Seasonal population fluctuations of the cottontail rabbit were measured by evening roadside counts and trapping. During the latter part of July, roadside counts showed a rather marked and drastic decline in the number of rabbits. This decline was forecast by the low number of rabbits seen in the field and the low number of rabbits the investigator was able to trap. Further confirmation of this decline came during the first week of the 1960-61 hunting season. A 42 per cent decrease in the number of rabbits killed occurred in spite of a 10 per cent increase in hunting pressure. By the end of the hunting season a 60 per cent decrease in the rabbit harvest was recorded. / Master of Science

This study, conducted at Camp Pickett, Virginia, attempted to evaluate several rabbit management practices currently in use on this deactivated military reservation. The methods being applied by the Virginia Come mission of Game and Inland Fisheries consist of establishment of wildlife food plots, the seeding of fire lanes and mowing and burning as a means of retarding ecological succession. Results of these evaluations indicated that the annual mixture plot is the type most heavily utilized by rabbits during the fall. Next in importance was the clover-winter grain combination planting. These conclusions were determined by means of live trapping and these trapping data were substantiated by pellet counts. A total of 211 rabbits were handled in this phase of the study; 135 were marked and 76 were recaptured. Of the 135 animals marked, 40.8 per cent were marked in the annual mix plots. This trapping demonstrated a sex ratio of 130 males to 100 females and an immature to adult female ratio of 2.3:1. A relationship between trapping success and temperature seemed to exist; a coefficient of correlation of -0.273 was calculated. A vegetative inventory inferred that both mowing and burning may be desirable rabbit management practices. An attempt was made to test three population estimation formulae on a known, enclosed rabbit population. Results of trapping within the five acre enclosure gave a comparable population estimate fer the Lincoln index, the Krumholz formula and the Schumacher-Eschmeyer formula. This experiment was not carried to the refined point of supplying definite conclusions; further investigation is necessary before concrete recommendations may be made. Records of the hunting season harvest were maintained. When these kill figures were combined with a rough estimate of the rabbit population on Camp Pickett, it was indicated that approximately 26 per cent of the cottontails were harvested. Hunting kill records maintained by the Game Commission over the past three years show a marked increase in hunter success, probably due te the effects of management. All bot fly parasitism cases were noted; 155 infestations were observed among the 325 rabbits handled. The larvae demonstrated no preference as to sex of the host but immature cottontails were more heavily parasitized than were adults, Records of tularemia incidence throughout Virginia have been maintained. Two areas of greater incidence occur; however, the Camp Pickett area appears to be average for the state. Cost comparisons were made between annual mix plots and clover-winter grain plots. The annual mix type of food plot cost an estimated $7.30 per half acre te install; the clover plot cost $18.09 per half acre. Which type plot, annual or perennial, is used depends upon the budget and Labor available. The writer favors use of the clover plots for rabbits both from the economical and biological points of view. / Master of Science

This study, concerned with evaluation of Cottontail Rabbit management techniques, was conducted at Camp Pickett, Virginia, a 47,000-acre deactivated military reservation. This public hunting area is managed cooperatively by the U. S. Second Army and the Virginia Commission of Game and Inland Fisheries. Cottontail Rabbit population fluctuations were measured by roadside counts during the summer months. It was found that a precipitous drop in the rabbit population occurred in mid-August. The suspected etiology of this population drop was disease, although no research data were collected to substantiate this theory. Land-cultural treatments were calculated by means of pellet counts and live-trapping. The treatments extant on Camp Pickett are installation of annual game bird mix and clover-small grain food patches, seeding of firelanes in fescue and clover-fescue combination, burning and mowing. Summer pellet counts showed the rabbit to be utilizing the annual mix food patches more than any other treatment type. The clover-small grain food patch was next in preference. Utilization of the remaining treatment types, which were mostly located in forested area, was rather low. Fall trapping data revealed a switch to the clover-small grain management unit, with the annual mix running second. Utilization of the other treatment types was again low. Winter trapping data showed an even greater preference for the clover-small grain than was found in the fall. Spring pellet count data resembled that obtained in the previous summer, with the exception of the burned areas, which received substantial usage by the rabbit. Differences between spring pellet count data and winter trapping data are believed due to an accumulation of older pellets. A pellet durability study showed winter loss of pellets to be minimal. An attempt to evaluate various population estimation formulae by live-trapping a known cottontail population in a five-acre enclosure met with failure when deer knocked down the fence, hunters poached, and rabbits were lost from various other causes, often unknown. A record was kept of all parasites, disease and injury encountered in the rabbit population. Forty-two per cent of all rabbits handled either were or presented evidence of having been infested with bot fly larvae. An incidence of 2.2 per cent of Shope's fibroma was found. A record was kept of all cottontail deaths known to have been caused by motor vehicles. The number of deaths per mile of highway traveled became progressively higher through the months of July to April, even though the rabbit population became progressively lower. This increasing highway kill was apparently due to the increased movement required of the rabbit in the winter months when food and cover are scarce, and the increased movement that occurs among the rabbit population when the spring breeding season arrives. / Master of Science