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Nest predation can significantly reduce hatchling recruitment in sea turtle populations. This study uses 20 years of data from Canaveral National Seashore, Florida, which has pristine and altered beaches. Chi-square tests were used to determine if secondary predation events were related to the nest's primary depredation event. To determine if human beach use and nest predation are spatially or temporally linked, we ranked human beach use and examined predation frequency across all screened and marked nests (n=40,441). Lastly, I quantified nest predation risk spatially and temporally. I found that primary predation increases the chance of a nest suffering subsequent predation. Primary and multiple predation events occurred with greater frequency in limited use areas and with lowest frequency in moderate use areas. Predation risk decreased by an average of 29.5% from 2000-2008. Nests deposited midseason were 9.8% more likely to be predated than nests deposited early or late. / by Rachel Welicky. / Thesis (M.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

Canada’s boreal forest provides important breeding habitat for 12 to 14 million migratory birds annually. Nonetheless the ecology of boreal wetlands remains poorly understood. Over the last 40 years, rapid industrial development with little attention to conservation has been ongoing in the region. Apparent population declines of species, such as that of lesser scaup have raised concerns about the quality of western boreal wetlands. This is one of very few studies demonstrating patterns in brood-rearing habitat use by ducks and grebes in the Canadian western boreal forest. In this study, wetland characteristics associated with brood-rearing wetlands of American wigeon (Anas Americana), green-winged teal (Anas crecca), mallard (Anas platyrhynchos), lesser scaup (Aythya affinis), ring-necked duck (Aythya collaris), horned grebe (Pondiceps auritus), and red-necked grebe (Podiceps grisegena) were investigated on 75 wetlands near Yellowknife, NT, Canada. I used Principle Components and regression analyses to delineate patterns of habitat use by breeding water birds. Results indicate that physical characteristics of wetlands, area in particular, had stronger correlations with brood-rearing habitat then did invertebrate abundance. Invertebrate groups positively associated with brood-rearing wetlands included: Amphipoda, Pelecypoda, and or Ephemeroptera. Breeding diving ducks had negative iv associations with Dipteran abundance. Diving ducks and red-necked grebes were more strongly correlated with habitat variables then were dabbling ducks and horned grebes. Brood-rearing wetlands of the smallest birds in the study, green-winged teal and horned grebe, had the fewest and weakest associations with habitat variables. / xiii, 97 leaves ; 29 cm

The gray partridge (Perdix perdix) is a bird species living in hiding and nesting on the ground in the open landscape. Even though this species uses several well-known anti-predator adaptations and strategies, its nests are often predated. The range of nest predators and the circumstances of predation have not, however, been satisfactorily described yet. This diploma thesis summarizes the results of experiments carried out on artificial nests and is supplemented by the description of nest behaviour of two incubing hens obtained from video shooting their nests. This work also includes the results of video shoots of predators on artificial nests, the most common of them being the marten. The successful survival of nests in all experiments was influenced mainly by hiding the nest in vegetation. However, the presence of feather odour of adult birds increased the risks of predation even for well-hidden nests. Nests placed in grass biotopes survived the best regardless their covering. What mattered most in other biotopes (along the edges of field roads, forests or groves and field biotopes off any lines) was the covering of nests with vegetation. Partridges nesting close to the edge of a forest or a grove are not very safe from predators. The fact that both nesting partridges and nest predators prefer a...

Introduced species present one of the greatest threats to biodiversity of native species, and knowledge of introduced species ecology is imperative for the development of management plans to ensure conservation of native species populations. We sought to determine the distribution and nesting behavior of an introduced population of red-bellied squirrels (Sciurus aureogaster) on islands of the Florida Keys currently managed as part of Biscayne National Park, and document potential for the species to impact native flora and fauna. Squirrels were difficult to observe in the dense vegetation of the subtropical forest, so we relied on their leaf nests, which were highly visible in the canopy of trees, to determine current presence and distribution on the Park's islands. We found nests throughout the mixed-hardwood forests of Elliott Key and Sands Key, and also documented a single, old nest on Old Rhodes Key, the first ever documentation of the species that far south in the Upper Keys. Nests were located in tall trees with more canopy linkages than random focal trees, and nests were placed in the upper canopy on the north side of the nest tree more often than expected by chance. Squirrels selected West Indies mahogany (Swietenia mahagoni) to place nests more often than available in the forest. Squirrels used areas with greater tree density and canopy cover, but lower recent hurricane damage and fewer woody shrub stems, than areas available at random in the forest. Squirrels built nests only in mixed-hardwood forest. Overall, this introduced species exhibited nest site selection behavior similar to other tree squirrels, and appears capable of continued spread despite the initial site of introduction on an oceanic island. Knowledge obtained from this research is being used by managers and applied to an eradication program to remove this invasive species from Biscayne National Park.

Seabirds commonly nest colonially on cliffs or inaccessible islands, so that oceanic effects on the quality or quantity of prey fed to chicks more often determine nest success than does terrestrial predation. However, when predators can access nests, impacts can be dramatic. In Kittlitz’s murrelet (KIMU), a rare and recently declining seabird, nests are widely dispersed in poorly accessible areas, growth rates are exceptionally high, and nestling periods are very short. This unique strategy may offset the vulnerability of their ground nests to predators but demands adequate deliveries of high-energy prey. We investigated whether variations in energy content of prey fed to chicks could alter growth rates and resulting duration of exposure to predators, and whether extending predator exposure had important effects on nest success. From 2009‒2016, we measured fish length with cameras, modeled prey energy content from chick energy needs, and measured chick growth rate and nest survival. We monitored an average 17 nests/year (139 total), of which 49% were depredated (almost all by red fox) and 25% survived to fledging. Prey were mainly Pacific sand lance (80%) and capelin (19%), with capelin having 2.3× higher energy per unit length. In a year of slow growth, sand lance energy density needed to increase by 31% from 4.29 to 5.64 kJ/g (within published values), or the proportion of capelin in the diet needed to increase from 5.6% to 27.2%, to achieve maximum chick growth. Adults could supply the energy required for maximum growth by delivering only 1.9 capelin/day versus 5.5 sand lance. Slow growth increased time to fledging by 5 days. This extended exposure to predation could decrease overall nest survival from 14.2% to 13.1%, a relative decrease of 7.7%. With reported breeding propensity of KIMU averaging only 20% and sometimes much lower (range 5 to 45%), even small effects on nest success may be consequential. Although direct predation was the main limitation to nest success, effects of ocean conditions on prey quantity and quality can have overriding effects in some years, and apparently small but substantive indirect effects in other years by mediating exposure to predation. Continued climate warming that adversely affects availability of high-energy fish and allows range expansion of terrestrial predators may have disproportionate effects on species such as KIMU with accessible nests and demands for energy-rich prey.

The photopollution of beaches caused by artificial light sources can interfere with sea turtle hatchlings' ability to orient properly towards the sea. Exhaustion due to extended disorientation crawling may then increase hatchling mortality. This study evaluated the energetic consequences of long-distance crawls in green and loggerhead sea turtle hatchlings. Turtles crawled for 200 m or 500 m on a treadmill, followed by a 30 minute evaluation of swim performance. Metabolic activity was quantified via measures of blood glucose, blood lactate, and oxygen consumption. No significant changes in metabolism resulted from long-distance crawling activity in loggerheads ; however, loggerheads rested for extended periods of time during the crawl trials, often unresponsive to stimuli. This behavior implies that loggerhead hatchlings would be vulnerable to predation or temperature stress due to exhaustion from extended periods of crawling. Further data is required to draw any significant conclusions about long-term disorientatin crawling in green hatchlings. / by Sean Williams. / Thesis (M.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

As regiões tropicais têm sofrido drásticas modificações na paisagem ao longo do tempo. No Brasil, o bioma Cerrado é considerado um dos mais vulneráveis devido à crescente destruição ocasionada pela ação antrópica, sendo o bioma mais ameaçado do mundo. Restam apenas 20% da cobertura original do Cerrado em todo o país e somente 2,2% estão inseridos em áreas protegidas. Com essa crítica situação de conservação, além da rápida destruição de seus hábitats naturais e também por possuir uma elevada riqueza biológica, o Cerrado foi incluso entre os 25 hotspots mundiais. A redução excessiva das áreas nativas pode provocar a extinção de muitas espécies de aves, principalmente espécies especialistas de áreas campestres. Em aves, a seleção de hábitat é entendida como um processo hierárquico de respostas comportamentais que influenciam a sobrevivência e a aptidão dos indivíduos. A diminuição de sítios adequados para a nidificação no ambiente pode ser um fator crítico que determina a extinção local de muitas espécies de aves. Outro aspecto de extrema importância, é a compreensão de fatores relacionados à história de vida das espécies. Descrições detalhadas sobre a biologia reprodutiva da avifauna são de fundamental importância, ainda mais que muitas das espécies de aves neotropicais ainda não possuem descrições sobre informações básicas de suas histórias de vidas. Diante disso, visamos no capítulo I descrever a biologia reprodutiva de Alecturus tricolor e Sporophila pileata, dois Passeriformes dos quais muito pouco se sabe sobre aspectos fundamentais das suas histórias de vida. No capítulo II visamos entender como algumas aves de fitofisionomias campestres de cerrado selecionam o microhábitat para a nidificação e como essas escolhas podem influenciar no sucesso reprodutivo dessas espécies / Tropical regions have undergone drastic changes in the landscape over time. In Brazil, the Cerrado is considered one of the most vulnerable biomes due to increased destruction caused by human action; it is the most threatened biome in the world. Only 20% of the original cover of the Cerrado remains across the country and only 2.2% is included in protected areas. With this critical conservation situation, the rapid destruction of their natural habitats along with its high biological richness, the Cerrado has been included among the 25 global \"hotspots\". Excessive reduction of native areas can cause the extinction of many bird species, principally species specific to grassland areas. Among birds, the habitat selection is understood as a hierarchical process of behavioral responses that influence the survival and fitness of individuals. The reduction of suitable nesting sites in the environment may be a critical factor that determines the local extinction of many species of birds. Another very important aspect is the understanding of factors related to the life history of the species. Detailed descriptions of the reproductive biology of birds are of fundamental importance, even more so since many of neotropical birds still do not have descriptions of basic information of their life histories. Therefore, we aim in chapter I to describe the reproductive biology of tricolor Alecturus tricolor and Sporophila pileata, two Passeriformes of which very little is known about key aspects of their life histories. In Chapter II we aim to understand how some birds of grassland physiognomies of the cerrado select the microhabitats for nesting and how these choices can influence the reproductive success of these species

Following nest emergence, sea turtle hatchling dispersal can be disrupted by artificial light or skyglow from urban areas. Mis- or disorientation increases exposure to predation, thermal stress, and dehydration, could consume valuable energy, and thus influence the likelihood of survival. This study utilized laboratory simulations of extended crawl distances and field observations to investigate the energy cost of disorientation crawling on loggerhead (Caretta caretta) and green (Chelonia mydas) sea turtle hatchlings and the impact on the subsequent swim frenzy. Extended crawls increased oxygen consumption, decreased plasma glucose, and reduced green hatchling swim performance following a 200m crawl. Surprisingly, plasma lactate concentrations did not increase with crawl distance, likely due to frequent rest periods that would, however, increase time on the beach and thus exposure to predators. This research may provide managers with physiological data to determine best practices for sea turtle conservation and adds to the biological knowledge of these animals. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection

Os meliponíneos atuam como importantes polinizadores de espécies nativas nas regiões tropicais e subtropicais e apresentam uma grande relevância para as unidades de conservação. A disponibilidade de sítios de nidificação, conforme a oferta de diferentes substratos (cavidades em árvores e no solo, por exemplo), pode determinar a estrutura da comunidade de meliponíneos. Tendo como área de estudo o Parque Estadual das Fontes do Ipiranga (23º 39\' S, 46º 37\'W), situado em meio de uma intensa urbanização na cidade de São Paulo - SP, este trabalho teve como objetivo principal o levantamento de ninhos de espécies de meliponíneos em duas áreas com fitofisionomias distintas: áreas de estágio sucessional secundário inicial (SI), com menor densidade de indivíduos arbóreos, e áreas de estágio secundário tardio (ST), com maior densidade de indivíduos arbóreos. Foram formuladas as seguintes hipóteses: 1) a riqueza e a diversidade de espécies de meliponíneos serão maiores nas áreas ST; 2) nas áreas ST, a maior disponibilidade de substratos para nidificação (ocos de árvores) implicaria em uma densidade maior de ninhos de meliponíneos, com o predomínio de espécies que nidificam em árvores; 3) nas áreas SI, os valores de riqueza e de abundância relativa de espécies de meliponíneos que nidificam no solo serão maiores que os valores para as espécies que nidificam em árvores, pela baixa densidade de indivíduos arbóreos; 4) ninhos de espécies do gênero Melipona só serão encontrados nas áreas ST, por nidificarem em ocos de árvores com grandes CAPs (circunferência à altura do peito). No total, foram encontrados 14 ninhos, de 4 espécies, todas da subtribo Trigonina. A espécie Paratrigona subnuda, que nidifica no solo, foi a que apresentou a maior abundância relativa de ninhos (n = 11; 78,57 %), com ninhos tanto em áreas SI (n = 2), como em áreas ST (n = 9). As demais espécies estiveram representadas por apenas um ninho cada: Trigona braueri (n = 1; 7,14 %) em SI, Scaptotrigona bipunctata (n=1; 7,14 %) e Trigona spinipes (n = 1; 7,14 %), ambas em ST. As áreas ST apresentaram a maior abundância relativa de ninhos (n = 11, 78,57 %) e, ao contrário do que esperávamos, nessas áreas, a abundância de ninhos subterrâneos foi maior que a de ninhos de árvores, fossem eles de suporte ou de cavidades. Também não foram encontrados ninhos de espécies do gênero Melipona, como suposto. Os valores de diversidade foram praticamente os mesmos (baixos) para ambos os estágios (SI - H\' = 0,60; ST- H\' = 0,64). Já a riqueza e a densidade de ninhos foram significativamente maiores nas áreas ST (SI - riqueza = 2, densidade = 1,43 ninhos/ha; ST - riqueza = 3, densidade = 5,24 ninhos/ha). A densidade de ninhos para toda a área de estudo (3,33 ninhos/ha) foi maior que a média encontrada para outros levantamentos realizados em áreas naturais / Stingless bees act as important pollinators of native species in tropical and subtropical regions and have a great relevance to conservation units. The availability of nesting sites, according to substrates\' supply (cavities in trees and soil, for example), can determine the structure of stingless bees community. This study was conducted in the Parque Estadual das Fontes do Ipiranga (23º 39\' S, 46º 37\'W), situated in the middle of an intense urbanization in São Paulo city - SP. The study aimed to survey the nest of species of stingless bees in two areas with different vegetation types: areas of initial secondary successional stage (SI), with a lower density of individual trees, and areas of late secondary stage (ST), with a higher density of individual trees. The following hypotheses were formulated: 1) richness and diversity of stingless bees species will be higher in the ST areas; 2) in these areas as well, the increased availability of nesting sites (tree hollows) will entail in a higher density of stingless bees nests with a predominance of species that nest in trees; 3) in the SI areas, richness and relative abundance of stingless bees species that nest in the soil will be greater than the values for species that nest in trees, due to the low density of individual trees; 4) nests of species of the genus Melipona will only be found in the ST areas due to their preference to nest in hollows of trees with large CAPs (circumference at breast height). In total, 14 nests of 4 species were found, all of them belonging to the subtribe Trigonina. Paratrigona subnuda, which nests on the ground, presented the highest relative abundance of nests (n = 11, 78.57 %), with nests in both SI (n = 2) areas, as in ST areas (n = 9). The other species were represented by only one nest each: Trigona braueri (n = 1, 7.14 %) in SI, Scaptotrigona bipunctata (n = 1, 7.14 %) and Trigona spinipes (n = 1, 7.14 %), both in ST. The ST areas had the highest relative abundance of nests (n = 11, 78.57 %) and, contrary to what we had expected, in these areas, the number of underground nests was higher than of tree nests, whether they were supportive or cavities. Also contrary to our predictions, no nests of species of the genus Melipona were found. Diversity values were practically the same (low) for both stages (SI - H \' = 0.60; ST - H\' = 0.64). Richness and nest density were significantly higher in ST areas (SI - richness = 2, density = 1.43 nests/ha; ST - richness = 3, density = 5.24 nests/ha). The nest density for the entire study area (3.33 nests/ha) was higher than the average found in other surveys in natural areas