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Copyright of Huitzil: Journal of Mexican Ornithology / Revue d'Ornithologie Mexicaine is the property of Sociedad para el Estudio y Conservacion de las Aves en Mexico and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2008.03.025 Byline: Timothy F. Wright, Christine R. Dahlin, Alejandro Salinas-Melgoza Abstract: Cultural evolution is an important force in creating and maintaining behavioural variation in some species. Vocal dialects have provided a useful model for the study of cultural evolution and its interactions with genetic evolution. This study examined the acoustic and geographical changes in vocal dialects over an 11-year span in the yellow-naped amazon, Amazona auropalliata, in Costa Rica. Contact calls were recorded at 16 communal night roosts in 1994 and 19 roosts in 2005, with 12 of the roosts sampled in both surveys. In both surveys, three dialects were found, each characterized by a distinctive contact call type and each encompassing multiple roosts. The limits between two of these dialects, the North and South dialects, was found to be geographically stable, while at the boundary between the North and Nicaraguan dialect there was introgression of each call type into roosts in the bordering dialect. Acoustic measurements and cross-correlations of spectrograms detected no change in the acoustic structure of contact calls in the South dialect but did show significant differences in the calls of both the North and Nicaraguan dialect between 1994 and 2005. These results are consistent with the vocal convergence hypothesis, which proposes that dialects are long-term features maintained through some combination of biased transmission of local call types and purifying selection against foreign call types. Migration, copying errors and cultural drift may also play a role in the more subtle changes seen in the acoustic form of dialect call types. Author Affiliation: Department of Biology, New Mexico State University Article History: Received 17 December 2007; Revised 3 February 2008; Accepted 27 March 2008 Article Note: (miscellaneous) MS. number: A07-20030

For 1996--2003, we determined reproductive output and success of 70 Lilac-crowned Parrot (Amazona finschi) nests in tropical dry forest of the Chamela-Cuixmala Biosphere Reserve in western Mexico. Only 42% of nests had young that fledged; predation was the main cause of nest failure. Low brood survival in 2000 and 2003 caused significant between-year variation in the probability of nest success during the nestling phase of the nest cycle. Reproductive output of Lilac-crowned Parrots was low, with females producing an average of 0.99 fledglings on an initial investment of 2.6 eggs. The fecundity component of clutch size varied significantly between years, because of the high median clutch size recorded in 2000. Nestling survival also varied significantly between years, creating large interannual fluctuations in reproductive output. The most productive breeding season was 1999, with an average output of 1.7 fledglings on an investment of 2.7 eggs; whereas the poorest breeding season was 2000, with an output of 0.57 fledglings from 3.3 eggs. Loss of reproductive potential was greatest in 2000 and 2003, because of brood reduction through starvation of later-hatched nestlings, with hatching order influencing the probability of nestling survival. Mean number of nestlings per egg-laying female was associated with interannual fluctuations in precipitation resulting from the El Nino-La Nina weather cycle in the Pacific Ocean. Both nest predation and food availability may limit parrot reproduction in tropical dry forests, with populations of threatened species in dry habitats being vulnerable to effects of climatic variability and habitat fragmentation. Received 4 September 2003, accepted 24 June 2004.

Geographic variation in acoustic signals may arise in vocal learning species due to processes of cultural evolution and population dynamics, but few studies have evaluated geographic vocal variation for large-bodied non-oscine species such as parrots. We evaluated similarity in a contact call of the Military Macaw (Ara militaris) among three populations along the coast of Jalisco, Mexico. We compared contact calls among sites using two approaches i) analysis of specific acoustic parameter measures using GLMM on Principal Components; and ii) evaluation of spectrogram similarity using cross-correlation with a Mantel test to evaluate site and distance effects. Acoustic parameter analysis found that incorporating the site where recordings were obtained significantly explained variation in call features, for both the complete and reduced, balanced dataset. The spectrogram cross-correlations similarity analysis indicated an association with site in spectral similarity of calls, and that call similarity decreased with distance. Our results demonstrated the accumulation of small, fine-scale changes in Military Macaw calls with distance, suggesting that large-bodied non-oscines such as macaws may be able to maintain connectivity among sites by dispersal, facilitating call diffusion, while limited movements among some populations may account for the differentiation among sites in call features. [ABSTRACT FROM AUTHOR]

The survival and development of juvenile lilac-crowned parrot (Amazona finschi) fledgling during their first year after leaving the nest are determined. Overall first year survival was found to be 73% with all mortalities occurred within 3 weeks of fledging and highest mortality in the first week postfledging, and survival was found to vary between years, thus influencing recruitment of independent young in the population.