The research in this thesis concerns with the ecology and behaviour of an endangered fossorial rodent, the giant root-rat (Tachyoryctes macrocephalus), in the Afroalpine ecosystem of the Bale Mountains, Ethiopia, and the results are discussed in relation with available ecological data on other fossorial/subterranean rodents. Firstly, this theses is focused on investigating the ecological role of the giant root-rat. The evaluation of root-rat's impact on various ecosystem features, in the first study, highly contributed to the knowledge not only about the species itself but also about the functioning of the ecosystem it inhabits. In fact, the results of the study indicated that the giant root-rat acts as an ecosystem engineer in the Afroalpine grasslands. Secondly, this thesis involves a pilot radio-telemetry study on the giant root-rat focusing on its temporal and spatial activity. Specifically, the results of the second study brought new light to giant root-rats' daily activity, its pattern, amount and seasonal change demonstrating the difference in activity patterns between strictly subterranean rodents and subterranean rodents with aboveground habits such as the giant root-rat. In the third study, we described the space-use patterns of the giant root-rat and revealed several trends in its spatial behaviour that can serve as a strategy to cope with the harsh and changeable environmental conditions in the Afroalpine ecosystem.

Auf der Ostseeinsel Rügen wurde eine 3-jährige Untersuchung zur Siedlungsstruktur, Raum- und Habitatnutzung des Dachses (Meles meles L., 1758) unter besonderer Berücksichtigung der Landschaftszerschneidung und des Landnutzungsmusters durchgeführt. Über 70 % der Inselfläche ist landwirtschaftlich, überwiegend ackerbaulich, genutzt und nur knapp ein Fünftel wird von Wald bedeckt. Während die Zersiedelung und Zerschneidung der Landschaft durch Siedlungs- und Verkehrsfläche im bundesdeutschen Vergleich als sehr gering einzustufen war, ist nach der ?Wende? eine stete Verdichtung des Straßennetzes zu beobachten, die von einem enormen Anstieg der Verkehrsdichte begleitet wird. Die Auswirkungen dieser Rahmenbedingungen wurden anhand von Nahrungsanalysen, eines inselweiten Baukatasters, Fang und Telemetrie einiger Dachse sowie einer Erfassung verkehrstoter Dachse untersucht. Die erfassten Totfunde dienten einer Abschätzung des Gefährdungspotentials unterschiedlicher Straßentypen (Bundesstraße, Landesstraße usw.). Zusätzlich wurde auf Grundlage des Baukatasters, des Totfundkatasters und von Verkehrszählungen der Zusammenhang zwischen Verkehrslast, Siedlungsdichte (des Dachses) und Verkehrsmortalität des Dachses mit Hilfe eines einfachen Modells ermittelt. / On the baltic island of Rügen investigations had been carried for 3 years with regard to distribution, space use and habitat utilization of the European badger (Meles meles L., 1758). Special attention was focused on landscape fragmentation and patterns of land use. More than 70 % of the island is agricultural, almost arable land and just under a fifth is woodland. Before 1990, fragmentation and dessection of the landscape due to housing and roads was low compared with the german average, but after the political "turn" the road system has increased constantly combined with an enormous increase in traffic density. The effect of these conditions on badgers was investigated studying diet composition, surveying and registrating badger setts all over the island, badger-watching and trapping, radio-tracking some badgers and collecting all reported badgers fallen victim to traffic accidents. Relating the road-killed badgers to the length and traffic density of the different road categories, potential danger to be killed by car was estimated. Relating the density of traffic, the density of the badger's local population and its road-mortality was done by simply using data of the sett survey, the road-killed badgers and traffic census.

No description available.

Eighteen prairie rattlesnakes (Crotalus viridis viridis) were tracked using radio-telemetry and 82 snakes were PIT-tagged over a 2-year period in Lethbridge, AB to determine population size, movement patterns, and habitat utilization, and to predict fragmentation effects on the species within an urban locale. Population size was estimated using closed population models at 374 snakes (295 adults) and open population models at 204 snakes (161 adults), greater than an estimate of <50 adults in 2003 (Ernst, 2003) and 2006 (Ernst & Quinlan, 2006). Mean home range sizes, based on 95% minimum convex polygon analysis, differed significantly between years (31.51 ha in 2005, 3.72 ha in 2006). Calculated movement parameters, such as mean distance moved per day, total distance moved over the course of the active season, and frequency of movement varied between years and individuals. Greater-than-expected (under hypotheses of even habitat choice) utilization was observed in habitat types located within coulee and flood plain areas, with apparent preference towards unbroken parcels of grassland or cottonwoods, whereas less-than-predicted utilization of agricultural habitat type was observed. Fragmentation effects on prairie rattlesnake movement and occurrence were examined through modeling and were found to coincide with observed species’ locations, suggesting that prairie rattlesnakes are undergoing modification of movement patterns to avoid highly concentrated human density or use. Influence of weather on the use of vegetative ground cover was observed, as it was accessed more by prairie rattlesnakes at higher temperatures. Recommendations towards future management of the prairie rattlesnake population in Lethbridge are given, including protection of the Bridge View Drive site and inclusion of varied habitat types and terrain when planning habitat and wildlife corridors. Management decisions that ensure remaining habitat parcels and connective areas near rattlesnake foraging or movement corridors are also advocated. Identification of future research focuses include studies on juvenile survivorship, genetic structure, and vehicle-related mortality. / xii, 83 leaves : col. ill., col. maps ; 29 cm

This research address the problem of inferring, through Radio-Frequency Identification (RFID) tracking data, the graph structures underlying social interactions in a group of rhesus macaques (a species of monkey). These social interactions are considered as independent affiliative and dominative components and are characterized by a variety of visual and auditory displays and gestures. Social structure in a group is an important indicator of its members’ relative level of access to resources and has interesting implications for an individual’s health. Automatic inference of the social structure in an animal group enables a number of important capabilities, including: 1. A verifiable measure of how the social structure is affected by an intervention such as a change in the environment, or the introduction of another animal, and 2. A potentially significant reduction in person hours normally used for assessing these changes. The behaviors of interest in the context of this research are those definable using the macaques’ spatial (x,y,z) position and motion inside an enclosure. Periods of time spent in close proximity with other group members are considered to be events of passive interaction and are used in the calculation of an Affiliation Matrix. This represents the strength of undirected interaction or tie-strength between individual animals. Dominance is a directed relation that is quantified using a heuristic for the detection of withdrawal and displacement behaviors. The results of an analysis based on these approaches for a group of 6 male monkeys that were tracked over a period of 60 days at the Yerkes Primate Research Center are presented in this Thesis.

Auf der Ostseeinsel Rügen wurde eine 3-jährige Untersuchung zur Siedlungsstruktur, Raum- und Habitatnutzung des Dachses (Meles meles L., 1758) unter besonderer Berücksichtigung der Landschaftszerschneidung und des Landnutzungsmusters durchgeführt. Über 70 % der Inselfläche ist landwirtschaftlich, überwiegend ackerbaulich, genutzt und nur knapp ein Fünftel wird von Wald bedeckt. Während die Zersiedelung und Zerschneidung der Landschaft durch Siedlungs- und Verkehrsfläche im bundesdeutschen Vergleich als sehr gering einzustufen war, ist nach der ?Wende? eine stete Verdichtung des Straßennetzes zu beobachten, die von einem enormen Anstieg der Verkehrsdichte begleitet wird. Die Auswirkungen dieser Rahmenbedingungen wurden anhand von Nahrungsanalysen, eines inselweiten Baukatasters, Fang und Telemetrie einiger Dachse sowie einer Erfassung verkehrstoter Dachse untersucht. Die erfassten Totfunde dienten einer Abschätzung des Gefährdungspotentials unterschiedlicher Straßentypen (Bundesstraße, Landesstraße usw.). Zusätzlich wurde auf Grundlage des Baukatasters, des Totfundkatasters und von Verkehrszählungen der Zusammenhang zwischen Verkehrslast, Siedlungsdichte (des Dachses) und Verkehrsmortalität des Dachses mit Hilfe eines einfachen Modells ermittelt. / On the baltic island of Rügen investigations had been carried for 3 years with regard to distribution, space use and habitat utilization of the European badger (Meles meles L., 1758). Special attention was focused on landscape fragmentation and patterns of land use. More than 70 % of the island is agricultural, almost arable land and just under a fifth is woodland. Before 1990, fragmentation and dessection of the landscape due to housing and roads was low compared with the german average, but after the political &amp;quot;turn&amp;quot; the road system has increased constantly combined with an enormous increase in traffic density. The effect of these conditions on badgers was investigated studying diet composition, surveying and registrating badger setts all over the island, badger-watching and trapping, radio-tracking some badgers and collecting all reported badgers fallen victim to traffic accidents. Relating the road-killed badgers to the length and traffic density of the different road categories, potential danger to be killed by car was estimated. Relating the density of traffic, the density of the badger's local population and its road-mortality was done by simply using data of the sett survey, the road-killed badgers and traffic census.

Conventional methods for health assessment of wild-caught and stranded seals were used to describe the disease status of harbor seals in California. Clinical chemistry, infectious disease prevalence, immune function, and contaminant data were collected to evaluate harbor seal health with data collected from three groups of seals. Wild-caught seals of all ages were sampled at two locations: San Francisco Bay (a heavily urbanized estuary) and Tomales Bay (a less developed control site). Stranded seals entered rehabilitation from a more extensive portion of the California coast which included the locations where seals were caught. Hematology reference intervals were generated to provide a baseline for health assessment among the seals. Individual variability in blood variables among seals was affected by age, sex, location, and girth. Disease surveillance focused on pathogens known to cause lesions in harbor seals, zoonoses, and those with terrestrial sources. Specific pathogens of interest were E coli, Clostridium perfringens, Vibrio spp, Campylobacter spp, Salmonella, Giardia, Cryptosporidium, avian influenza virus, Brucella, Leptospira spp., Toxoplasma gondii, Sarcocystis neurona, and Neospora caninum, Leptospira spp, and phocine and canine distemper virus. There was evidence of exposure to all pathogens except for phocine distemper virus. Simple measures of immune response were used to evaluate the immune function of harbor seal pups in rehabilitation that had evidence of previous bacterial infection. The swelling response to a subcutaneous injection of phytohemagglutinin (PHA) was positively associated with growth rate, possibly illustrating the energetic trade-offs between growth and immunity. Blubber contaminant concentrations (PCBs, DDTs, PBDEs, CHLDs, and HCHs) in harbor seal pups were grouped by extent of suckling and strand location. The ratio of PCB:DDT was increased in San Francisco Bay and decreased in Monterey Bay compared with other locations along the coast. Pups that weaned in the wild, lost weight and then stranded had the highest contaminant levels, equivalent to the concentrations detected in stranded adult harbor seals. Dispersal and survival were monitored by satellite telemetry in harbor seal pups released from rehabilitation and recently weaned wild-caught pups to assess the effect of condition, health, and contaminant levels on survival probability. Increased contaminant levels and decreased thyroxine (T4) were associated with decreased survival probability. Increased mass, particularly among the rehabilitated pups, was associated with increased survival probability. This study demonstrates that health and survival of harbor seals pups along the central California coast are impacted by human activities such as contaminant disposal, pathogen pollution and boat traffic, although the variability in individual health measures requires carefully designed studies to detect these effects.

A growing body of work reveals that animal-mediated pollination is negatively affected by anthropogenic disturbance. Landscape-scale disturbance results in two often inter-related processes: (1) habitat loss, and (2) disruptions of habitat configuration (i.e. fragmentation). Understanding the relative effects of such processes is critical in designing effective management strategies to limit pollination and pollinator decline. I reviewed existing published work from 1989 to 2009 and found that only six of 303 studies separated the effects of habitat loss from fragmentation. I provide a synthesis of the current landscape, behavioral, and pollination ecology literature in order to present preliminary multiple working hypotheses to explain how these two landscape processes might independently influence pollination dynamics (Chapter 2). Despite the potential importance of independent effects of habitat fragmentation, effects on pollination remain largely untested. Studies designed to disentangle the independent effects of habitat loss and fragmentation are essential for gaining insight into landscape-mediated pollination declines. I also found that the field of landscape pollination ecology could benefit from quantification of the matrix, landscape functional connectivity, and pollinator movement behavior. To test the hypothesis that pollinator movement can be influenced by landscape configuration, I translocated radio-tagged hummingbirds across agricultural and forested landscapes near Las Cruces, Costa Rica (Chapter 3). I found return paths were on average more direct in forested than in agricultural landscapes. In addition, movement paths chosen in agricultural landscapes were more forested than the most direct route suggesting that hummingbirds avoided crossing open areas when possible. To determine if differences in pollinator movement translated to differences in plant reproduction, I tested the relative importance of landscape composition versus configuration on the reproductive success of Heliconia tortuosa, a hummingbird-pollinated forest herb (Chapter 4). I used a stratified random sampling design to select sites across orthogonal gradients in patch size, amount of forest, and elevation. I tested four landscape change hypotheses (i.e., local, landscape composition, landscape fragmentation, and fragmentation threshold). I found that Heliconia reproduction supported both the local site and landscape fragmentation hypotheses. Seed set increased with increasing forest patch size independent of amount of forest in the surrounding landscape. I also found that increasing patch size positively influenced the relative abundance of pollinators. The observed differences in seed set likely resulted from differences in hummingbird movements (Chapter 3) and/or abundance under different landscape configurations. / Graduation date: 2013