Sylvatic plague, caused by Yersinia pestis, frequently afflicts prairie dogs (Cynomys spp.), causing population declines and local extirpations. We tested the effectiveness of bait-delivered sylvatic plague vaccine (SPV) in prairie dog colonies on 29 paired placebo and treatment plots (1–59 ha in size; average 16.9 ha) in 7 western states from 2013 to 2015. We compared relative abundance (using catch per unit effort (CPUE) as an index) and apparent survival of prairie dogs on 26 of the 29 paired plots, 12 with confirmed or suspected plague (Y. pestis positive carcasses or fleas). Even though plague mortality occurred in prairie dogs on vaccine plots, SPV treatment had an overall positive effect on CPUE in all three years, regardless of plague status. Odds of capturing a unique animal were 1.10 (95% confidence interval [C.I.] 1.02–1.19) times higher per trap day on vaccine-treated plots than placebo plots in 2013, 1.47 (95% C.I. 1.41–1.52) times higher in 2014 and 1.19 (95% C.I. 1.13–1.25) times higher in 2015. On pairs where plague occurred, odds of apparent survival were 1.76 (95% Bayesian credible interval [B.C.I.] 1.28–2.43) times higher on vaccine plots than placebo plots for adults and 2.41 (95% B.C.I. 1.72–3.38) times higher for juveniles. Our results provide evidence that consumption of vaccine-laden baits can protect prairie dogs against plague; however, further evaluation and refinement are needed to optimize SPV use as a management tool.Electronic supplementary materialThe online version of this article (doi:10.1007/s10393-017-1253-x) contains supplementary material, which is available to authorized users.

Road mortality of freshwater turtles can be high enough to imperil populations near roads, thus there is a need to efficiently and accurately locate regions of excessive roadkill along road networks for mitigation. Weekly over 2 years, we drove a 160 km highway circuit in northeastern New York State, USA and recorded the location of all detected roadkill of three freshwater turtle species (Chelydra serpentina, Chrysemys picta, Emydoidea blandingii). We then analyzed the spatial dispersion of road-kill and the road and landscape features associated with road-kill locations. Road-kill was most prevalent at a limited number of short road segments, termed 'hotspots'. The locations of hotspots, as indicated by kernel density analysis, and the peak spatial extent of hotspots (250 m), as indicated by Ripley's K, corresponded to the locations and average lengths of causeways (road segments with wetlands within 100 m on both sides). Hotspots were located at causeways that were greater than 200 m length and characterized by high traffic volumes, close proximity to water, and high forest coverage. We conclude that freshwater turtle road mortality is spatially aggregated at short, severe hotspots, and hotspot locations can be predicted when the locations of wetlands, traffic volumes, and the land-uses bordering roads are known. Hotspot models using these predictors can locate sites along a road network that are the most promising for mitigation to reduce excessive road mortality and maintain connectivity.

The plague bacterium Yersinia pestis is lethal to endangered black-footed ferrets ( Mustela nigripes , BFF) and the prairie dogs ( Cynomys spp., PD) on which they depend for habitat and prey. We assessed the effectiveness of an oral sylvatic plague vaccine delivered in baits to black-tailed PD ( Cynomys ludovicianus , BTPD) from 2013 to 2017 on the Charles M. Russell National Wildlife Refuge (CMR) in northcentral Montana. We permanently marked BTPD on four paired vaccine ( N = 1,349 individuals) and placebo plots ( N = 926; 7,027 total captures). We analyzed capture–recapture data under a Cormack–Jolly–Seber model to estimate annual apparent survival. Overall, survival averaged 0.05 lower on vaccine plots than on paired placebo plots. Immediately before noticeable die-offs and detecting plague on pairs CMR1 and CMR2, 89% of BTPD sampled on vaccine plots had consumed at least one bait and the immune systems of 40% were likely boosted by consuming baits over multiple years. Survival to the following year was 0.16 and 0.05 on the vaccine plots and 0.19 and 0.06 on the placebo plots for pairs CMR1 and CMR2, respectively. These rates were markedly lower than 0.63, the overall average estimate on those same plots during the previous 3 years. PD populations subjected to such large die-offs would not be expected to sustain a BFF population. An overriding limitation to achieving sufficient protection rests with vaccine delivery constraints. Late summer/fall bait distribution results in the highest bait uptake rates. However, the PD birth pulse each spring can double the size of populations in most years, greatly reducing the proportion of vaccinates in populations and diminishing potential herd immunity benefits. In addition to nonvaccinated juveniles and PD that do not consume bait, incomplete vaccine protection and time required for immunity to develop leaves a large majority of PD populations vulnerable to plague for 6–7 months or more each year.

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The northern flying squirrel (Glaucomys sabrinus) is currently recognized as a keystone species because of a symbiotic relationship between the squirrel, mycorrhizal fungi, and mature forests. As habitat loss threatens to challenge populations of flying squirrels range-wide, wildlife managers and conservationists could benefit from new techniques to survey this nocturnal and secretive species. Here, we developed a novel noninvasive survey technique that combined remote cameras with enclosed bait tubes designed specifically for detecting the presence of flying squirrels. We used this technique to survey for northern flying squirrels throughout their range in Wyoming, USA, from May to October 2012-2014. This technique produce average daily probability detection rates of 54% (SE ¼ 0.02%) with greater rates in the autumn (Aug-Oct). Detection rates varied with length of survey and number of camera stations, providing flexibility for managers to modify survey design depending on project objectives. This technique also nullified the risk of capture myopathy, to which flying squirrels may be susceptible when surveyed using live-trapping methods. Our results suggest that remote cameras combined with enclosed bait tubes can be a cost-efficient and effective tool in assessing and monitoring population trends in occupancy and distribution of northern flying squirrels throughout their range. Ó 2016 The Wildlife Society.