Thesis (Ph.D.) - James Cook University, 2004. / Typescript (photocopy). Bibliography: leaves 105-134.

Thesis (Ph. D.)--University of North Texas, 2002. / Title from PDF title page (viewed on Dec. 9, 2004). Includes bibliographical references (p. 350-356).

Roseate spoonbills are colonial nesting birds with breeding grounds extending from the United States Gulf coast to the pampas of Argentina. The U.S. population suffered a severe bottleneck from 1890 to 1920. The population's recovery was slow and partially credited to migrations from Mexican rookeries, but a gene pool reduction would be expected. Five polymorphic Spoonbill autosomal short tandem repeat (STR) loci [three (GAT)n, one (AAAG)n and one (GT)n] and one Z/W-linked microsatellite exhibiting sex-specific dimorphism were isolated and characterized. The Z/W-linked STR locus accurately confirmed the sex of each bird. Allelic profiles for 51 spoonbills obtained from Dallas (Texas), Fort Worth (Texas) and Sedgwick County (Kansas) zoos revealed a non-continuous distribution of allele frequencies, consistent with the effects of a population bottleneck. Allelic frequencies also differed significantly between the isolated zoo populations. Although extra-pair copulations were suspected and difficult to document, zoos commonly used observational studies of mating pairs to determine familial relationships among adults and offspring. STR parentage analysis of recorded family relationships excluded one or both parents in 10/25 cases studied and it was further possible to identify alternative likely parents in each case. Mistaken familial relationships quickly lead to the loss of genetic variability in captive populations. Here, a decreased heterozygosity (HO) in 2nd generation captive-bred birds was observed at 3 out of 4 loci evaluated. Although these results could not be statistically validated because of the small number of individuals available for study (15 wild birds with no offspring vs. eight 2nd generation captive birds), they are considered biologically important, as decreased HO is an indicator of inbreeding and this apparent decrease occurred within two generations of removal from the wild. Collectively, the evidence obtained from this study suggests that captive spoonbill populations are experiencing rapid loss of diversity from an already depleted wild gene pool.

The study that I detail in the following thesis is a component of a three-part collaborative project to provide the U. S. National Park Service and Cape Cod National Seashore (CCNS) with data needed to inform management decisions for protection of the endangered northwest Atlantic Roseate Tern (ROST) during fall pre-migratory staging. This study was designed to address objectives related to hatch-year (HY) ROST behavior and survival in response to human and non-human activities and environmental variables at CCNS. Behavioral data showed that disturbance, specifically human and non-human activities, were related to increased HY ROST locomotion (flying and walking). We also found that environmental variables, including day of season and time of day were related to increased locomotion. Flock-level HY ROST begging behavior was decreased in the presence of human disturbance, but we did not see the same effect at the individual level. We found no evidence that the observed behavioral effect of disturbance resulted in decreased residency, recruitment, or staging duration of HY ROST at CCNS. Our work demonstrates that disturbance events around staging flocks have behavioral consequences, but it is unknown whether HY ROST behavioral responses to disturbances are great enough to impact survival after departure from CCNS. A conservative and proactive management strategy to minimize the potential for negative carryover effects on survival should limit ROST exposure to disturbance, particularly human activities, by exclosing staging sites between mid-July–mid-September to encompass the period of time when the highest number of ROST use CCNS. / Master of Science / The study that I detail in the following thesis is one component of a three-part collaborative project to inform management decisions for protection and recovery of the endangered northwest Atlantic Roseate Tern (ROST) population while they prepare for southward migration at Cape Cod National Seashore, MA (CCNS). This study was designed to address objectives related to hatch-year (i.e., HY, birds that were just hatched on the breeding grounds and now flying south for the first time) ROST behavior and survival in response to human and non-human activities and environmental variables at CCNS. We found that disturbance, specifically human and nonhuman activities were associated with increased locomotion (walking and flying). We also found that certain environmental variables, including day of season and time of day were related to increased locomotion rates. Additionally, proportions of HY ROST within a flock that engaged in begging behavior decreased in the presence of human disturbance, but we did not see the same effect at the individual level. We found no evidence that the observed behavioral effect of disturbance resulted in decreased residency, or time spent at CCNS by HY ROST. Our work demonstrated that human activity around tern flocks had behavioral consequences, but it is unknown whether HY ROST behavioral response to human disturbances was great enough to impact survival after departure from CCNS staging grounds. A risk-averse management strategy would entail limiting ROST exposure to potential human disturbance by closing off staging sites between mid-July–mid-September to human activity to encompass the period of time when the highest number of ROST use CCNS.

An erosion control revetment was constructed at the Falkner Island Unit of the Stewart B. McKinney National Wildlife Refuge, Connecticut during the winter of 2000–2001. At the time, Falkner Island was the fifth largest breeding colony site for the federally endangered Roseate Tern. This study measures and describes some baseline information regarding Roseate Tern nesting, behavior, and habitat use at Falkner Island during the three breeding seasons prior to revetment construction (1998–2000). This baseline information is then compared to similar information from the first breeding season following revetment construction (2001). For Roseate Tern adults, this study examined changes in pre-nesting habitat use, nest site distributions, and pre-nesting behavioral time allocation. Changes in habitat availability and habitat use by Roseate Terns are compared as a result of the revetment construction. Roseate Terns used rocky beach in a greater proportion than other habitats before revetment construction, and used revetment boulders in a greater proportion than all other habitats after revetment construction. Roseate Terns nested more often in artificial sites (nest boxes and tires) than in natural sites in all years of the study. The mean date for the first eggs in each nest did not differ between years. We observed more Roseate Terns prospecting artificial nest sites (n = 66 times) than natural sites (n = 21 times) for three years of this study. Prospecting behavior occurred later in the season in some subcolonies, but this difference did not appear to be related to the construction. For Roseate Tern chicks, this study investigated the use of crevices as hiding places from before (1999–2000) and after (2001) the construction of an erosion control revetment. In all years, Roseate Tern chicks used crevices found under artificial nest sites more frequently than expected by chance when compared to crevices found in other microhabitats. Chicks also used crevices formed in various microhabitat types at different stages of development. The erosion control revetment created crevices that had larger openings, steeper floors, and deeper lengths than those previously used by chicks before construction. In the year after revetment construction, the openings of crevices used by chicks that died were wider than crevices used by chicks that survived. We discuss our findings in the context of the potential consequences that the revetment construction had on Roseate Tern chick survival.

Made available in DSpace on 2016-06-02T20:20:30Z (GMT). No. of bitstreams: 1 3280.pdf: 5102569 bytes, checksum: f511b08e43998ea79e0f9b0ac5ed969b (MD5) Previous issue date: 2010-08-06 / Universidade Federal de Sao Carlos / Population genetic parameters and genetic relatedness estimates were carried out for Roseate Spoonbill (Platalea ajaja), Wood Stork (Mycteria americana) and Great Egret (Ardea alba egretta) reproductive colonies in Amapa, Pantanal and Rio Grande do Sul (RS), Brazil. Microsatellite genotypes were used to investigate kinship patterns between nestlings sampled inside the same nests, using a variety of analytical approaches. Unrelated nestling-pairs were observed in Roseate Spoonbill nests (6.12% of analyzed nests) and in Wood Stork nests (11.34%); half-siblings were present in Roseate Spoonbill nests as well (1.36%). Only full-siblings were detected inside Great Egret nests. Conspecific brood parasitism (CBP) and extra-pair paternity were proposed to account for the presence of unrelated nestmates and half-siblings, respectively, in Roseate Spoonbill and Wood Stork nests. Those results suggest the occurrence of a mating system different than genetic monogamy in natural populations of those waterbirds. Genetic relatedness was also investigated for adults and offspring, as well as for supposed siblings in Roseate Spoonbill families kept in three zoological facilities in the U.S. Paternity and maternity allocation analyses through maximum-likelihood revealed that errors were present in zoo‟s studbooks in relation to the familial records. We also identified mating between related individuals that were not detected previously by zookeepers. Population genetic parameters were also estimated and demographic processes were assessed for Great Egret reproductive colonies in the Pantanal and Rio Grande do Su, Brazil. Bayesian clustering analyses, assignment tests, analysis of molecular variance, F-statistics estimates, allelic frequency distribution and the G-W index revealed that: i) Pantanal reproductive colonies are genetically differentiated from Rio Grande do Sul colonies; ii) an IBD-like pattern alone cannot explain that differentiation; and iii) genetic signal of a reduction of population size was present for two colonies in the Pantanal and one in Rio Grande do Sul. Results were discussed considering a metapopulation dynamic and also considering that populations from both Brazilian regions represent distinct units and deserve to be treated separately when planning and carrying out conservation and management programs that aim to preserve the species‟ genetic diversity. / Estudos de genética de populações e de parentesco genético foram desenvolvidos em colhereiro (Platalea ajaja), cabeça-seca (Mycteria americana) e garça-branca-grande (Ardea alba egretta), de colônias reprodutivas do Amapá, Pantanal e Rio Grande do Sul (RS), Brasil. Genótipos em locos de microssatélites foram utilizados para se investigar os padrões de relacionamento entre ninhegos amostrados dentro dos mesmos ninhos com diferentes metodologias de análise. Pares de ninhegos não-relacionados foram encontrados nos ninhos de colhereiro (6,12% dos pares analisados) e de cabeça-seca (11,34%); meio-irmãos foram observados nos ninhos de colhereiro (1,36%). Em garça branca grande foi detectada apenas a presença de irmãos-completos dentro dos ninhos. Parasitismo de ninho intraespecífico e paternidade extra-par podem explicar a presença de ninhegos não-relacionados e meio-irmãos nos ninhos de colhereiro e cabeça-seca, o que indica a presença de um sistema de acasalamento diferente da monogamia genética nas populações naturais dessas espécies. Relações de parentesco entre adultos e filhotes e entre supostos irmãos foram determinadas em famílias de colhereiro de três zoológicos dos EUA. Análises de atribuição de maternidade e paternidade por máxima verossimilhança revelaram erros nos registros dos zoológicos quanto às relações progenitor-progênie e identificaram acasalamentos entre indivíduos aparentados que não tinham sido registrados. Parâmetros genético-populacionais e processos demográficos foram investigados em populações de garça-branca-grande do Pantanal e do Rio Grande do Sul. Análises Bayesianas, testes de alocação de indivíduos, análises de variância molecular, estimativa de estatísticas F, exame da distribuição das freqüências alélicas e cálculo do índice de G-W permitiram identificar que: i) há diferenciação genética significativa entre colônias reprodutivas do Pantanal e do Rio Grande do Sul; ii) o padrão de isolamento pela distância não explica essa diferenciação; e iii) duas populações no Pantanal e uma população no RS apresentaram sinais genéticos de redução demográfica. Os resultados foram discutidos considerando que as populações de garça-branca-grande localizadas no Pantanal e no Rio Grande do Sul são unidades populacionais independentes e devem se tratar separadamente no planejamento e desenvolvimento de programas de manejo para a conservação da diversidade genética total da espécie.