Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 190-195). Also available on the World Wide Web.

Data derived largely from ecclesiastical (mostly churchwardens') accounts, foxhunting statistics, local scientific society records and 19th and 20th century literature sources from a wide range of published material, have provided detailed evidence of the status and changes in distribution over the past four centuries in Yorkshire for fox (Vulpes vulpes), badger (Meles meles), otter (Lutra lutra), pine marten (Martes martes), stoat (Mustela erminea), weasel (M. nivalis), polecat (M. putorius), American mink (M. vison), wildcat (Felis silvestris) and domestic cat (Felis catus). In the case of the domestic cat, questionnaire surveys quantified population sizes and predatory activity in rural, suburban and urban situations. Evidence of the former distribution of all the carnivores studied provides a credible historical basis for biodiversity action planning and the substantial archived database and bibliography provide further research opportunities.

Data derived largely from ecclesiastical (mostly churchwardens¿) accounts, foxhunting statistics, local scientific society records and 19th and 20th century literature sources from a wide range of published material, have provided detailed evidence of the status and changes in distribution over the past four centuries in Yorkshire for fox (Vulpes vulpes), badger (Meles meles), otter (Lutra lutra), pine marten (Martes martes), stoat (Mustela erminea), weasel (M. nivalis), polecat (M. putorius), American mink (M. vison), wildcat (Felis silvestris) and domestic cat (Felis catus). In the case of the domestic cat, questionnaire surveys quantified population sizes and predatory activity in rural, suburban and urban situations. Evidence of the former distribution of all the carnivores studied provides a credible historical basis for biodiversity action planning and the substantial archived database and bibliography provide further research opportunities.

Master of Science / Department of Biology / Craig Paukert / The North American river otter (Lontra canadensis) was extirpated throughout much of its range but is now recovering in many areas. Consequently, there is a need to determine river otter occupancy and habitat associations. We conducted sign surveys from January to April 2008 and 2009 in eastern Kansas to assess how local- and landscape-scale habitat affects river otter occupancy and how survey methods and habitat affect the detectability of river otter sign. Multiple observers surveyed 3-9 400-m stretches of stream and reservoir shorelines for 110 randomly-selected sites and measured local-scale (within a 100 m buffer of site) habitat variables (e.g., stream order, sinuosity, proportion of land cover types) and landscape-scale (Hydrological Unit Code 14 watershed) habitat variables (e.g., road density, shoreline diversity, proportion of land cover types). We then modeled occupancy and detection probability as a function of these covariates using Program PRESENCE. The overall probability of occupancy accounting for detection probability was 0.329. The best-fitting model indicated river otter occupancy increased with the proportion of woodland cover and decreased with the proportion of cropland and grassland cover at the local scale. The best-fitting model also indicated occupancy increased with decreased shoreline diversity, waterbody density, and stream density at the landscape scale, possibly because of the influence of large reservoirs in the watershed. Occupancy was not affected by land cover or human disturbance at the landscape scale, perhaps due to our relatively homogeneous study area or because river otters are habitat generalists. Detection probability for 400-m surveys was highest in mud substrates (p = 0.600) and lowest in snow (p = 0.180) and litter substrates (p = 0.267). Detection probability for scat was more than double that for tracks, and detection probabilities were 17-64% lower for novice observers than experienced observers. Detection probability also increased with survey length. Sign surveys are a useful technique for monitoring many species, including river otters, and accounting for detection probability will improve estimation of occupancy. Furthermore, understanding the ecological factors and the scale important to river otter occurrence will be useful in identifying areas for restoration and management efforts.

Marine vertebrate species face unprecedented and ever increasing pressures as a result of human activity, primarily fishing, in the global oceans. One area of growing concern has been for the impacts of small-scale fisheries on these species. Over the past decade it has become increasingly clear that these under-studied fisheries have sizeable levels of catch and bycatch of many threatened and endangered species of sea turtles, seabirds and small cetaceans. This thesis presents a collection of chapters that investigate aspects related to the interactions of small-scale fisheries with threatened marine vertebrates. We identify sizeable rates of bycatch of small cetaceans and seabirds for multiple small-scale longline and gillnet fisheries in both Peru and Ecuador. Catch rates of small cetaceans by the Peruvian small-scale driftnet fleet are estimated to exceed 10,000 dolphins and porpoises annually. A trial of acoustic alarms (pingers) in this same fishery showed a 37% reduction in small cetacean bycatch while not reducing target catch and represents a promising bycatch mitigation measure. Seabird bycatch was also found to be high in both longline and gillnet fisheries and included a wide range of seabird species including the critically endangered waved albatross (Phoebastria irrorata). Through post-capture satellite tracking of loggerhead turtles (Caretta caretta) we show that these turtles are present in pelagic waters off the coasts of Peru and Chile for extended periods during which they are at risk of repeat interactions with small-scale longline fisheries operating throughout their foraging habitat. Through scan and focal sampling of the endangered marine otter (Lontra felina) we also show that otters making den sites in human fishing communities face additional risks due to entanglement in fishing gear or interactions with feral animals but, if properly managed, these sites could serve as stepping stones for marine otters along the coast. The results presented here, gathered using a wide range of techniques, including onboard observer and shore-based monitoring, satellite tracking, bycatch quantification, and bycatch mitigation experiments, represent an attempt to better characterize and quantify the interactions of small-scale fisheries with threatened marine vertebrates toward identifying solutions that can lead to sustainable fisheries and populations of these protected marine species.

The Wing Trawling System (WTS) was tested as an alternative to traditional shrimp capture methods in the Gulf. Compared to an otter trawl, this trawl was conceived to reduce bycatch, retain shrimp catch, and minimize seafloor disturbance. Through seventy-one paired tows, the WTS was assessed against a standard otter trawl. The WTS was found to reduce bycatch by 63-65% and reduce shrimp catch by 30-35%. Additionally, I measured the depth of the scars produced by both trawls and quantified the turbidity of the plumes behind them. The scars left by the WTS and the otter trawl were between 9.9 cm-13.6 cm. The turbidity behind the WTS was 18.6 NTU, while the turbidity behind the otter trawl was 206.8 NTU. In conclusion, the WTS offers an alternative to an otter trawl that reduces bycatch and the impact trawling has on the seafloor but results in a significant amount of shrimp loss.

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains vi, 36 p. : ill. (some col.), col. maps. Includes abstract. Includes bibliographical references (p. 31-36).

Color vision can affect our assumptions of an animals’ natural history. It can be determined by testing sensory or perception ability, which was employed here. Two Asian small-clawed otters (Aonyx cinerea), of opposite sexes, housed at ZooAtlanta, were trained via operant conditioning to discriminate stimuli within 7 tasks, primarily in a two-choice fashion. Varying shades of the colors blue, green and red were tested against varying greys, all which differed in intensity, served as the stimuli for the first 4 tasks. The remaining 3 tasks, the colors were tested against each other. The male reached criterion for the first 6 tasks, indicating an ability to discriminate the stimuli based on color. The female however participated only in 2, and could not achieve criterion as set, though there were indications of discrimination ability. Taken together with sensory work on two related otter species, Asian small-clawed otters possess color vision.

This project describes a portion of a long-term study of the behavioral ecology of sea otters. Sub-studies of this project include the development of an individual recognition program for sea otters, the construction of male sea otter activity and energy budgets, and the assessment of male sea otter territory quality. The Sea Otter Nose Matching Program, or "SONMaP", was developed to identify individual sea otters in Simpson Bay, Prince William Sound, Alaska, using a blotch-pattern recognition algorithm based on the shape and location of nose scars. The performance of the SONMaP program was tested using images of otters collected during the 2002-03 field seasons, and previously matched by visually comparing every image in a catalog of 1,638 animals. In 48.9% of the visually matched images, the program accurately selected the correct image in the first 10% of the catalog. Individual follows and instantaneous sampling were used during the summers of 2004-06, to observe male sea otter behavior. Six behaviors (foraging, grooming, interacting with other otters, patrolling, resting, and surface swimming) were observed during four time periods (dawn, day, dusk, night) to create 24-hr activity budgets. Male sea otters spent 27% of their time resting, 26% swimming, 19% grooming, 14% foraging, 9% patrolling and 5% interacting with other otters. Field Metabolic Rate (FMR) was estimated by combining the energetic costs for foraging, grooming, resting, and swimming behaviors of captive otters from Yeates et al. (2007) with these activity budgets. "Swimming" accounted for the greatest percentage (43%) of energy expended each day followed by grooming (23%), resting (15%), feeding (13%) and other (5%). With a peak summer sea otter density of 5.6 otters km-2, the low percentage of time spent foraging indicates that Simpson Bay is below equilibrium density. Territory quality was assessed for male sea otters using four attributes: territory size, shoreline enclosure, accessibility, and number of females observed feeding in each territory. Each attribute was coded with a score of 0-2, and total quality scores ranged from 0.14-1.96 (0.9 + 0.61 SD). High quality territories had large areas, moderate shoreline enclosure, high accessibility, and many foraging females.

Sex differences in spatial cognition have been reported for many species ranging from voles to humans. The range size hypothesis predicts that sex differences in spatial ability will only occur in species in which the mating system selects for differential range size. Consistent with this prediction, we observed sex differences in spatial ability in giant pandas, a promiscuous species in which males inhabit larger ranges than females, but did not observe sex differences in Asian small-clawed otters, a related monogamous species in which males and females share home ranges. Furthermore, the sex difference in giant pandas was observed during the period of male range expansion and outside female estrus, thus the potentially confounding influence of decreased female ability was avoided. Finally, all subjects in this study were raised in captivity and never actually inhabited different range sizes. Therefore these findings emphasize the importance of biological rather than experiential factors underlying sex differences in spatial cognition. These results are the first evidence of sex differences in spatial ability in the order Carnivora, and provide support for the range size hypothesis.