Kurt C. VerCauteren

Effects of agricultural activities and hunting on home ranges of female white-tailed deer

Insight into the effects of agricultural activities and hunting on deer could be used to facilitate management. We examined home range characteristics of female white-tailed deer (Odocoileus virginianus) relative to corn development, corn harvest, and hunting seasons from 1991 to 1993. Among 30 radiomarked does, 53% (n = 16) remained residents of DeSoto National Wildlife Refuge (DNWR) throughout the study; 47% (n = 14) were transients. Among the transients, 30% (n = 9) permanently emigrated from DNWR and 17% (n = 5) migrated annually. Dispersal occured in April and May. Annual home ranges of resident does averaged 170 ha (CI = 38, n = 14). Home range centers shifted an average of 174 m (CI = 74, n = 14) closer to cornfields when corn was in the tasseling-silking stage of development. After corn harvest, home range centers shifted 157 m (CI = 63, n = 12) away from crop fields and into areas of permanent cover. Home range sizes increased 32% (9-64% CI) after corn harvest because does were forced to find and use other sources of cover and food. Resident does that caused local crop damage during the growing season were available for hunter harvest in the same areas where they caused damage. Migrators appeared especially vulnerable because they were exposed to state firearm and archery seasons and the DNWR 3-day muzzleloader hunt. Of all tagged deer, 20% of transients (3 of 15) were harvested legally, whereas 40% of residents (8 of 20) were harvested. Harvest or removal to reduce crop damage around large areas of permanent cover should be conducted in early to mid-fall, which can reduce deer densities in the immediate area but not impose additional hunting pressure on migratory deer.

Fences and Deer-Damage Management: A Review of Designs and Efficacy

Abstract White-tailed deer (Odocoileus virginianus) may cause more damage than any other species of wildlife. These damages include crop loss, automobile and aviation collisions, disease transmission, environmental degradation, and destruction of ornamental plantings. One practical method of controlling deer damage is the use of exclusionary fences. The relatively high cost of labor and materials required to build effective fences has limited most applications to the protection of orchards, vegetable farms, other high-value resources, and mitigation of human health and safety risks. Improvements in fence technology resulting in less expensive, yet effective fences have expanded the use of fences to manage damage caused by deer. Fences typically installed to manage white-tailed deer damage include wire or plastic mesh, electrified high-tensile steel wire, and electrified polytape or polyrope fence. We reviewed the scientific literature on fencing to determine which fence designs would be the most effective for excluding deer in a variety of situations.

FERAL SWINE CONTACT WITH DOMESTIC SWINE: A SEROLOGIC SURVEY AND ASSESSMENT OF POTENTIAL FOR DISEASE TRANSMISSION

Feral swine (Sus scrofa) are present in 38 of the 50 United States, and their populations continue to expand. Domestic swine are widely regarded as vulnerable to diseases harbored by feral swine. Our objectives were to determine antibody prevalence for selected pathogens in Texas feral swine populations and identify contact events between feral and domestic swine. Overall prevalence of antibodies against brucellosis and pseudorabies virus was 11% and 30%, respectively. Antibodies to porcine reproductive and respiratory disease virus were detected in 3% of feral swine from southern Texas. All samples tested negative for antibodies to classical swine fever virus. To determine the frequency of contact events between feral swine and domestic swine in neighboring facilities, we analyzed movement data from 37 adult feral swine that were trapped ≤10 km from domestic swine facilities and equipped with geographic positioning system collars. Seven of the 37 feral swine had contact (relocated within 100 m) with domestic swine. We found that contact between feral swine and domestic swine occurred predominantly at night. Additionally, we analyzed 60 consecutive days of experimental track plots around pens that contained domestic swine and empty control pens, and found greater visitation by feral swine to the domestic swine pens. Our data demonstrate that feral swine have direct contact with domestic swine, which presents opportunity for disease transmission.

Livestock Protection Dogs in the 21st Century: Is an Ancient Tool Relevant to Modern Conservation Challenges?

Europe and North America share a similar history in the extirpation and subsequent recovery of large carnivore and ungulate species. Both continents face challenges and opportunities for managing human-wildlife conflict at the junction of livestock production and wildlife conservation. Predation of livestock and disease transmission between wildlife and livestock is an ongoing and escalating worldwide issue. In order to manage this conflict, producers need effective tools, and they have used livestock protection dogs (LPDs) for reducing predation for well over 2000 years. We review the history of the use of LPDs, including the loss of information on their use and the paucity of scientific research on their effectiveness. We discuss the potential for LPDs to be integral components in modern-day livestock husbandry and outline future directions to pursue.

Detection of PrP(CWD) in postmortem rectal lymphoid tissues in Rocky Mountain elk (Cervus elaphus nelsoni) infected with chronic wasting disease.

Preclinical diagnostic tests for transmissible spongiform encephalopathies have been described for mule deer (Odocoileus hemionus), using biopsy tissues of palatine tonsil, and for sheep, using lymphoid tissues from palatine tonsil, third eyelid, and rectal mucosa. The utility of examining the rectal mucosal lymphoid tissues to detect chronic wasting disease (CWD) was investigated in Rocky Mountain elk (Cervus elaphus nelsoni), a species for which there is not a live-animal diagnostic test. Postmortem rectal mucosal sections were examined from 308 elk from two privately owned herds that were depopulated. The results of the postmortem rectal mucosal sections were compared to immunohistochemical staining of the brainstem, retropharyngeal lymph nodes, and palatine tonsil. Seven elk were found positive using the brainstem (dorsal motor nucleus of the vagus nerve), retropharyngeal lymph nodes, and palatine tonsil. Six of these elk were also found positive using postmortem rectal mucosal sections. The remaining 301 elk in which CWD-associated abnormal isoform of the prion protein (PrPCWD) was not detected in the brainstem and cranial lymphoid tissues were also found to be free of PrPCWD when postmortem rectal mucosal sections were examined. The use of rectal mucosal lymphoid tissues may be suitable for a live-animal diagnostic test as part of an integrated management strategy to limit CWD in elk.

Livestock Protection Dogs for Deterring Deer From Cattle and Feed

Abstract Disease transmission between wildlife and livestock is a worldwide issue. Society needs better methods to prevent interspecies transmission to reduce disease risks. Producers have successfully used livestock protection dogs (LPDs) for thousands of years to reduce predation. We theorized that LPDs raised and bonded with cattle could be used to also reduce risk of bovine tuberculosis (Myobacterium bovis; TB) transmission between white-tailed deer (Odocoileus virginianus) and cattle by minimizing contact between the 2 species and use of cattle feed by deer. We evaluated 4 LPDs over 5 months, utilizing 2 data collection methods (direct observation and motion-activated video) on deer farms that supported higher densities than wild populations. Dogs were highly effective in preventing deer from using concentrated cattle feed (hay bales), likely the greatest risk factor of TB transmission on farms. Dogs also prevented deer from approaching cattle in core areas of pastures (near hay bales) and were very effective throughout pastures. Our research supports the theory that LPDs, specifically trained to remain with cattle, may be a practical tool to minimize potential for livestock to contract TB from infected deer in small-scale cattle operations. Where disease is present in deer, it may be possible to reduce the potential for disease transmission by employing LPDs.

Antemortem detection of PrPCWD in preclinical, ranch-raised Rocky Mountain elk (Cervus elaphus nelsoni) by biopsy of the rectal mucosa.

Antemortem biopsy of the rectal mucosa was evaluated as a method for the preclinical diagnosis of chronic wasting disease (CWD) in a herd of ranch-raised Rocky Mountain elk (Cervus elaphus nelsoni) quarantined because of exposure to CWD. Biopsy samples were obtained from 41 elk during the winter of 2005–2006 and from 26 elk from that herd still alive and available for testing during the winter of 2006–2007. Samples were examined for PrPCWD, the protein marker for CWD infection, by immunohistochemistry. PrPCWD was detected in follicles of the rectoanal mucosa–associated lymphoid tissue in biopsy samples from 1 elk with clinical signs of chronic wasting disease and 5 clinically normal elk. The diagnosis was confirmed in all 6 animals by postmortem analysis of brain and peripheral lymph nodes. PrPCWD was also observed in the submucosal plexus and myenteric plexus of the enteric nervous system, and in close association with nonmyelinated mucosal and submucosal nerve fibers. In antemortem rectal biopsy samples from positive animals, immunostaining was consistently observed in approximately 60% of the mucosa-associated lymphoid tissue follicles if 10 or more total follicles per biopsy were present for evaluation. Most antemortem biopsy samples obtained from elk younger than 6.5 years contained at least 10 follicles per rectal mucosal biopsy. These findings support the analysis of antemortem biopsy of the rectal mucosa samples as part of an integrated strategy to manage chronic wasting disease in Rocky Mountain elk.

Sentinel-based Surveillance of Coyotes to Detect Bovine Tuberculosis, Michigan

Coyotes could be used as sentinels to detect Mycobacterium bovis in the wild.

What Is the Proper Method to Delineate Home Range of an Animal Using Today’s Advanced GPS Telemetry Systems: The Initial Step

The formal concept of an animal’s home range, or derivations thereof, has been around for over half a century (Burt 1943). Within this time frame there have been countless published studies reporting home range estimators with no consensus for any single technique (Withey et al., 2001; Laver & Kelly 2008). Recent advances in global positioning system (GPS) technology for monitoring home range and movements of wildlife have resulted in locations that are numerous, more precise than very high frequency (VHF) systems, and often are autocorrelated in space and time. Along with these advances, researchers are challenged with understanding the proper methods to assess size of home range or migratory movements of various species. The most acceptable method of home-range analysis with uncorrelated locations, kernel-density estimation (KDE), has been lauded by some for use with GPS technology (Kie et al., 2010) while criticized by others for errors in proper bandwidth selection (Hemson et al., 2005) and violation of independence assumptions (Swihart & Slade 1985b). The issue of autocorrelation or independence in location data has been dissected repeatedly by users of KDE for decades (Swihart & Slade 1985a; Worton 1995, but see Fieberg 2007) and can be especially problematic with data collected with GPS technology. Recently, alternative methods were developed to address the issues with bandwidth selection for KDE and autocorrelated GPS data. Brownian bridge movement models (BBMM), which incorporate time between successive locations into the utilization distribution estimation, were recommended for use with serially correlated locations collected with GPS technology (Bullard 1999; Horne et al., 2007). The wrapped Cauchy distribution KDE was also introduced to incorporate a temporal dimension into the KDE (Keating & Cherry 2009). Improvements were developed in bandwidth selection for KDE

Spatial Ecology of Raccoons Related to Cattle and Bovine Tuberculosis in Northeastern Michigan

Abstract In 1995, Mycobacterium bovis, the causative bacterium of bovine tuberculosis (bTB), was detected in 5 beef cattle operations in Alcona County, Michigan, USA. In accordance with Federal law, the operations were depopulated to prevent the spread of bTB. Subsequent wildlife surveillance programs identified high prevalence of M. bovis in mesocarnivores, including raccoons (Procyon lotor), which suggested that raccoons may be complicit in vectoring the pathogen among livestock operations. Our goal was to develop an empirical basis for generating hypotheses about the likelihood for raccoons to mediate the transmission of bTB to livestock. We found intersexual differences in scale-dependent resource selection and probability of spatial interaction that, under certain circumstances, may form the foundation for a sex-bias in disease transmission. Spatial dispersion of mixed-forest patches facilitated overlap of adjacent males, whereas female overlap zones included pastures. Within overlap zones, probabilities of interaction for male–male and male–female dyads were greater than for female–female dyads, although we documented an elevated likelihood of spatial interaction between raccoons and livestock around cattle-feeding troughs and water sources, regardless of sex. Partial regressions generated by linear models indicated that distance between nearest-neighbor mixed-forest patches explained most of this observed variation. These results supported our prediction that forest patches juxtaposed with anthropogenic features fostered social tolerance between males and, thus, facilitated spatial interaction and exploitation of anthropogenic features. In raccoons, sex and landscape composition influenced pathogen transmission potential. We suggest that livestock producers locate livestock feeding and watering features away from forest patches to mitigate future outbreaks of bTB in endemic areas.