Jason R. Boulanger

Biochemical Variables in Free-ranging White-tailed Deer (Odocoileus virginianus) after Chemical Immobilization in Clover Traps or Via Ground-darting

Abstract The objective of this prospective observational cohort study in free-ranging female white-tailed deer (Odocoileus virginianus) was to compare the physiologic effects of two methods of anesthetic drug administration: hand-injection in Clover traps and remote injection by dart after ground-stalking. Six trapped and 14 darted female deer were injected with a median (minimum, maximum) of 590 µg/kg butorphanol (401, 1070 µg/kg), plus 235 µg/kg medetomidine (160, 429 µg/kg) intramuscularly. In the trap, the deer struggled when approached and were restrained for injection. Darted deer sprinted away after injection. Once immobilized, deer were transported to a veterinary hospital where blood was collected and vital signs were measured on admission. Admission data from a subset of deer in which measurements were taken within 40 min of trapping (n  =  6) or darting (n  =  5) were analyzed. After salpingectomy under isoflurane and while still anesthetized, another blood sample was collected from all 20 deer. Body weight and immobilization drug doses were not different between groups. On admission, most deer from both groups were hypoxemic, although the darted deer were significantly more hypoxemic. The median rectal temperature in trapped deer was higher than in darted deer, and temperatures higher than 39°C only occurred in trapped deer. The median heart rate in trapped deer was more than twice that in darted deer. Trapped deer had lower median pH and base excess; in trapped deer, the median plasma lactate concentration was more than fivefold higher than in darted deer. After surgery, the median serum creatine kinase concentration was nearly 10-fold higher in trapped deer, and the median cardiac troponin I concentration was higher in trapped deer but undetectable in 10 of 14 darted deer. The white-tailed deer immobilized by hand-injection in Clover traps experienced more severe physiologic perturbations than deer remotely injected by dart after ground-stalking. These perturbations might be sufficient to cause myocardial damage.

Comparison of suburban vaccine distribution strategies to control raccoon rabies.

Helicopters and hand baiting are commonly used to distribute vaccine-laden baits to help control raccoon (Procyon lotor) rabies in suburban landscapes, but these techniques may be labor intensive, costly, or unavailable in some areas. We tested conventional baiting strategies against polyvinyl-chloride (PVC) bait stations in Erie County (New York, USA) during July and August 2003–05. Hand, helicopter, and bait station treatments were randomly assigned to six 25-km2 suburban study sites. To estimate the proportion of raccoons that ingested baits, tooth and blood samples from 954 raccoons were collected and examined for tetracycline biomarker and rabies-neutralizing antibodies, respectively. Overall, 38% (358/954) of the raccoons in Erie County tested positive for tetracycline; 16% (155/954) tested seropositive for rabies virus. Year of study significantly impacted biomarker prevalence; fewer raccoons tested positive for tetracycline in 2004. Probability of seropositivity increased with raccoon age. No statistically significant differences existed between baiting strategies and frequencies of biomarker and antibody-positive raccoons across all years combined. Thus, bait stations could be used as part of an integrated rabies control strategy.

A Polyvinyl Chloride Bait Station for Dispensing Rabies Vaccine to Raccoons in Suburban Landscapes

Abstract Hand-baiting and helicopter distribution are commonly used to distribute vaccine-laden baits to help control raccoon (Procyon lotor) rabies in suburban landscapes. These techniques can be labor intensive and costly. We designed and tested a polyvinyl chloride bait station as an alternative method to dispense the baits to raccoons. Our goal was to build an inexpensive, portable, and weather-resistant bait station that minimized nontarget species visitation. We tested the bait station over a 2-year period. We used infrared-triggered cameras (IRCs) to quantify animal visitation to bait stations. During the study IRCs provided 522 photographs of animals present at bait stations; 90.3% of all animals photographed were raccoons. In 2003 and 2004, approximately 4,651 (93 baits/km2) and 2,960 (59 baits/km2) baits were removed from the bait stations, respectively. We believe the bait stations could potentially replace or supplement hand-baiting and helicopter distribution as a cost-effective method for dispensing rabies vaccine to raccoons in suburban landscapes.

Use of “earn-a-buck” Hunting to Manage Local Deer Overabundance

Abstract Management of overabundant Odocoileus virginianus (White-tailed Deer) populations in suburban and rural landscapes remains controversial, and deer-reduction techniques in these areas are often impeded by public attitudes and safety concerns. Cornell University implemented an “earn-a-buck” (EAB) hunting program to mitigate deer-related impacts on lands surrounding its campus (722 ha) in Ithaca, NY in 2008, and at the University-owned Arnot Teaching and Research Forest (ATRF; 1649 ha) in Cayuta, NY in 1999. The focus of EAB was to increase the harvest of female deer and lower herd size. For the benefit of other entities challenged with White-tailed Deer overabundance, we describe implementation of an EAB hunting program on campus lands. We recorded 257 deer harvested (69–99 each hunting season) on lands near campus. At ATRF, there was an increased harvest of adult does and fawns upon EAB implementation. Moreover, the number of antlered bucks harvested dropped during the first 2 years of EAB when compared to pre-EAB levels. We demonstrated an increased harvest of female deer and improved adult sex ratio during EAB. We monitored program progress via data collected at deer check stations. Deer harvests at ATRF have declined slightly over time, proving beneficial for forest regeneration and biodiversity; however, the question remains how to maintain hunter interest in EAB programs during years of decreased deer numbers.