Inaug.-dis.--Heidelberg. / Lebenslauf. "Anhang. Verzeichnis der mittleren örter von 88 fixsternen für 1900.0": p. [55]-63.

Grizzly bear (Ursus arctos) den-site selection may be influenced by multiple factors at varying spatial extents. To test for hierarchical selection, I compared grizzly bear den sites (n = 21) to random locations in the Southern Lakes, Yukon at two scales: mesoscale (within 1 km of dens) and microscale (within 100 m of dens). I observed selection for den opening slope, pixel slope, soil content, and horizontal cover at the mesoscale. At the microscale, I observed selection for opening slope and horizontal cover. To further test the role of security and the sex hypothesis of sexual segregation, I compared adult female (n = 142), adult male (n = 36), and juvenile (n = 35) den locations in Denali National Park and Preserve, Alaska. Adult females spatially segregated from adult males, with dens characterized by higher elevations and steeper slopes than adult male den sites.

Bands of domestic sheep lambing on the open range in south central Wyoming were monitored for predator losses prior to and following coyote (Canis ·1atrans) removals. Experimental treatments, including 1) no removal (control), 2) removal of 2 adults and their pups, and 3) removal of pups only, were replicated 15 times each. Number of predation incidents (events) was reduced 98.2% by removing adults and pups. The number of sheep killed was reduced by 98.8%. Removing only litters of pups resulted in a decrease of 87.7% total kills decreased 91.6%. in predation incidents, while Overall, 23 of 30 predation sequences terminated immediately, while in all cases predation ceased within 3 days after removing adult coyotes and/or their pups. In terms of "offending individuals", denning can be a very selective means of coyote depredation control. The data suggest that removing only litters of offending adults can be nearly as effective in stopping losses as removing the adults. Biological parameters such as litter size did not appear to influence kill frequencies. A cost-effectiveness analysis was calculated.

The late Pleistocene faunal assemblage from Bat Cave, central Ozarks, Missouri provides an opportunity to assess specific aspects of behavior, ecology, and ontogeny of the Rancholabrean species Platygonus compressus. All identifiable elements referable to this taxon were catalogued and examined, and a minimum number of individuals of 73 was determined for the sample. Evidence of seasonal behavioral patterns are reported for the first time in a fossil peccary. Maturation of individuals was assessed using the tooth eruption sequence and occlusal wear patterns for all tooth-bearing mandibular elements and isolated lower dentition. Approximate ages were established through comparison with the extant collared peccary. The presence of distinct, developmentally non-overlapping age groups suggests that P. compressus was seasonally present at the Bat Cave locality, with the cave functioning as seasonal shelter in which individuals would occasionally die. The study also suggests the peccaries engaged in synchronous, seasonal breeding behaviors. Demographic assessment of the Bat Cave peccary population suggests that younger individuals formed the bulk of the population at a given time with progressively older individuals becoming scarcer until the age of about 10 years, which matches the typical demographic patterns and life expectancy of extant peccaries.

The Cooperative Alleghany Bear Study (CABS) was initiated in 1994 by the Virginia Department of Game and Inland Fisheries (VDGIF) and the Virginia Polytechnic Institute and State University (VPI&SU) to investigate population dynamics on Virginia's hunted bear population. CABS personnel handled 746 different bears (1.5M:1F) 1,368 times on its northern study area during June 1994 to September 2000. The sex ratio for summer captures was 1.5M:1F, which differed from 1:1 (n = 1,008, Z = 6.17, P < 0.0001). Sex ratios for the summer captures ranged considerably among years (÷2 = 23.92, df = 6, P = 0.0005) and among age classes (÷2 = 119.22, df = 4, P < 0.0001), with the largest discrepancy among yearlings (5.7M:1F). The sex ratio among captured adults favored females (0.6M:1.0F ). Average age for all captured bears was 3.87 ± S.E. 0.12 years; females (n = 309) averaged 5.20 ± S.E. 0.16 and males (n = 402) averaged 2.84 ± S.E. 0.14 years (t = 10.92, df = 709, P < 0.001). Litter size averaged 2.35 cubs / litter over the 6-year period and sex ratio did not differ from 1:1 (n = 183, Z = 0.74, P = 0.461), but varied among years (÷2 = 16.61, df = 5; P = 0.005). Three-hundred-and-seventy-six (164M, 212F) of 746 captured individuals were equipped with radio-transmitters. The ratio of radio-collared bears fluctuated from 2.6 F:1M (1998) to 8.6F:1M. We tested a radio-collar effect on survival as a covariate and found a significantly higher survival for radio-collared adult and 3-year-old females in the first 3 years of the study (c2 = 6.64, 1 df, P = 0.01). Estimates using the Kaplan-Meier staggered entry showed survival rates for females (adults = 0.993, subadults = 0.997) higher than for males (adults = 0.972, subadults = 0.917). Estimates using the mark-dead recoveries data showed survival rates of 0.840 for adult females (0.714 for 2-year-olds) and 0.769 for adult males (0.335 for 2-year-olds). We observed 34 mortalities of radio-collared bears for which hunting mortality accounted for 85%. Four natural mortalities included a 5-year-old female and a 2-year-old male that were killed by other bears, and a 14-year-old and 2-year-old female that died of unknown causes. Among the ear-tagged sample, 2-year-old males experienced the highest mean harvest rate of 45%, with a high of 65% mortality in 1996. Among females, 2-year-olds were most vulnerable with a harvest mortality rate of 22% a year. Population modeling indicated that population growth rate of black bears in Virginia is most sensitive to changes in adult female reproduction and survival. With current survival and reproductive estimates, simulation indicated that adult female harvest has to increase 44% from current levels to stabilize population growth. Population size estimates using Bowden's estimate for mark-resight data for a 100 km2 sub-area on the northern study area ranged from 83-131 animals during 1998-2000. When adjusted for the proportion of time radio-collared bears spent on the study area population estimates fell to 63-96 bears. Using the Lincoln-Petersen estimate with Chapman's modification, black bear population estimates for the northern study area ranged from 582-1,026 animals during 1994-1999 on the 860 km2 area. Visitation rates to bait station sites correlated well with changes in population size estimates (n = 5, r = 0.97, P = 0.007). Black bear harvest in general was weakly correlated to change in population size (n = 6, r = 0.49, P = 0.328), however, archery harvest was highly correlated (n = 6, r = 0.95, P = 0.002). The monitoring indices showed all showed the same trends. We recommend a combination of them rather than relying on only a single index for monitoring Virginia's black bear population. During winters 1995–2001, located 215 dens of radio-collared bears; 68% were in trees. Ground dens used by bears included nests in laurel thickets, excavations, brush piles, and rock cavities. The proportion of bears using tree dens did not differ between our 2 study areas (n = 203, ÷ 2 = 1.63, 1 df, P = 0.202), the proportion of females using tree dens (65%, n = 127) was greater than that of males (33%, n= 15; ÷ 2 = 10.69, 1 df, P < 0.001) on the northern study area. Sex and age were significant factors in determining the type of den a bear selected. Twenty-six of 66 individual bears handled for 2–6 consecutive years consistently used tree dens, 8 were faithful to rock cavities, and only 4 regularly used ground dens for denning. Twenty-eight bears (42.4%) switched den types over the 6–year period, primarily from tree dens to rock cavities. / Ph. D.

Knowledge about a species’ reproductive parameters such as breeding behaviours is a vital building block for essential conservation actions, especially for endangered species. Despite this, there is a considerable knowledge gap about the snow leopard (Panthera uncia) maternal behaviours, as well as the timing of den independence for the cubs. It has been assumed that female snow leopards change their behaviours post-denning and that the cubs leave their den together with their mothers around two to three months of age. However, until this day no quantitative data has been used to analyse female behaviours post-denning and when the cubs leave their den. I analysed pre- and post-denning activity for seven GPS-collared snow leopard females in Tost Mountains of southern Mongolia during the years 2010 to 2019. With linear mixed models and generalized linear mixed models, I found that female snow leopards with small cubs changed their behavioural patterns and space use by decreasing their monthly home range size, compared to females with older or no cubs. When the cubs became six months old, there were no detectable differences in these behaviours which suggests that the cubs started to travel continuously with their mother at the age of 5-6 months. The rate at which the collars successfully acquired positions decreased considerably during the early phase of denning when the female spent considerable time at the den sites where the collars could not communicate with the satellites. The age of the cubs when the female left the den ranged from 21-61 days (mean =44 days), suggesting that snow leopard females use their dens for 1.5 ± 0.5 months. This study provides the first estimate of the extent of den use by snow leopards, as well as the first estimates of post-denning behavioural patterns for snow leopard females and their cubs.

During 1994-1996, reproductive biology and denning ecology of black bears (<i>Ursus americanus</i>) were investigated in the George Washington and Jefferson National Forests, Virginia. The average age of captured bears was 4.88 years (SE=0.43, n=64) and 2.72 years (SE=0.19, n=127) for females and males, respectively. Timing of estrus ranged from 21 June to 7 August with most (58.8%, n=10) estrus females captured between 15 July and 31 July. Ages of primiparity were 3 or 4 years and averaged 3.14 years (SE=0.14, n=7). Average litter size was 2.0 cubs per litter (n=26). During 1995 and 1996, respectively, 81.8% and 83.3% of potentially pregnant females reproduced. Date of parturition averaged 22 January in 1995 and 1996, but ranged from 1 January to 22 February in 1995 and 11 January to 14 February in 1996. Pregnant females did not enter dens earlier (T=0.74, P=0.4598) than other bears, and did not emerge later (T=-1.69, P=0.0925) than other bears. cavities in trees and snags composed 82.4% (n=56) of all dens. Red oak (<i>Quercus rubra</i>) and chestnut oak (<i>Quercus prinus</i>) were the most commonly (n=49) used den tree species. Tree dens were on sites with steeper slopes (t=3.41, P=0.0013), lower medium tree density (t=-2.22, P=0.0313), higher large tree density (t=2.24, P=0.0296), and lower stem density (t=-3.43, P=0.0013) than random sites. Ground dens were on steeper slopes t=3. 22, P=O. 0122) than random sites. Den reuse occurred at 2 of 17 (11.8%) dens, and 84.6% (11 of 13) of bears, monitored both winters, used the same den type during both winters. Virginia's black bear harvest during 1982-1994 was used to reconstruct Virginia's bear population. During 1982-1991, Virginia I s reconstructed male black bear population ranged from 880 bears to 1,241 bears. Numbers of males increased during 1982-1986, declined during 1987-1989, and increased during 1990-1991. Virginia's reconstructed female black bear population ranged from 943 bears to 1064 bears and increased most years. / Master of Science

During 1999-2001, potential den trees and denning success of black bears was investigated on industrial forest lands and national forest lands in Virginia and West Virginia. One hundred and fifty seven potential den trees were found on five study areas, 135 on national forest lands and 22 on the industrial forest lands. Twenty-seven hollow potential den trees were found, 22 on national forest lands and 5 on industrial forest lands. Densities of potential den trees ranged from 12.5/km2 to 437.5/km2 on the national forest lands and on the industrial forest lands the densities ranged from 0-187.5/km2. There were significantly higher densities (F1, 69=5.86, P=0.0181) of potential den trees on the national forest land than on the industrial forest land. There were also significantly (F=2, 68=7.86 P=0.0008) higher densities of hollow potential den trees based on the stand age class. Denning success for females expected to have cubs was 98% (n=46) in tree dens on national forest lands and 100% (n=8) on industrial forest lands. Denning success for females expected to have cubs was 76% (n=55) in ground dens on national forest lands and 80% (n=5) in ground dens on industrial forest lands. Females expected to have cubs on the national forest lands had an overall denning success of 89% (n=80) and on industrial forest lands there was overall, 92% (n=13) denning success. Chi-square tests showed that abandonment of dens by bears was significantly higher (x2=19.02, 1df) in ground dens than in tree dens. Litter sizes were not different from national forest lands and industrial forest lands (t=-0.36, 44df, P=0.84). The mean litter sizes on the national forest lands was 2.55 (SE=0.16) cubs per litter and on the industrial forest land 2.4 (SE=0.22) cubs per litter. / Master of Science

Human disturbance as the main factor influencing the habitat of brown bear (Ursus arctos) has occurred frequently with the development of human society. How to reduce and prevent the conflict between human and brown bears is considered as an important question for brown bear conservation, management and public safety. Sånfjället National Park has one of the densest bear populations in Sweden. Many tourists are attracted to visit bears each year. Through this study, the most possibility brown bear denning habitat in Sånfjället National Park was determined by using Multi-Criteria Analysis. A customized habitat distribution map generator was programmed within the Microsoft Visual Basic® for Applications (VBA) in ArcGIS. Three themes were designed in the map generator, i.e., the human impact emphasis weighted, neutral weighted themes and customized weighted theme. Customized weighted theme was produced for user discovering denning habitat results with user-defined weights. Comparing the final maps generated from the human impact emphasis weighted and neutral weighted themes, human influence concentrated in the south area of the National Park. The trails near Sveduterget should be changed to avoid human disturbance in the bear denning period.

Diseases that infect wildlife populations pose a significant threat to public health, agriculture, and conservation efforts. The spread of these diseases can be influenced by the social structure of the population, and therefore often need to be accounted for in disease models. In this thesis I use high-resolution contact data to explore the social structure of a high-density population of European badgers (Meles meles). I explore how this structure might influence the spread of bovine tuberculosis (bTB), a debilitating disease of cattle for which badgers are a wildlife reservoir. Denning and home range data collected using radio tracking is also used to determine how this social structure is related to badger space use. I use social network analysis to identify the community structure of the badger population, revealing that badgers interact in fewer, more distinct groups than previously assumed. This is likely to inhibit the spread of disease through the population, given that the probability of infection entering a new social group will be reduced. However, among-group contact is still found to occur even between the most isolated groups. I show that this among-group contact is more likely to occur between less related individuals, possibly suggesting that breeding behaviour may drive among-group contact as a mechanism for inbreeding avoidance. To gain additional insight into this among-group contact, I determine how badger spatial behaviours are related. I show that the use of dens (setts) away from the social group’s main sett (outlier setts) in the spring is associated with extra-territorial ranging. I also show that this extra-territorial ranging is associated with more central network positions. The seasonality of this behaviour further suggests that this may be related to breeding activity. These findings suggest that behaviours associated with extra-group ranging may increase the risk of acquiring and transmitting infection. Therefore, use of outlier setts in the spring could act as a spatial proxy to identify high-risk individuals for disease spread, offering potential targets for disease control. Finally, I discuss the implications of these findings in regard to what they reveal about badger behaviour, disease transmission, and the design of effective disease control strategies. The importance of understanding population social structure for the study of wildlife disease in general is also discussed.