The main subject of my papers has been the phylum Tardigrada, with particular emphasis on the Antarctic fauna. While this is one of the ‘lesser known phyla’ the group forms an important element of Antarctic non-marine ecosystems. My work has centred on four interrelated themes: i) taxonomy, predominantly Tardigrada and with an Antarctic bias though including wider global species and high taxon groupings (I have also worked on other taxa such as Fungi-imperfecti and freshwater invertebrates); ii) biodiversity of tardigrades, particularly Antarctic habitats; iii) data-based studies based on the terrestrial Tardigrada and Antarctic freshwater crustaceans; and iv) biogeographic analysis of these databases. The thesis presented consists of papers published in major, peer-reviewed journals, along with book chapters published and in press. Several of my papers have been cited 10-30 times according to the ISI Web of Science citation system. Highlights of my work include being the first to publish a paper on the global terrestrial biogeography of a phylum and showing the extant limno-terrestrial tardigrade fauna reflect the early tectonic break-up of the Laurasia, West and East Gondwana super continents between 65 and 135 million years ago.

Polar bears (Ursus maritimus) are experiencing rapid and substantial changes to their environment due to global climate change. Polar bears of the southern Beaufort Sea (SB) have historically spent most of the year on the sea ice. However, recent reports from Alaska indicate that the proportion of the SB subpopulation observed onshore during late summer and early fall has increased considerably. Previous research suggests that the number of polar bears onshore is linked to sea ice conditions and the availability of subsistence-harvested whale carcasses, which are referred to as bone piles. My objectives were to determine the development and fitness consequences for SB polar bears that come onshore. Furthermore, I aimed to reveal the number of polar bears that come onshore and feed at whale carcasses. I used a combination of genetic and behavioral data collected on SB polar bears from 2010-2013 to determine if onshore behavior developed through genetic inheritance, asocial learning, or social learning. I found that onshore behavior was primarily transmitted via mother-offspring social learning. I used hair samples collected at bone piles near Kaktovik, Alaska from 2011-2014 and genetic capture-recapture techniques to estimate the annual number of polar bears that visited the bone piles and rates of apparent site fidelity to the bone pile. I estimated that as many as 146 (SE = 21) SB polar bears visited the bone piles near Kaktovik in 2012. Annual rates of apparent site fidelity to the bone pile for male polar bears ranged from 0.60 (SE = 0.07) to 0.61 (SE = 0.07), and female rates of apparent site fidelity was 0.69 (SE = 0.19). Lastly, I used quantitative fatty acid signature analysis to estimate the proportion of bowhead whale, ringed seal, bearded seal, and beluga whale in the diets of SB polar bears from 2004-2015. I revealed that polar bears achieved higher body condition by coming onshore and feeding at whale carcasses. Overall, my results indicated that SB polar bears are socially learning from their mother to come onshore and that this behavior is linked to increased body condition.

The social behavior of brown bears (Ursus arctos) was studied during the summers of 1972 and 1973 as bears fished for salmon at McNeil River, Alaska. Study objectives were to determine behavioral characteristics of bears in relation to sex and age, changes in social behavior over a 40-day long fishing season, social and environmental parameters correlated with the occurrence of behavior, and to test the hypothesis that brown bears modify social behavior in a feeding aggregation to exploit a resource limited in time and space. Over one-half of the agonistic interactions consisted of passive deferrals. Encounters that included elements of overt threat were jawing, sparring, charges, and fighting. Jawing was the most prevalent agonistic encounter and generally occurred between individuals of the same sex and age class. Sparring, charges and fights were generally initiated by larger bears against smaller individuals. Females with young were most intolerant. Adult males participated in few encounters that involved overt threat since most bears avoided them. Single adult and adolescent females were neither particularly aggressive nor especially tolerant. Adolescent males adjusted quickly to McNeil Falls and as a group were unaggressive. Subadults were wary and frequently were the objects of aggression of older bears. Social dominance relationships between bears of the same class were often ambiguous, the exception being adult males. Relationships between bears of different classes were mostly stable; adult males were dominant, followed in order by females with young, single adult females, adolescents, and subadults. However, apparent reversals also were common between single adult females and adolescent males. Nonagonistic encounters occurred only when salmon were exceptionally abundant and usually involved adolescent and subadult bears. Behavioral changes over time included a decline in the frequency of running deferrals, a decline in deferrals in total, and a decline in the frequency of charges. The occurrence of fighting and sparring encounters did not change, but the frequency of jawing increased within each fishing season. Various factors determined salmon caught by a bear per hour of fishing effort: salmon abundance, water levels, time of day, and fishing location. The time of day a bear could fish and its choice of location depended on its ability to gain and defend a profitable site. Fishing success was directly correlated with social status, but differences in success are probably unimportant in terms of individual fitness except when salmon are relatively scarce. Changes in encounter intensity over time had no detectable effect on fishing success. Salmon abundance, however, resulted in a further reduction of agonistic encounter intensity and an increase in nonagonistic encounters. Bear social relationships were governed largely by variations in resource abundance. Despite energetic and psychological costs imposed by the bear concentration on individual animals, salmon were evidently sufficiently numerous that these costs were outweighted by returns in protein. Dominance relationships at McNeil Falls did not correspond to predictions of classical dominance theory. This may have been partially attributable to the fact that bears in aggregations derive no benefits from tacit acceptance of subordinate roles; a bear's alternatives were to compete and gain access to food or, if unsuccessful, to try elsewhere. To pose the question if normally solitary bears can adapt behaviorally to efficiently exploit a localized source of food may have been inappropriate. Alternatively, bears can be viewed as occupying and defending areas akin to small territories, with their behavior explicable in terms of energetic costs and benefits based on variations in resource abundance.

Understanding energetic potential of habitat patches is important for management designed to provide adequate habitat for wildlife species. Great Smoky Mountains National Park (GSMNP) has a high density of black bears that have been studied intensively from 1968-1997; habitats within the Park are relatively undisturbed, and similar vegetative cover types can be found throughout the southern Appalachian mountains. Black bear reproduction in the Park has been correlated to hard mast production, however little work has been done to assess the importance of soft mast. Geographic Information System (GIS) based habitat use models have been developed for bears in the Park, yet the importance of foods in determining habitat selection, and the possibility of sexual habitat segregation due to food availability have not yet been determined. The primary objectives of the study included estimation of the location, timing, and amount of caloric production by 19 important black bear foods and determination of the significance of caloric production by mast type, season, overstory vegetation type, and plant species. Secondary objectives were to test for correlation of bear habitat use with estimated caloric production from mast, and to test for sexual segregation of habitats based on caloric production. This study was limited to the northwest quadrant of GSMNP during 1995.

The benefits gained by the presentation of environmental enrichment (EE) to captive animals are widely recognized. Few studies have, however, studied how to maximize the effect of EE. Repeated presentations of EE may cause a reduced interest towards the EE device, called habituation. To study the effect of habituation towards EE, behavioural data from 14 captive Sloth bears (Melursus ursinus) were collected during two different EE treatments. In treatment one, honey logs were presented for five consecutive days (ConsEE). In treatment two, the logs were presented every alternative day for five days (AltEE). The different treatments both showed a significant effect on responsiveness toward the EE, however, leaving gap days inbetween presentations in AltEE showed no reliable reduction in habituation. Both treatments significantly reduced stereotypies, however, only ConsEE reduced levels of stereotypies long term. Explorative behaviours, which are the most prominent behaviours in the wild, increased during both treatments. This is consistent with previous findings (Fischbacher & Schmid 1999, Grandia et al. 2001) that EE increases natural behaviours, which has been desribed as an indication of improved welfare (Carlstead et al. 1991 etc.). Other behavioural categories such as social and passiva behaviours were unaffected by the EE presentations. THe results show that it is possible to increase the effectiveness of EE by simple means in order to ensure animal welfare.

For the polar bear (<i>Ursus maritimus</i>), a terrestrial carnivore on the highest trophic level in the Arctic marine ecosystem, periods of nutritional restriction or fasting are a characteristic feature of an annual cycle. The overall objective of my thesis was to examine some of the effects of such a 'feast-or-fast' feeding pattern on the body composition, body size and reproductive performance of this Holarctic ursid. As a reproductive strategy, pregnant polar bears occupy maternity dens for up to 6 months between late summer and spring. While in dens, maternal nutrient stores meet all maintenance energy requirements and sustain the nutritional demands of gestation and early lactation. I quantified the nutritional costs of this prolonged 'reproductive fast' in polar bears and examined the effects of variation in maternal body condition on reproductive performance. While fasting, body mass decreased by 43% and of the change in body energy content 93% was attributable to loss of fat. Bears that were fatter priorto denning produced heavier cubs, which would be more likely to survive. Much of the variation in body condition prior to denning was accounted for by age, older females being in better condition. Using an index of milk quality that was closely related to daily milk energy yield, I investigated the independent effects of maternal body condition and age on lactation. Irrespective of condition, older bears tended to produce higher quality milk. While lactation in polar bears is clearly sensitive to body condition, these results also provide strong support for an age-specific increase in reproductive effort among females. Body size is typically a strong determinant of male reproductive success in polygynous mammals such as polar bears. Consequently, theory predicts that mothers in good condition should invest more in male than female offspring in-order to produce large adult males. An underlying assumption of this theory, however, is that early differences in body size among male offspring, such as those apparent by the end of maternal care, will affect their relative adult body size. I tested the validity of this assumption in polar bears and found that, in comparison to females, variation in body size among 2-year-old males was a weak determinant of adult size. I suggest that, in comparison to females, a longer period of growth after maternal care may predispose the adult size of males to a greater degree of environmentally mediated variation. This lack of persistence in relative body size would limit the ability of mothers to affect the adult size of their male offspring, and thus reduce the effectiveness of sex-biased maternal investment as a reproductive strategy in polar bears. One of the principle physiological adaptations enabling animals to go without food for prolonged periods seems to be a heightened ability to minimize the net catabolism of body protein. I quantified changes in the body composition of free-ranging polar bears during the ice-free season. In contrast to previous studies on fasting bears, catabolism of protein appeared to meet a significant proportion of maintenance energy demands in some individuals. (Abstract shortened by UMI.)

The principle objective of this investigation was to develop an understanding of the biochemical and physiological response of free-ranging adult polar bears (<i>Ursus maritimus</i>) to prolonged fasting. A body condition index was developed from two measures, total body mass and straight-line body length, and was used as a covariate in the analyses of all other data. Protein and amino acid catabolism and urea synthesis were significantly lower in fasting bears when compared to feeding bears, and in fat bears when compared to lean bears. The inference from these results is that the energy metabolism in both states (fasting and fat) is one in which lipid is the predominant fuel for energy and nitrogen is conserved. Nutritional state (feeding versus fasting) had no significant effect on the plasma concentrations of non-esterified fatty acid, glycerol, and ketone bodies, or on the plasma ratio of acyl-carnitine to free carnitine. Furthermore, acetoacetate concentration was below the level of detection (<196 [mu]mol/L) in all bears, and â-hydroxybutyrate concentration never exceeded 291 [mu]mol/L. These results suggest polar bears are able to regulate closely the synthesis, release, and use of lipid metabolites without significant alteration in their plasma concentrations. Fasting polar bears showed no evidence of essential fatty acid (EFA) deficiency; the proportions of the diet-derived EFA linoleic (18:2[omega]6) and á-linolenic (18:3[omega]3) acids in the plasma and adipose tissue of fasting polar bears were greater than that in feeding polar bears. Plasma triiodothyronine concentrations and rectal temperatures were lower in fasting bears captured during summer-fall than in feeding bears, which suggests metabolic rates were decreased during fasting to conserve body fuels. Liver glycogen concentrations were found to be higher in fasting polar bears than in feeding bears. Furthermore, the results from intravenous administration of glucose (glucose tolerance test) to polar bears indicated the rates of insulin secretion and clearance in polar bears were slow relative to rates reported for other mammals. The inference from these results is that polar bears are not as dependent on glucose for energy as are other mammals and, as a consequence, are more lax in regulating their body glucose stores.

<p>The benefits gained by the presentation of environmental enrichment (EE) to captive animals are widely recognized. Few studies have, however, studied how to maximize the effect of EE. Repeated presentations of EE may cause a reduced interest towards the EE device, called habituation. To study the effect of habituation towards EE, behavioural data from 14 captive Sloth bears (<em>Melursus ursinus</em>) were collected during two different EE treatments. In treatment one, honey logs were presented for five consecutive days (ConsEE). In treatment two, the logs were presented every alternative day for five days (AltEE). The different treatments both showed a significant effect on responsiveness toward the EE, however, leaving gap days inbetween presentations in AltEE showed no reliable reduction in habituation. Both treatments significantly reduced stereotypies, however, only ConsEE reduced levels of stereotypies long term. Explorative behaviours, which are the most prominent behaviours in the wild, increased during both treatments. This is consistent with previous findings (Fischbacher & Schmid 1999, Grandia et al. 2001) that EE increases natural behaviours, which has been desribed as an indication of improved welfare (Carlstead et al. 1991 etc.). Other behavioural categories such as social and passiva behaviours were unaffected by the EE presentations. THe results show that it is possible to increase the effectiveness of EE by simple means in order to ensure animal welfare.</p>

Understanding energetic potential of habitat patches is important for management designed to provide adequate habitat for wildlife species. Great Smoky Mountains National Park (GSMNP) has a high density of black bears that have been studied intensively from 1968-1997; habitats within the Park are relatively undisturbed, and similar vegetative cover types can be found throughout the southern Appalachian mountains. Black bear reproduction in the Park has been correlated to hard mast production, however little work has been done to assess the importance of soft mast. Geographic Information System (GIS) based habitat use models have been developed for bears in the Park, yet the importance of foods in determining habitat selection, and the possibility of sexual habitat segregation due to food availability have not yet been determined. The primary objectives of the study included estimation of the location, timing, and amount of caloric production by 19 important black bear foods and determination of the significance of caloric production by mast type, season, overstory vegetation type, and plant species. Secondary objectives were to test for correlation of bear habitat use with estimated caloric production from mast, and to test for sexual segregation of habitats based on caloric production. This study was limited to the northwest quadrant of GSMNP during 1995.

Thesis (M.F.A.)--University of New Orleans, 2003. / Title from PDF title page (viewed on Apr. 5, 2005). "A thesis ... in partial fulfillment of the requirements for the degree of Master of Fine Arts in the Department of Drama and Communications." Vita. Includes bibliographical references (p. 72-93).