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In this thesis, I analysed the mating behaviour of the solitary-nesting American kestrel (Falco sparverius) in southern Quebec (Canada) and the colony-nesting lesser kestrel (F. naumanni) in Aragon (Spain). DNA fingerprinting of 26 families of lesser kestrels revealed that 3.4% of nestlings were extra-pair, which may have arisen through either extra-pair copulation or mate replacement. Two nestlings in two different nests were also the result of intraspecific brood parasitism. DNA fingerprinting of 21 American kestrel families showed that all the nestlings in two nests were extra-pair (10% extra-pair young overall), most probably due to mate replacement. / I analysed the mating behaviour of both species in two studies with a similar aim, i.e. to test why mated pairs copulate so frequently. Sixteen pairs of wild American kestrels and 12 pairs of "solitary" lesser kestrels (14 nests per 0.3 km$ sp2)$ were analysed in terms of four hypotheses that explain high frequency of within-pair copulations both outside and during the fertile period. First the Paternity Assurance Hypothesis, i.e. males control timing and frequency of copulations to best assure fertilization, was rejected because extra-pair copulation attempts were low in both species ($<$1% of all copulations observed), within-pair copulation frequencies did not increase with nest density in the lesser kestrel, and copulation and mate attendance did not increase as the fertile period approached. Second, the Immediate Material Benefits Hypothesis, i.e. females trade copulations for food, was refuted because copulation most often occurred without food transfers. Third, the Female Mate-Guarding of Males Hypothesis, i.e. females distract their mates from other mating opportunities by copulating frequently, was rejected because male loss was low, males and females solicited similar amounts of copulations, and females did not differ in the timing or frequency of solicitations. Finally, the Mate Assessment Hypothesis, i.e. assessment of mate quality is mediated by copulation, most closely predicted the behaviour observed since within-pair copulation was high outside the fertile period and during pair formation in both species.

Nest box programs provide supplemental nest sites for American Kestrels, Falco sparverius. When the availability of nest sites is a limiting factor, the addition of nest boxes can increase local breeding populations. These programs also facilitate the collection of data on breeding kestrels. This study focuses on an American Kestrel (Falco sparverius) nest box trail along Interstate 26 in northeastern Tennessee during the breeding seasons of 1998, 1999, 2000, 2003, 2004, 2006, and 2009. Productivity measures and reproductive success of nesting birds are provided and compared to other programs. The data are analyzed across years and by box. Finally, a discussion of the habitat surrounding the most and least active boxes provides recommendations for increased efficiency of the program.

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American Kestrels (Falco sparverius) are a small falcon with an expansive range across North America. However, kestrels have been reported to be declining since the 1960s, with the primary cause of decline unknown. With previous research focusing on the summer breeding season, researchers have called for additional investigation in understudied wintering and migratory periods. In Chapter 2, I quantified annual survivorship against five covariates of migrant kestrels wintering in north Texas to contribute to population level analyses across the kestrel's expansive range. Notably, I found that juvenile survival is similar to that of adults once on the wintering grounds, and that aspects of urbanization may increase survival in wintering kestrels. In Chapter 3, I outlined kestrel movement ecology by quantifying migration phenology, performance, and patterns. Additionally, I identified breeding and stopover sites and analyzed both winter and summer home ranges. In this analysis, I contributed three additional migration tracks to the five currently published. Further, I reported the first loop and indirect migration patterns to our knowledge. Overall, this research highlights understudied aspects of the kestrel full annual cycle in the winter and migratory periods, providing insight into possible causes for kestrel declines.

Made available in DSpace on 2014-06-11T19:35:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-07-22Bitstream added on 2014-06-13T18:46:32Z : No. of bitstreams: 1 pereira_rjg_dr_jabo.pdf: 242711 bytes, checksum: 723f7381e49b4cd2159897db271a8b96 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Apesar da radiotelemetria ser considerada uma ferramenta valiosa em estudos ornitológicos, algumas teorias relativas ao impacto de radiotransmissores sobre a estimativa de parâmetros comportamentais, ecológicos e reprodutivos podem ser encontradas em literatura. Com o intuito de avaliar os potenciais efeitos fisiológicos de radiotransmissores do tipo mochila em falcões quiri-quiri (Falco sparverius) de vida livre, oito machos desta espécie foram capturados e divididos em dois grupos: indivíduos marcados com radiotransmissores (aproximadamente 5% do peso vivo, n = 6) e indivíduos controle (anilhados, n = 2). Em seguida, amostras fecais foram coletadas duas horas após a captura (dia −1) e durante os dias 0 (definido como o dia de soltura dos animais), 4, 7, 15, 30, 40 e 55. Previamente às análises laboratoriais, o ensaio imunoenzimático para dosagem de glucocorticóides fecais foi testado empregando procedimentos padrões de validação hormonal (paralelismo, curva de dose-resposta, validação fisiológica e coeficientes de variação inter- e intra-ensaio). Em relação aos machos monitorados, ambos os grupos apresentaram um aumento significativo nos níveis de glucocorticóides fecais durante o dia 0 (P < 0,001), mas as concentrações retornaram aos níveis pré-equipagem após 4 dias da soltura. Além disso, os níveis de glucocorticóides fecais não diferiram significativamente entre os falcões radiomarcados e os anilhados durante os 55 dias de monitoramento (P > 0,05). Embora o número de indivíduos neste estudo seja reduzido, estes resultados sugerem que radiotransmissores do tipo mochila não induzem efeitos persistentes sobre a atividade adrenal de machos de falcões quiri-quiri de vida livre. Considerando a literatura consultada, esta é a primeira pesquisa a analisar os efeitos de radiotransmissores sobre a resposta adrecortical de aves de vida livre. / Although radiotelemetry is considered a valuable technique for ornithological field studies, several assumptions have been made about the impact that transmitters may cause on the estimation of behavioral, ecological and reproductive parameters. To assess potential effects of backpack radiotransmitters, we captured and assigned 8 male American kestrels (Falco sparverius) in 2 groups: radio-tagged (n = 6) and control individuals (leg-banded, n = 2). Thereafter, we collected feces two hr after capture (day −1), and subsequently during days 0 (releasing day), 1, 4, 7, 15, 30, 40 and 55. Prior to fecal analysis, EIA corticosterone assay was validated using standard procedures (e.g. parallelism, dose-response curve), and physiological significance of fecal glucocorticoid metabolites was confirmed through adrenocorticotropin (ACTH) challenge, which induce an increase of 4-fold (446.10 ± 60.73 ng/ g) above baseline (114.27 ± 15.23 ng/ g) within 4 hr (P < 0.001). Both groups exhibited a significant increase in fecal glucocorticoids during day 0 (P < 0.001), but concentrations returned to pre-attachment values within 4 days. Fecal glucocorticoid concentrations did not differ between samples of radio-tagged and leg-banded kestrels (P > 0.05). In spite of the small number of monitored subjects, these findings suggested that radiotransmitters did not affect adrenocortical activity in male American kestrel. To our knowledge, this is the first research to evaluate the effects of transmitters on stress responses in free-ranging birds.