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.

Amphibians and aquatic invertebrates have complex life histories that link aquatic and terrestrial food webs. It has been suggested that amphibian reproduction is an important source of carbon to some aquatic systems. This process of energy flow may be shaped by shifts in habitat selection in response to predators. We hypothesized that predators decrease colonization and oviposition of prey, reducing active inputs. Thus predation risk is expected to shift the relative amounts of active and passive subsidies. We manipulated the presence of fish predators in aquatic mesocosms. Results suggest hylid treefrog eggs and hydrophilid beetles were less abundant in predator treatments. This difference in oviposition and colonization translated into small reductions in calories and ash free dry mass of active inputs. However, passive allochthonous inputs were more than double active amounts and variable, therefore relative amounts of active and passive inputs did not differ across the levels of predation risk.

Master of Science / Biology / Alice Boyle / Dispersal is a behavior common to virtually all taxa with important consequences for gene flow, demography, and conservation. Mobile animals such as birds frequently engage in breeding dispersal, but the factors shaping this behavior are not well understood. In mid-continental grasslands, preliminary evidence suggested that Grasshopper Sparrows (Ammodramus savannarum) engaged in breeding dispersal within a single breeding season. This intriguing pattern shaped my research questions: (1) what are the patterns of within-season breeding dispersal in Grasshopper Sparrows? (2) why do some individual sparrows disperse, and others do not? and (3) what shapes settlement decisions following dispersal? I tested hypotheses based on spatial and temporal variation in nest predation, nest parasitism, and food availability. I studied Grasshopper Sparrows at 18 experimentally-managed watersheds with different fire and grazing regimes at Konza Prairie Biological Station during 2013-2015. To describe patterns, I combined re-sighting of 779 marked individuals, territory mapping, and radio-telemetry to quantify territory densities, turnover, and dispersal distances. To determine if nest predation or nest parasitism affected dispersal, I monitored the fate of 223 nests. I estimated food intake rates using plasma metabolites, and prey availability using sweep sampling. Densities of territorial Grasshopper Sparrows varied seasonally in management-specific ways. Turnover was remarkably high, with over half of territorial males being replaced each month. Over a third of males changed territories within-season, dispersing 0.1-9 km between breeding attempts. Dispersal decisions were related to past nest predation, but not nest parasitism. Dispersal likely yields fitness benefits, as sparrows that dispersed increased their chances of nest survival by 23% relative to site-faithful individuals. However, food availability did not affect settlement decisions. My study provides the first evidence of within-season breeding dispersal in Grasshopper Sparrows, and represents one of few tests of alternative hypotheses explaining dispersal decisions of songbirds. My results are consistent with a growing literature on the role of predation shaping dispersal, but suggest, somewhat surprisingly, that food is not important in post-dispersal habitat selection. High dispersal capacity coupled with adaptability to temporal and spatial change may be typical of grassland songbirds, implying that demographic studies and management decisions must consider their mobility for conservation.

A research report submitted to the Faculty of Science, University of Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Science (Resource Conservation Biology). Johannesburg, 2015 / The vegetation of the Kgaswane Mountain Reserve, in North West Province, South Africa, was mapped according to seven vegetation structure types, based on tree density and height, and grass height. Free-living ticks were collected by drag-sampling the vegetation from each structure type in November 2014, prior to the onset of the summer rains, and February 2015, once most of the seasonal rains had fallen. Eland (Taurotragus oryx) location information was recorded from four GPS collared cows over the two sample periods. Tick abundance was consistently lower in shorter, open, more exposed vegetation structure types, and higher in more sheltered types. Position higher up in the landscape nullified the positive impacts of trees on beneath-canopy microclimate in tall open woodlands, as indicated by comparatively lower tick numbers than in more sheltered woodland types. Tick abundance is influenced by vegetation structure and the availability of hosts. The majority of ticks trapped during both periods were larvae, with nymphs mostly present in November and adults mostly present later in the season, indicating the seasonal nature of tick cohort recruitment. Eland calving behaviour centred on areas with low adult tick abundance. Eland did not respond to total tick abundance during either sampling period. They did select areas with low adult tick abundance, and avoided areas with high adult tick abundance. This corresponded with an improvement in upland forage quality, which allowed them to avoid foraging in areas with high adult tick abundance. It is plausible that the potential for infestation by adult ticks may be a supplementary influence driving the use of space by eland.

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science. Johannesburg, 2016. / Resource selection by animals is a hierarchical process, reflecting the spatio-temporal heterogeneity in biotic and abiotic environmental conditions and resources. In savannah ecosystems, the availability and nutritional quality of forage resources across the seasonal cycle constitute two of the main drivers of feeding choices, seasonal movements, and, ultimately, population dynamics of large herbivores. As a consequence of the increasing insularisation of protected areas in southern Africa, the understanding of the ecological requirements of confined populations of nomadic ungulates constitutes a crucial issue for their management. The study aimed at determining the effects of forage quality and availability across the seasonal cycle on the home range occupation and resource selection by eland in an insular-like protected area, the Kgaswane Mountain Reserve (KMR) in South Africa. I focused on three spatio-temporal scales of selection: seasonal home range selection over the available landscape; habitat selection within the seasonal home range; and selection for plant species included in the diet. The main objectives at the scales of landscape and habitat selection were: 1) to determine the extent and location of the seasonal home ranges utilised by collared adult female eland in the KMR, in order to identify the seasonally favoured resource units within the available landscape; and 2) to determine the influence of environmental drivers, including the seasonal variation in forage quality and abundance, on resource selection by eland at the two different scales. Four adult female eland were fitted with GPS collars, over the course of two years. The extent and location of annual and seasonal home ranges were estimated using a-LoCoH. The influence of environmental factors, including vegetation-type, burnt areas, and NDVI, on landscape- and habitat-scale selection of used locations at peak feeding times over available scattered points was tested using mixed-effects logistic regression models. Despite the small size of the KMR, eland occupied spatially distinct dry and wet season ranges. The dry season ranges were smaller than their wet season counterparts, and During the dry season, seasonal ranges were small, and were located in moderate to very green (as indicated by NDVI values) woodland areas in respect to the available landscape. Eland selected for dry grassland, wet grassland, and open shrubland (associated with low NDVI levels) during the wet season, when they coalesced into a nursery herd and occupied a relatively large home range. The selective use of burnt areas over the available landscape units was mostly restricted to the wet season, after a green herbaceous flush had been prompted by rainfall events. Within the seasonal home ranges, eland preferentially foraged on burnt woodland and open shrubland, where re-growth of woody plants was also available. The study animals also selected for locations characterized by low vegetation greenness and biomass as a consequence of the concentration of foraging activities in open areas where low-lying browse was accessible. At the smallest scale considered for this study, the two main objectives were: 1) to determine the changes in the use of vegetation types and burnt areas during foraging activities between two different seasons; 2) to determine forage selection at the plant species scale, as influenced by the phenophase of grasses and browse. In March-April 2015 (wet-early dry transition season) and July-August 2015 (mid-dry season), feeding sites of eland were located through both VHF-tracking and scanning from vantage points. Characteristics of used feeding sites were only descriptively addressed, and included vegetation type, burning, canopy cover, and soil catenal position. The greenness and basal cover of plant species were also recorded. Availability, acceptance, and dietary contribution for each species were calculated for the two seasons, while the influence of phenological traits on plant species selection was investigated through mixed-effects logistic regression models. Woody plants were consumed in larger proportions than grasses and herbaceous forbs during the entire study period. Woody forbs and shrublets such as Lippia javanica and Athrixia elata were particularly favoured. Eland targeted species offering high proportions of green leaves. During the wet-early dry transition, the deciduous Vangueria parvifolia was particularly selected for, while the consumption of evergreen species, including Searsia lancea, increased during the dry season. Most of the observed grazing took place on flushing burns during the wet-early dry transition. The decline in grass consumption was paralleled by a considerably lowered use of the burns and of the dry grassland during the dry season, as also reflected by collars data. The results indicated that eland in the KMR adjusted their landscape and habitat selection in response to spatio-temporal variations in the availability and quality of food resources. During the wet season, flushing burns provided accessible green forage to nursery herds. Conversely, evergreen woody plants probably represented a crucial resource for eland during the limiting dry season, when herbaceous plants were mostly dormant and foliage on deciduous species was unavailable. Therefore, environmental heterogeneity at different spatial scales likely constitutes a key factor for the persistence of eland populations in small, fenced reserves. / LG2017

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg in fulfillment of the requirements for the degree of Masters in Science. Johannesburg, August 2016. / Resource selection by herbivores is driven by processes operating across a multitude of spatial scales and is influenced by a variety of biotic and abiotic environmental conditions and resources across the landscape. Spatial scales levels are crucial in habitat selection studies because they affect the interpretation of results and what may appear important at one level may not be relevant at another. Decisions made by animals at these levels can influence animal movements and hence the spatial distribution of populations. In this way, the use of resources across different scales by individual and groups of animals can be linked to population performance as a whole. Within home ranges, habitat use is mostly influenced by variation of food resources and water availability together with competition and predation risk. The study aimed to determine sable home range extent and habitat use and to test how predation, competition and other environmental factors influenced the selection of areas within these home ranges, in the thriving sable population of the Gorongosa National Park (GNP), Mozambique. Two adult females, one per herd, were fitted with GPS collar providing 5 hours interval GPS coordinates over a year, which were used to determine the annual and seasonal home ranges extents. Home ranges were then overlaid with vegetation map to analyse habitat use. Contrary to expectation, sable home ranges in this study were larger than those found in previous studies. The herds did not limit their habitat use to woodlands, using also open grasslands, drainage lines and bottomlands that retained green grasses during the dry season. Both herds expanded their ranges during the dry season, searching for those areas that still retained green grasses and searching for remaining water sources. For the resources selection within home ranges, I used the same GPS collar coordinates to fit seasonal logistic regression models with biotic factors (predation risk and competition) and with environmental variables (distance from water, distance from roads, elevation, slope, NDVI, vegetation types and landscape). Results show that sable were less prevalent in areas with high predation risk, but herds differed in prevalence with competitors, one herd favouring areas with high reedbuck concentrations and the other favouring low concentrations. Effects of environmental variables were different between seasons and between herds, being distance from water, distance from roads, greenness and elevation the most influential environmental. Both herds, however, avoided low elevation areas during the wet season, probably in order to avoid areas flooded during this period. As conclusion, predation risk and competition influenced selection within home ranges by sable in the GNP, despite low densities of potential competitors and lions. Nevertheless, this influence seems to not be enough yet to limit the success of the population. The herds also showed evidences of being affected by dry season, as demonstrated by the home ranges expansions during this period. With increase of herbivores population other that sable, and consequently increase competition and decrease of availability of resources, this could lead to reduction of growths percentages of the sable population in the park in the future. / MT2018

Humans have a large impact on biodiversity, especially by causing habitat loss and habitat degradation but also through human-induced climate change. Because of habitat loss and habitat degradation the Middle-spotted woodpecker (Dendrocopos medius) went extinct in Sweden 1983. Globally the Middle-spotted woodpecker is today listed as least concern but because of human-induced climate change the species might be threatened in the whole world in the future. Different ways to help the species is by protection of potential habitat, restoration or reintroduction. The aim of this study is to help the Middle-spotted woodpecker survive in the future by facilitate its potential progress to Sweden, Linköping. One way to help the species is by investigating if a reintroduction is possible. Therefore, I created a habitat model of the Middle-spotted woodpecker based on published studies and used the model to analyze the landscape for possible sites of reintroduction. Results from published studies showed that the species require at least 20 hectares oak forest per breeding pair, a high density of mature oak and more potential habitat to distribute to, within a 10-kilometer distance. Four areas in Linköping fulfilled all the requirements but only two of them were situated in less than 10 kilometers from each other. A successful reintroduction of the Middle-spotted woodpecker requires a landscape with at least 15-20 potential habitat in a near distance to each other. Therefore, a reintroduction of Middle-spotted woodpecker is not possible in Linköping unless more habitats is restored.

The first of five chapters describe the study area and study species, including a short description about the impetus for this research. The second chapter describes a unique hydrologic model for application in tidal ecosystems. The second chapter represents new information on the effects of various abiotic and biotic factors on foraging wading birds in this highly dynamic environment. The third chapter identifies important factors affecting the abundance of foraging wading birds in intertidal environments. The fourth chapter presents a study of the foraging habitat preferences of two wading bird species in intertidal environments. The fifth chapter describes a conceptual model of wading bird foraging ecology and a predictive model of foraging habitat in intertidal zones. The conceptual model captures the major drivers and linkages between the abiotic and biotic variables thought to affect wading bird foraging abundance in intertidal habitats. The conceptual model also identifies major knowledge gaps in our understanding of foraging ecology of wading birds in coastal intertidal areas. The predictive model of foraging habitat is meant to be used by resource managers, but its framework may be useful for ecological studies in general. The final and sixth chapter provides a summary of all the major findings. Each chapter has been written so as to be independent of the other chapters. As such, a full background, along with a discussion of the relevance of the chapter's findings is provided for each chapter. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

Informações sobre o uso do espaço são importantes para o entendimento de processos ecológicos que envolvem uma espécie e a determinação de seu estado de conservação. Tais informações são escassas para o gênero Mazama, o mais diverso entre os cervídeos neotropicais, sendo que desenvolver metodologias para obtenção de dados ecológicos do gênero torna-se fundamental para qualquer ação de manejo envolvendo o grupo. O estudo do DNA fecal surge como uma ferramenta importante para viabilizar a coleta sistemática de informações sobre o gênero. Assim, o presente trabalho visou a estimar a área de vida e a seleção de hábitat do veado-catingueiro, comparando duas metodologias, com intuito de avaliar a aplicação do DNA fecal como alternativa para se estudar a espécie. O trabalho contou com 6 animais que tiveram suas localizações obtidas a cada 13 horas por colares GPS, no período de um ano. Nesse mesmo período e na mesma área, foram coletadas mensalmente amostras fecais, gerando um total de 830 amostras, cujo DNA foi extraído para identificação genética. A espécie das amostras foi determinada com o uso de um marcador mitocondrial (cit-b), e a identificação individual, com um painel de 11 microssatélites. Os valores de área de vida pelo método do MPC 95% variaram de 33 ha a 97 ha, e pelo método Kernel com 95% das localizações, variaram de 17 ha a 77 ha. Observou-se que as áreas de vida são alocadas nos diferentes habitats da região conforme o disponível (p = 0,072), porém são utilizadas internamente de forma selecionada (p=0,001). Neste nível, a espécie apresentou preferência pelos hábitats de cerrado e campo cerrado e evitou o campo (p < 0,005). Foram identificadas 670 amostras de veado-catingueiro e 15 genótipos únicos. A análise espacial das fezes também sugeriu uso desproporcional dos hábitats em relação à sua disponibilidade, sendo que a comparação direta entre os dois métodos revelou iguais distribuições no nível de espécie (p=0,178). As amostras individualizadas sugeriram um padrão de alta sobreposição de área de uso por diferentes indivíduos, mas avanços são necessários para melhor elucidar a questão. Perante os resultados observados, entende-se que há muito em se avançar na análise molecular das fezes que, realizada em larga escala, pode fornecer respostas importantes anteriormente inviáveis para espécies florestais. / Space use information is a key element to understand the ecological processes regarding a species and its conservation status. Such information is scarce for the genus Mazama, the most diverse group among Neotropical deer. The development of methods to obtain ecological data is fundamental to management actions concerning the group. The study of fecal DNA emerges as an important tool to enable systematic information collection about Mazama genus. Therefore, the present study aimed to estimate the home range and habitat selection of brown brocket deer comparing two methodologies in order to assess the application of fecal DNA as an alternative to study this species. Six animals were monitored with GPS collars and their location data was collected every 13 hours within one year time. Fecal samples were collected monthly in the same period and in the same area, generating a total of 830 samples whose DNA was extracted for genetic identification. The species identification was determined by a mitochondrial marker (cit-b) and individuals were identified applying a panel of 11 microsatellites. Home range was 33-97 h by MPC 95% and 17-77 h by Kernel 95%. Home rages are allocated in different habitats as available in the region (p = 0.072), but its use is internally selected (p = 0.001). At this level, the species showed preference for \"cerrado\" and \"campo cerrado\" habitats and avoidance to open field areas (p < 0.005). Genetics analysis identified 670 brown brocket deer samples and 15 unique genotypes. Feces spatial analysis suggested disproportionate use of habitats in relation to their availability in the field and the direct comparison between the two methods revealed equal distributions at the species level (p = 0.178). The genotyped samples suggested an overlapping home range pattern for different individuals, but advances are needed to further elucidate the issue. There is need for improvements in feces molecular analysis and, if held on large scale, it can provide important and previously unviable answers for forest species.

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