Recent evidence from across the southeastern United States indicating high predation rates by coyotes (Canis latrans) on white‐tailed deer (Odocoileus virginianus) fawns has led some managers to implement coyote control. Although some evidence suggests coyote control can improve recruitment, success appears to be site dependent. Therefore, we designed an experiment to assess feasibility of coyote control as a management action to increase recruitment on B.F. Grant and Cedar Creek Wildlife Management Areas (WMA) in central Georgia, USA. We estimated annual coyote abundance during 2010–2012 using a noninvasive mark–recapture design and fawn recruitment using infrared‐triggered camera surveys. During March–June 2011 and March–April 2012, trappers removed coyotes from both sites. Estimates of coyote abundance on B.F. Grant WMA after trapping were 81% (2011) and 24% (2012) lower than during preremoval. Coyote abundance estimates were similar among years on Cedar Creek WMA. Fawn recruitment on B.F. Grant WMA averaged 0.65 fawns/adult female prior to removal and 1.01 fawns/adult female during the 2 years following the removals. Fawn recruitment on Cedar Creek WMA did not differ among years during the study, and was similar to that prior to coyote arrival. The differential coyote impacts and variable effectiveness of trapping we observed on nearby sites suggest coyote control may not achieve management objectives in some areas. Furthermore, transient behavior and the potential for coyotes to adapt to control efforts likely reduce efficacy of this management action. However, we observed an increase in recruitment on B.F. Grant WMA during one year, and others have seen similar responses. Therefore if lowered fawn recruitment is hindering achievement of management objectives, we recommend managers who opt to control coyotes continuously monitor recruitment to determine whether a response occurs. © 2015 The Wildlife Society.

Cranial/intracranial abscess disease is an emerging source of significant mortality for male white-tailed deer (Odocoileus virginianus). Most cases of cranial/intracranial abscess disease are associated with infection by the opportunistic pathogen Trueperella pyogenes although the relationship between the prevalence of the bacteria and occurrence of disease is speculative. We examined 5,612 hunter-harvested deer from 29 sites across all physiographic provinces in Georgia for evidence of cranial abscess disease and sampled the forehead, lingual, and nasal surfaces from 692 deer. We used polymerase chain reaction (PCR) to determine presence of T. pyogenes from these samples. We found T. pyogenes prevalence at a site was a predictor for the occurrence of cranial abscess disease. Prevalence of T. pyogenes did not differ between samples from the nose or tongue although prevalence along the forehead was greater for males than females (p = 0.04), particularly at sites with high occurrence of this disease. Socio-sexual behaviors, bacterial prevalence, or physiological characteristics may predispose male deer to intracranial/cranial abscess disease. Determination of factors that affect T. pyogenes prevalence among sites may help explain the occurrence of this disease among populations.

ABSTRACT:Intracranial abscess disease is a cause of natural mortality for mature male whitetailed deer (Odocoileus virginianus). Most cases of abscesses are associated with bacterial infection by Trueperella (Arcanobacterium) pyogenes, but a complete understanding of the epidemiology of this disease is lacking. We quantified the effects of individual characteristics, site-specific herd demographics, land cover, and soil variables in estimating the probability of this disease. We examined 7,545 white-tailed deer from 60 sites throughout Georgia, US for signs of cranial abscesses, the predecessor of intracranial abscesses, and recorded the presence or absence of cranial abscesses for each individual examined. We detected no cranial abscesses in 2,562 female deer but 91 abscesses in 4,983 male deer examined (1.8%). A generalized linear mixed model, treating site as a random effect, was used to examine several potential explanatory risk factors including site-level landscape and soil characteristics (soil and forest type), demographic factors (deer density and male to female ratio), and individual host factors (deer sex and age). Model results indicated that the probability of a male having a cranial abscess increased with age and that adult sex ratio (male:female) was positively associated with this disease. Site-specific variables for land cover and soil types were not strongly associated with observations of the disease at the scale measured and a large amount of among-site variability remained. Given the demonstrated effect of age, gender, and local sex ratios but the remaining unexplained spatial variability, additional investigation into spatiotemporal variation of the presumed bacterial causative agent of cranial abscesses appears warranted.

Questions concerning the effects on other wildlife species by coyotes (Canis latrans) in recently colonized areas, including the southeastern United States, continue to receive attention in the literature. Coyote abundance estimates, achieved via genetic sampling of feces, can be useful in answering such questions. However, rapid degradation of fecal DNA in humid subtropical climates, like that of the southeastern United States, may limit the efficacy of the technique. To evaluate this hypothesis, we collected and analyzed 434 suspected coyote scats from February 2010 to April 2012 on 2 sites in central Georgia, USA. We quantified seasonal and comprehensive genotyping success, and the effect of sampling effort on precision of closed population abundance estimates. We successfully species-typed 316 (73%) scats, 219 (69%) of which belonged to coyotes. Of those, 136 (62%) yielded multilocus genotypes. The seasonal probability of genotyping a scat ranged from 0.53 to 0.71. Scats collected during spring were more likely to yield consensus genotypes, but the overall effect of season on genotyping success was minimal. The median CV for model-averaged b N (i.e., coyote abundance) using the complete data set was relatively precise (<15%). Precision of abundance estimates decreased with decreasing sampling effort, but CV values remained <20% with up to a 25% reduction in effort. Our findings related to genotyping success demonstrate noninvasive genetic sampling of feces is a promising technique for estimating coyote abundance in humid subtropical climates. Combined with our results regarding sampling effort, these findings can aid in designing surveys capable of achieving desired objectives in similar environments. Ó

Antler‐based selective harvest criteria (SHC; e.g., number of points) are a commonly used and effective method of limiting harvest of 1.5‐year‐old male white‐tailed deer (Odocoileus virginianus). However, previous research has shown SHC that allow disproportionate harvest of young males with large antlers may reduce average antler size within older (≥2.5‐yr) age classes. We used hunter‐harvest data collected from 10 wildlife management areas in Georgia, USA, during 2003–2013 to compare cohort antler size and other factors among areas with varying or no SHC. Three of the areas restricted harvest to males with one antler beam ≥41 cm long or an antler spread ≥38 cm (BS), and another 3 restricted harvest to males with ≥4 antler points on one side (4OS). Any male with visible antlers was eligible for harvest on the remaining areas. There was no evidence that either BS or 4OS criteria led to a decrease in antler size of harvested males ≥2.5 years old. Both SHC protected ≥96% of 1.5‐year males from harvest. There was also evidence to suggest the BS criteria increased mean antler size of harvested males and annual harvest rates of 3.5‐year males. However, the 4OS criteria protected 49%, 16%, and 9% of 2.5, 3.5, and ≥4.5‐year males, respectively. The BS criteria protected 77%, 33%, and 10% of the same age classes. These findings suggest restrictive SHC can prevent decline in antler size of harvested males and increase opportunity for hunters to harvest older males with larger antlers, with the added biological benefit of increasing the population age structure. However, restrictive SHC may unintentionally protect a significant proportion of ≥2.5‐year males from harvest. As previously suggested, managers interested in SHC should carefully research site‐ and age‐specific antler size to avoid implementation of criteria that are either too restrictive or permissive. © 2019 The Wildlife Society