Abstract European brown hare syndrome (EBHS) is a highly contagious disease caused by a virus in the Lagovirus genus, family Caliciviridae (EBHSV – Lagovirus GII.1). First identified in Italy in 1988, it has since spread and become endemic, affecting various species within the Leporidae family. Notably, it has affected the European hare ( Lepus europaeus ), a common species in North and Central Italy, and the Italian hare ( Lepus corsicanus ), a species of conservation concern endemic to Central and South Italy. This study aimed to determine the presence and to assess the occurrence of EBHS in the province of Grosseto (Tuscany, Central Italy), through a longitudinal survey conducted from 2003 to 2019. We carried out a diagnostic investigation using a competitive enzyme‐linked immunosorbent assay (ELISA) on blood samples from 479 European hares and 58 Italian hares, which had been caught and released to restock hunting areas. We determined the distribution of positive anti‐EBHSV titers stratified by age class, sex, species, years of sampling, and the type of establishment where individuals were caught. The results showed that the disease is apparently more widespread among European hares than among Italian hares. We found a higher prevalence in adults than in young individuals, and no differences between males and females. Most sera had low antibody titers, indicating endemic circulation of EBHSV and a high level of within‐population protection. We used a generalized linear model with a binomial distribution and a logit link function to estimate EBHS prevalence, with 5 fixed effects (sex, age, year of sampling, month of sampling, and zone of hunting). The sex effect was not significant, whereas the age effect influenced the probability of infection, which was higher in adults than in young individuals. The winter months (January, February, and March) had a greater probability of EBHSV infection. No precise trend was revealed regarding the year effect, which might be related to the unbalanced experimental design. The data from this survey, spanning over 15 years, contribute to a better understanding of the dynamics of EBHS in an endemic area and may inform intervention strategies and improve the management of hunting areas.
Abstract Fragmentation caused by roadways can reduce connectivity for terrestrial wildlife species, which can isolate populations and cause reduced gene flow and biodiversity. In the Pigeon River Gorge (PRG) of Tennessee and North Carolina, USA, Interstate 40 separates Great Smoky Mountains National Park from Cherokee and Pisgah national forests, creating a barrier to wildlife movement between largely undeveloped tracts of contiguous forest. Wildlife road mortalities are common on the 51‐km stretch of roadway, with the American black bear ( Ursus americanus ) comprising the greatest proportion of large mammal deaths. Our objective was to use black bear global positioning system (GPS) location data to predict movement and compare road‐crossing behavior of resident and dispersing bears. We used data from conflict bears that were translocated to the PRG as a proxy for dispersers because both would be inexperienced with their new surroundings. We used a combination of hidden Markov models and step selection functions to create a resistance layer for circuit‐theory analysis to predict bear movement (flow) across the landscape. We identified locations along the interstate that had greater‐than‐average flow as key crossing areas. Translocated bears interacted more with the roadway by way of attempted, successful, and unsuccessful crossings, compared with their resident counterparts. Translocated bears had longer step lengths while moving across the landscape. Both translocated and resident bears selected areas with lower percent slope and higher percent canopy, but residents also selected ridgelines and drainages for movement. Flow across the landscape was more generalized for translocated bears, and Interstate 40 was a barrier to movement, particularly for resident bears. Our models predicted several consistent road segments as having greater‐than‐average flow where bears might benefit from crossing structures or other mitigation measures.
Abstract The rehabilitation and release of injured wildlife is a common strategy employed in conservation efforts worldwide. Determining the post‐release survival and factors associated with success in rehabilitation programs is critical in assessing the effectiveness of programs and informing decision‐making throughout the rehabilitation process. To evaluate the success of the black cockatoo conservation program at Murdoch University, we analyzed hospital and rehabilitation records of 118 wild birds across 15 release events between 2015 and 2018 of the 3 threatened black cockatoo species endemic to southwest Western Australia: Carnaby's cockatoo ( Zanda latirostris ), Baudin's cockatoo ( Zanda baudinii ), and the forest red‐tailed black cockatoo ( Calyptorhynchus banksii naso ). We examined variables associated with the demographics, health, rehabilitation, and release of these birds and their associations with post‐release success. Using the results of post‐release tracking studies, we report the observed success rates in birds for which fate was known ( n = 68). Fifty‐four (79.4%) birds met our criterion for post‐release success: survival ≥4 weeks post‐release and reintegration into a wild flock. Given the limited number ( n = 14) of failure events during the study relative to the number of candidate predictors, we examined each variable individually for association with success, rather than fitting a single adjusted model. Larger resident wild flock size at the release site was associated with greater odds of successful release (OR = 5.58, 95% CI = 1.91–22.7, P = 0.005), an association that remained after accounting for clustering of birds released together (mixed‐effects logistic regression: OR = 5.55, P = 0.024). The results from this study highlight the success of this threatened species rehabilitation program and identify resident flock size as a candidate factor warranting further investigation to inform future release‐site selection.
Abstract Population assignment methods enable biodiversity managers to identify the population origins of individuals or samples, which can help to determine the population‐specific impacts of human activities. Although population assignment is a powerful tool, accuracy can be low when populations have unequal odds of being sampled, which may arise from factors such as differences in population sizes, migration patterns, or behavior. When the probability of being assigned to population 1 given the individual is from population 1, , is assumed to be equal to the probability of being from population 1 given that the individual is assigned to population 1 , assignment confidence will be overinflated if the probability of sampling differs between groups. One potential consequence of this overconfidence could be inaccurate delineation of protected areas. To assess the reliability of population assignment, the relevant probability must be used: the probability that an individual belongs to a population given that it was assigned to the population. Understanding and calculating this conditional probability is essential to avoid misinterpretation of results. We demonstrate how to calculate conditional probabilities for assignments, and to identify the conditions under which the ability to assign individuals accurately is poor. We also demonstrate how the probability of correct assignment can be low when dealing with unequally sampled populations. To mitigate these issues, we suggest using population assignment with multiple sources of data and in conjunction with other methods to improve population assignment.
Weather extremes can have dramatic effects on reproduction, survival, and abundance of wildlife populations. Wildlife managers may therefore adjust hunting regulations of game species in an effort to offset consequences of severe weather. In the American Southwest, population dynamics of upland game birds are strongly influenced by interannual variation in precipitation. The reproductive success and survival of Montezuma quail (Cyrtonyx montezumae) in southeast Arizona, USA, are considered to be dependent on summer monsoon precipitation, yet few studies have looked beyond summer rainfall to examine other mechanisms that may be driving Montezuma quail population dynamics and harvest. The objectives of this study were to evaluate and identify underlying drivers of spatiotemporal variation in Montezuma quail harvest, hunter effort, and proportion of harvest consisting of juveniles using voluntary wing data from southeast Arizona collected during 1984-2024. We modeled the effects of weather, remotely sensed vegetation indices, and the previous season's harvest metrics (e.g., proportion of harvest consisting of juveniles) on Montezuma quail hunter harvest and effort. Quail harvest had a strong positive association with monsoon precipitation and the proportion of juveniles in the previous year's harvest. Hunters also expended greater effort during years with greater monsoon precipitation. Hunter harvest and effort generally increased over time, whereas the proportion of harvest consisting of juveniles decreased over time. Harvest and hunter effort were not lower during years when daily bag limit was 8 relative to 10 or 15. While resident and non-resident hunters had similar harvest rates, non-resident hunter effort strongly increased during our study, resulting in greater total harvest by non-residents by the end of our study. Our results indicate that environmental conditions and changes in hunter composition and behavior are the primary drivers underlying spatiotemporal variation in Montezuma quail harvest.
