise fertility to potential extrapair partners. The location of calling is probably a consequence of nest guarding by breeding females to prevent intraspecific brood parasitism. Author Affiliation: (a) Laboratory of Ornithology, Cornell University, U.S.A. (b) Department of Neurobiology and Behavior, Cornell University, U.S.A. (c) Department of Biology, Clarkson University, U.S.A. (d) Department of Biology, Portland State University, U.S.A. Article History: Received 10 October 2008; Revised 7 January 2009; Accepted 18 May 2009 Article Note: (miscellaneous) MS. number: A08-00662

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2009.02.017 Byline: Charlotte Roy (a), John M. Eadie (b), Eric M. Schauber (a), Nicole S. Odell (b), Elena C. Berg (b), Thomas Moore (b) Abstract: When nest fates are correlated among years, individuals may use information on the success of conspecifics (public information) to evaluate the relative quality of nest sites. In wood ducks, Aix sponsa, conspecific nest parasitism can reduce success at a nest site, especially at high nesting densities. Therefore, parasitism may influence the correlation of nest fates among years, as well as the quality and use of information. We examined the use of public information by wood ducks in four populations nesting in nestboxes placed at high (18-40 boxes/km) and low densities (5-9 boxes/km) along streams. Nest success was negatively related to density, but previous success did not consistently predict future success. Nests failed most frequently as a result of desertion, which was associated with nest parasitism. Nestbox use was higher for previously used boxes and at high-density sites. Clutch size, which we used as an index of parasitism, was higher in previously unsuccessful nests and was positively related to nestbox density. Thus, at high nestbox densities, nests that were abandoned, perhaps in response to parasitism, were also parasitized the following year and met with mixed success. Likewise, successful nest sites were not necessarily successful the following year. These findings might explain why wood ducks do not select nestboxes based on conspecific success. Contrary to results published for other cavity-nesting species, current success did not provide information about future success at sites with high densities of nestboxes. Author Affiliation: (a) Cooperative Wildlife Research Laboratory, Southern Illinois University, Carbondale, IL, U.S.A. (b) Wildlife, Fish, and Conservation Biology, University of California, Davis, CA, U.S.A. Article History: Received 9 June 2008; Revised 13 October 2008; Accepted 4 February 2009 Article Note: (miscellaneous) MS. number: A08-00387R

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2004.11.008 Byline: Elena C. Berg Abstract: I conducted a 3-year study investigating parentage in a Costa Rican population of white-throated magpie-jays, a cooperatively breeding corvid inhabiting the tropical dry forests of Central America. This species is unusual among avian cooperative breeders in that helpers are mostly females. Using 12 microsatellite loci, I estimated parentage for 110 offspring in 32 broods and eight social groups. Primary breeders were not the sole producers of offspring within a brood. At the 95% confidence level, female helpers within the group produced 16% of young, and floater males sired approximately 30% of young. Helpers that bred mated either with the primary male (three cases) or with floaters (five cases). When the analysis was limited to the most reliable data, the 20 nests and 63 offspring where all candidate mothers had been sampled, at the 95% confidence level only one helper produced young, while floater males sired 22% of offspring. The results of this study cast doubt on the simple classification of white-throated magpie-jays as cooperative breeders and suggest a more complex combination of cooperative and parasitic behaviours. Author Affiliation: Center for Animal Behavior, University of California at Davis, U.S.A. Article History: Received 9 July 2004; Revised 18 September 2004; Accepted 2 November 2004 Article Note: (miscellaneous) MS. number: A9934R

A study was conducted to investigate parentage in a Costa-Rican population of white-throated magpie-jays, a co-operative breeder in the tropical dry forest of Central America. The results showed that a more complex combination of co-operative and parasitic behaviors were suggested instead of simple classification of white-throated magpie-jays, as co-operative breeders.