I studied aspects of fisher (Martes pennanti) population ecology on the Hoopa Valley Indian Reservation in northern California to fill critical information gaps relative to timber management and its effect on the status of fishers, a candidate for listing under the U.S. Endangered Species Act. A decline in mark-resight density estimates of fishers from 1998 (52/100 km2; 95% CI = 43–64) to 2005 (14/100 km2; 13–16) was likely due to changes in prey habitat suitability, increased predation pressure, and/or disease. The decline was also indicated by catch-per-unit effort indices, but not by camera station or track-plate station indices. Colleagues and I developed and tested methods of collecting mark-recapture data using genetic marking, passive integrated transponder (PIT) tag technology, and digital, passive-infrared photography that could be used in a demographic monitoring protocol. The comparatively high cost of PIT tag reading equipment and genetic analyses makes the use these methods dramatically more expensive and yield less demographic data compared to using a traditional mark-recapture approach using only live trapping. By monitoring 40 radio-marked, breeding age (≥ 2 years old) females during 2005–2011, we found that 87% exhibited denning behavior and 65% of these were successful in weaning at least one kit (mean = 1.9). Of 14 kits radio-marked in their first fall, 3 died prior to dispersal, 3 lost collars, and the other 8 established home ranges 0.8–18.0 km away from natal areas. Nipple size (width multiplied by height of the largest anterior nipple), evaluated as a predictive index of female fisher reproductive success, differed among nonbreeders vs. attempted and current breeders. A predictive index for use in assigning reproductive status to females with unknown reproductive histories had an overall correct classification rate of 81% and a chance-corrected measure of prediction of 69.5%. These results illustrate the value in establishing long-term, accurate programs to monitor populations of imperiled species which strive to determine cause and affect relationships to changes in populations and ultimately, modeling habitat fitness. The relatively low reproductive rate of female fishers brings into question the species ability to demographically respond to increased rates of juvenile and adult mortality with increased reproduction and/or survival. The limited dispersal capability of juvenile fishers restricts ability to rescue vanishing local populations from extirpation, re-inhabit landscapes from which they were previously extirpated, and establish the functional connectivity of metapopulations.

Thesis (Ph.D.)--Texas Christian University, 2007. / Title from dissertation title page (viewed Dec. 10, 2007). Includes abstract. Includes bibliographical references.

Thesis (Ph. D.)--Göteborg University, 2003. / Added t.p. with thesis statement inserted. Includes bibliographical references.

Thesis (Ph. D.)--Texas Christian University, 2007. / Includes bibliographical references (leaves 258-279). Also available online as a PDF file.

Thesis (Ph. D.)--Göteborg University, 2003. / Added t.p. with thesis statement inserted. Includes bibliographical references.

Thesis (Ph. D.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 165-[202]).

Thesis (B.Soc.Sc.(Hons.))--University of Waikato, 2006. / Includes bibliographical references (leaves 132-140) Also available via the World Wide Web.

Habitat selection has long been viewed as a multi-scale process. Observed species responses to resource gradients are influenced by variation at the scale of the individual, population, metapopulation, and geographic range. Understanding how species interact with habitat at multiple levels presents a complete picture of an organism and is necessary for conservation of endangered species. The main goal of this dissertation is to evaluate distribution, relative abundance, and habitat selection of a rare species, the pygmy rabbit Brachylagus idahoensis, at multiple scales in order to improve management and conservation for this species. At the broadest scale, pygmy rabbit occurrence and relative abundance were modeled in the Duck Creek allotment of northern Utah using a hierarchical spatial model. Pygmy rabbits are not easily observable, and the model used two levels of indirect detection to make statistically rigorous spatial predictions. We found that the model predicted the general pattern of rabbit occurrence and abundance within the study area, and that there was spatial heterogeneity in the probability of pygmy rabbit occurrence within a study domain that was known to be occupied. The resulting model framework could be used to develop a long-term monitoring program for pygmy rabbits and other species for which hierarchically nested levels of indirect observation are collected. The mid-scale analysis evaluated pygmy rabbit home range placement and movement with respect to sagebrush removal treatments using null models based on an optimal central place foraging behavior. While placement of home-range centers did not appear to be affected by the treatments, within-home range movements were farther from treatments than expected by the null models for two rabbits (of eight), and rabbits that approached treatment edges were less likely to enter treatments than expected by chance. Rabbits are not extirpated from sites that have been treated, but the observed reluctance to enter treated patches calls for caution when conducting sagebrush removal treatments near occupied pygmy rabbit burrows. At the finest level of resolution, the spatial ecology of pygmy rabbit use of burrows was evaluated. Both the placement of burrows in general and pygmy rabbit use of burrows were clustered. While the habitat gradients experienced by each of the rabbits evaluated affected the modeled habitat selection responses, some generalities were observed. Selection of high cover suggests that pygmy rabbit use of burrows may be linked to predator avoidance behavior. Additionally, pygmy rabbit use of clustered burrows affects management actions including: habitat modeling, monitoring, and species introduction. Explicit attention to resource distribution will improve efforts to predict species responses to management actions.

Tigers (Panthera tigris Linnaeus, 1758) are in danger of extinction. Their populations have declined from ~100,000 to only ~3,000 individuals in a century and their habitat has shrunk to less than 7% of the historic range. Of the five extant tiger subspecies, the Sumatran tiger (Panthera tigris sumatrae Pocock, 1929) is the most seriously threatened. Currently determined as Critically Endangered under IUCN criteria, the Sumatran tiger is likely to become extinct unless effective conservation measures are enacted. Threats to the tiger include habitat destruction, killing due to conflict with humans and livestock, and poaching for illegal wildlife trade. Long-term survival of Sumatran tigers depends largely on the effectiveness of current conservation efforts in every tiger landscape. Successful conservation and management require accurate information on ecology of the species upon which decisions can be based. This study investigated basic ecological aspects of tigers and developed strategies for management and restoration to improve tiger viability in the Central Sumatra landscape. This landscape is comprised of natural forests and plantations managed for timber and agricultural commodities. The first chapter assesses the variation in tiger abundance across forest types in Southern Riau, and over time in Tesso Nilo National Park, all in Central Sumatra. Using camera traps, my team and I systematically sampled five blocks representing three major forest types in the region: peat land, flat lowland, and hilly lowland. I found that tiger abundance varied by forest type and through time. Excluding two sampling blocks where no tigers were photographed, the lowest tiger density was in peat land forest of Kerumutan, and the highest density was in the flat lowland forest of Tesso Nilo. Repeated sampling in the newly established Tesso Nilo National Park documented a trend of increasing tiger density (SE) from 0.90 (0.38) individuals/100 km2 in 2005 to 1.70 (0.66) individuals/100 km2 in 2008. Overall, tiger densities from this study were lower than most previous estimates from other parts of Sumatra. The trend of increasing tiger density in Tesso Nilo, however, suggests that the tiger population could be augmented by protection of habitats that were previously logged and severely disturbed. The second chapter examines the occupancy and habitat-use of the tiger across the major landcover types (natural forest, acacia plantation, oilpalm plantation, rubber plantation, and mixed agriculture). I found that tigers used some plantation areas, although they significantly preferred forests over plantations. In all landcover types, sites with tiger detections had thicker understory cover than sites without tiger detection. Modeling tiger occupancy while recognizing that probability of detection is not always perfect, I found that tiger occupancy covaried positively and significantly with altitude and negatively, but not significantly, with distance-to-forest-cores. Probability of habitat use by tigers covaried positively and significantly with understory cover and altitude, and negatively and significantly with human settlement and landcover rank. The results suggested that with adjustments in plantation management, tigers could use or roam through plantations within the habitat mosaic provided that the plantations had adequate understory cover and low level of human activity. They also could use riparian forests (as corridors) and smaller forest patches (as stepping stones) to travel between the main habitat patches across the forest and plantation landscape. The third chapter investigates the ecological characteristics and possible inter-specific interactions among wild felids, including tigers and smaller cats, based on data collected using systematic camera trapping in combination with information on their natural history. I found that despite overlap in resource needs of the five felid species, each appears adapted to specific environmental conditions allowing coexistence with other felids. The five felid species used statistically different elevations, with the golden cat found to inhabit the highest elevation. Two-species occupancy models showed that only leopard cats were found to co-occur with other felid species more frequently than expected by chance under independence. Species of similar size or eating similar-sized prey generally tended to have low coefficients of temporal activity overlap, suggesting avoidance. Temporal avoidance is likely occurring in three pairs of felids, namely clouded leopards and golden cats, clouded leopards and marbled cats, and marbled cats and leopard cats. Based on the differences in morphological and ecological characteristics, and on patterns of spatial and temporal occurrence, I identified six possible mechanisms by which felids in Central Sumatra maintain coexistence. I discussed the implications of this study for management, focusing on how to balance diversity and abundance of felids. The fourth chapter presents the tiger distribution models as a case study to illustrate the importance of accounting for uncertainty in species distribution mapping. I applied four modeling approaches, differing in how the response variable (tiger presence) is constructed and used in the models. I compared the performance and output of different models based on the relative importance of variables, descriptive statistics of the predictions, cross comparison between models using an error matrix, and validation using tiger presence data collected from independent surveys. All models consistently identified forest area within the grid as one of the most important variables explaining tiger probability of occurrence. Three models identified altitude as another important factor. While the four models were consistent in predicting relatively high probability of tiger occurrence for high elevation forest areas such as Rimbang Baling and Bukit Tigapuluh, they generally had a lower level of agreement in predictions for low elevation areas, particularly the peat land in the northeastern part of the study area. Based on the results of cross evaluation of the predictions among models and validation with the independent data, I considered the occupancy model to be superior to the others. If data collection format permits, I advocate the use of occupancy instead of the other modeling techniques to develop predictive species distribution maps. The last chapter constructs a strategy to restore the tiger population across the ecosystem of Central Sumatra through integration of knowledge on tiger ecology from previous chapters with consideration of the ecological conditions of the landscape in the region. The strategy combines existing knowledge of tiger conservation and regional ecosystem restoration. It recognizes the limitations and challenges of traditional nature protection and considers existing and new opportunities. Emerging opportunities and new mechanisms, such as direct and indirect economic incentives for nature conservation and restoration, are taken into account. These, coupled with increased awareness of the stakeholders, better policies and implementation of good governance, and the willingness and know-how to maintain coexistence with wildlife among the local people, are expected to support and accelerate the recovery of tigers and their ecosystem. / Ph. D.