Comments on Estimating Population Rate of Increase from Age Frequency Data

Although many papers have described assumptions and calculations of r from different kinds of data, none has compared estimates of r for the same real data set under different assumptions. We used the age distributions of gray foxes collected during six trapping seasons to estimate and compare r and lₓ series derived under different assumptions. Because trapped foxes are killed, they are believed by some to represent death history data. We found this treatment underestimates mortality so overestimates survivorship and leads to erroneous conclusions about the population. Use of a projection matrix allowed prediction of population size and thus allowed us to predict observed rate of increase. Use of projection matrices also resulted in the most conservative estimated of r

Cartographic Trend Analysis of Furbearer Harvest Distributions in Arkansas

Average by-county fur harvest for the last nine harvest seasons (1977-1985) was used as data points to be interpolated using nearest neighbor algorithms in computer-assisted trend analyses. COMPLOT maps were produced which represented a surface of harvest densities drawn over a map of Arkansas. Twelve furbearer species are examined, and topographic features of harvest density for each are interpreted in terms of ecology and/or buyer distribution. The trend surface technique removed some of the error inherent to harvest records, and produced an aesthetic graphical display of the information that was more easily interpreted and explained than other methods of analysis usually allow

Mensural Discrimination of the Skulls of Arkansas Peromyscus

Twelve parameters were measured on skulls of four species of Peromyscus from Arkansas. Univariate statistical tests, multivariate analyses of variance, and principal axis factor analyses were performed on the data set and/or subsets in a search for species-level discriminating characters. Total length of skull was found to discriminate between skulls of P. maniculatis, P. leucopus, and a combined group of P. attwateri and P. gossypinus. Furthermore, the ratio of interorbital width and length of nasal bone was found to adequately discriminate between skulls of P. attwateri and P. gossypinus

Dental Pathology in Selected Carnivores from Arkansas

The occurrence and kinds of dental pathology in wild carnivore populations in Arkansas were investigated through examination of 1295 skulls of bobcat (Felis rufus), river otter (Lutra canadensis), gray fox (Urocyon cinereoargenteus), coyote (Canis latrans), and raccoon (Procyon lotor). Pulpitis or abscesses in broken or otherwise exposed teeth were noted in all species, but bobcats had the fewest exposures while otter and gray foxhad the most. Osteomyelitis occurred in all species except the bobcat. Caries were noted in the coyote, raccoon, and gray fox. Otter and coyote had alveolar thinning, and coyote had enamel dysplasia and maxillary sinusitis

Analysis of the Fall and Winter Diet of the Bobcat in Eastern Arkansas

Food habits of the bobcat (Felis rufus) in eastern Arkansas were examined based on stomach contents of 148 specimens. Rabbits (Sylvilagus floridanus and S. aquaticus) were the primary food source for males, females, and kittens. Rice rats (Oryzomys palustris), nutria (Myocastor coypus), and several species of waterfowl are first reported as food of bobcats in Arkansas. Cotton rats (Sigmodon hispidus) and muskrats (Ondatra zibethica) were more common in bobcat diets in eastern versus western Arkansas. Adult males did not use smaller prey but this food source was common, in kittens; females were intermediate in their use of smaller prey

Harvest Trends of the Bobcat (Felix Rufus) in Arkansas

Arkansas bobcat fur harvest records were examined in relation to forest cover, furbuyer distribution, and price. Availability of forest cover correlated with areas of greatest harvest, and a dynamic forest products industry in southern Arkansas is believed to support a greater density, and therefore greater harvest, of bobcats. Comparison of furbuyer distribution with harvest level among physiographic regions suggested that the fur industry in southern Arkansas could expand. Prices increased dramatically in the 1970\u27s, and 94.5% of the variation in harvest level could be explained by price