Harry A. Jacobson

Antler measurements are used to set harvest restrictions for male white-tailed deer (Odocoileus virginianus) and to evaluate response to management. Remotely-triggered trail cameras are popular research and management tools, but have not been used to estimate antler size or age. We developed methods to estimate antler measurements and age of male deer â?¥ 1 year old from photographs. We developed predictive equations for individual antler measurements using photographs of mounted deer heads, and evaluated five anatomical features for potential use as a known-sized scaling reference in...

Quality deer management (QDM) advocates the protection of younger-age white-tailed deer (Odocoileus virginianus) bucks, but the subsequent survival of these animals remains unknown. We conducted a study to investigate the impact and importance of harvest and non-harvest mortality factors on adult male white-tailed deer in Mississippi on areas managed under QDM. We captured 408 deer and fitted 238 adult bucks with radio collars from February 1990 until January 1997. During the study, we documented 185 mortalities, which were used to estimate survival and cause-specific mortality rates....

Infrared-triggered cameras are increasingly used in wildlife management and require refinement for optimal use. We compared photographic recapture rates of tagged animals on two enclosed Mississippi study areas and a third enclosed study area in Oklahoma. We evaluated effects of camera density (one camera per 41 ha and one camera per 81 ha) and sampling duration (1 to 14 days) on accuracy of deer population estimates, cumulative new occurrences of adult males, cumulative sex ratio, and cumulative fawn crop on the Mississippi study areas. Photographic recapture rate varied from 92% for...

Historically, corpora luteal counts have been used to index reproductive output; however, there has been skepticism as to their usefulness in bobcats because bobcats may retain their corpora lutea from one season to the next. We conducted this study to determine if bobcats retain corpora lutea and if they are functional. Luteal bodies were monitored throughout multiple breeding seasons. The functionality of luteal bodies of previous cycles (LBPCs) in bobcats was explored using radioimmunoassay, and compared to that of corpora lutea (CL). LBCPs continued to produce progesterone, although CL...

We studied fawn survival during 1995 on Davis Island, Mississippi, an island in the Mississippi River. Newborn fawns were captured using line searches or vaginal implant transmitters. We captured 20 fawns with 8 surviving to 6 months. Cause of fawn mortality included coyotes (3) and natural mortality (2). Additionally, six fawns lost their transmitters and one transmitter failed. Overall survival rate of fawns to 180 days was 0.72. Male and female survival to 180 days was 0.66 and 0.78 respectively. Our results suggest fawn survival is not adversely affected by early summer flooding.

We recorded plant community characteristics in an 18-year-old, white-tailed deer (Odocoileus virginianus) exclosure in the Lower Coastal Plain of Mississippi during summer 1996. The 0.4-ha exclosure was constructed in 1977 within upland pine (Pinus spp.) forest of the Leaf River Wildlife Management Area in Perry County, Mississippi. Surveys at the time of exclosure construction revealed that similar plant cover and species richness existed inside and outside of the exclosure. Surveys were conducted during 1996 along 8 37-m transects located inside and outside the exclosure. Forest canopy...

We used infrared-triggered cameras to estimate white-tailed deer population size. The camera estimate simplifies analysis of photographs obtained from these cameras and provides an estimate similar to that generated using the models with program CAPTURE. Four surveys of an enclosed property in northeastern Mississippi generated counts of 16, 31, 40, and 14 antlered white-tailed deer using the camera estimate at different camera densities and at different time periods. Indentifying individuals by antler characteristics and analyzing the data using program CAPTURE estimated the population of...

Ages of 76 known-age white-tailed deer (Odocoileus virginianus) were estimated by tooth wear and replacement (TWR) and by incisor cementum annuli (CA) determination. TWR and CA methods gave similar results (75% and 71% correct, respectively). However, accuracy was dependent on deer age, with TWR being more accurate than CA in age classes <3.5 years and CA being more accurate in age classes >3.5 years. Accuracy of 55 southeastern United States biologists in estimating age of 98 known-age deer jaws also was determined. Results indicated biologists were well-skilled in the TWR technique...

Nine white-tailed deer (Odocoileus virginianus) outfitted with radio collars were observed for 9 months or longer to monitor seasonal movements and habitat utilization. Estimates of seasonal home-range size, using a multivariate method, varied from 176 ha to 1245 ha, and annual home range size varied from 455 ha to 2216 ha. Average annual home ranges of 4 females (737 ha ± 219 SD) was about half the average home range of 5 males (l511 ha ± 571 SD). Habitat utilization/availability analysis demonstrated significantly greater (P < 0.05) utilization of dense bottomland hardwood sawtimber...

Nine white-tailed deer (Odocoileus virginianus) outfitted with radio collars were observed for 9 months or longer to monitor seasonal movements and habitat utilization. Estimates of seasonal home-range size, using a multivariate method, varied from 176 ha to 1245 ha, and annual home range size varied from 455 ha to 2216 ha. Average annual home ranges of 4 females (737 ha ± 219 SD) was about half the average home range of 5 males (l511 ha ± 571 SD). Habitat utilization/availability analysis demonstrated significantly greater (P < 0.05) utilization of dense bottomland hardwood sawtimber...