Scholarly Works, Fish and Wildlife Conservation

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Demographic feedbacks during evolutionary rescue can slow or speed adaptive evolution
Draghi, Jeremy A.; McGlothlin, Joel W.; Kindsvater, Holly K. (The Royal Society, 2024-02-14)
Populations declining toward extinction can persist via genetic adaptation in a process called evolutionary rescue. Predicting evolutionary rescue has applications ranging from conservation biology to medicine, but requires understanding and integrating the multiple effects of a stressful environmental change on population processes. Here we derive a simple expression for how generation time, a key determinant of the rate of evolution, varies with population size during evolutionary rescue. Change in generation time is quantitatively predicted by comparing how intraspecific competition and the source of maladaptation each affect the rates of births and deaths in the population. Depending on the difference between two parameters quantifying these effects, the model predicts that populations may experience substantial changes in their rate of adaptation in both positive and negative directions, or adapt consistently despite severe stress. These predictions were then tested by comparison to the results of individual-based simulations of evolutionary rescue, which validated that the tolerable rate of environmental change varied considerably as described by analytical results. We discuss how these results inform efforts to understand wildlife disease and adaptation to climate change, evolution in managed populations and treatment resistance in pathogens.
Characterization of Diarrheagenic Escherichia coli and Salmonella enterica from Produce in the Chobe District of Botswana
Bywater, Auja; Dintwe, Galaletsang; Alexander, Kathleen A.; Ponder, Monica A. (Elsevier, 2024-08-24)
Diarrheal disease is a leading cause of death in children in low- and moderate-income countries. Fresh produce, including fruits and vegetables, may harbor diarrheal disease-causing bacteria including strains of Salmonella enterica and Escherichia coli. This study aimed to determine the prevalence and antibiotic resistance profiles of S. enterica and E. coli isolated from produce samples (n = 207) obtained from retail markets in northern Botswana in Chobe District of Botswana in 2022. Samples were enriched in the appropriate selective media: Brilliant Green Bile Broth for E. coli and Rappaport Vassiliadis Broth for S. enterica. E. coli were confirmed by PCR detecting the phoA gene, and classified as potentially pathogenic through screening for the eae, stx, and stx2 and estIb genes. S. enterica isolates were confirmed using invA primers. Isolates were evaluated for resistance to ampicillin, amoxicillin-clavulanic acid, chloramphenicol, cefotaxime, doxycycline, streptomycin, sulfamethoxazole, and tetracycline antibiotic using the Kirby-Bauer Disk Diffusion method. E. coli was isolated from 15.5% of produce samples (n = 207). The gene eae was detected from 1.5% of samples, while stx1, stx2, and estIb were not detected. Resistance to one or more antibiotics was common (72%) with the majority of the resistant E. coli (n = 32) isolated from fruits (22%) and greens (18%) compared to other types of vegetables. Multidrug resistance (MDR, resistant to 3 or more antibiotics) was identified in 18% of samples. S. enterica was isolated from 3.4% of produce samples (7, n = 207). Resistance was uncommon among the S. enterica isolates (1/7). Overall prevalence of diarrheagenic S. enterica and E. coli was low; however, their presence and that of MDR E. coli in foods commonly consumed raw increases the risk to vulnerable populations. Strategies to reduce contamination of fresh produce and public education on washing and cooking some types of produce may be useful to reduce disease.
Antibiotic Resistance Profiles of Escherichia coli isolated from Chobe River water in the Northern Botswana
Fleming, Madison; Yi, Saehah; Ponder, Monica A.; Patino, Lena; Alexander, Kathleen A. (2024-04-26)
Antibiotic Resistance Profiles of Escherichia coli Isolated from Elephants in the Chobe Region of Botswana
Haddadin, Maisoon; Patino, Lena; Ponder, Monica A.; Alexander, Kathleen A. (2024-04-26)
Characterization of Escherichia coli isolated from poultry in the Chobe region of Botswana by molecular methods
Yi, Saehah; Bywater, Auja; Dintwe, Galaletsang; Haidl, Thomas; Cameron, Andrew; Ponder, Monica A.; Alexander, Kathleen A. (2024-07-15)
Introduction: Diarrheal illness incidence is high in rural dryland environments, including the Chobe region of Botswana, where peaks are often associated with high rainfall events. Antibiotic resistance (ABR) is also a growing problem in the region. Contributions of poultry to diarrheal illness and ABR in the region are not well understood. Purpose: Characterize the virulence potential and ABR of E.coli isolated from chicken purchased from local vendors in Botswana using molecular techniques, including whole genome sequencing. Methods: Poultry was purchased in Kasane, Botswana and enriched within 24h. E.coli was isolated using MacConkey and EMB agar. Isolates were shipped to Virginia Tech for molecular and antibiotic resistance characterization. Multiplex PCR was used to detect presence of genes phoA (all E.coli), and diarrheagenic E.coli (eae, and est1b). Phenotypic ABR was determined using CLSI disk diffusion methods. Whole genome sequencing was performed using an Illumina MiSeq system and genome annotated using BV-BRC. Results: E.coli was isolated from 62% (38/61) of poultry samples. Five isolates were classified as diarrheagenic based on eae, none were positive for est1LB. Multidrug resistance (3+) was seen in 26 isolates and resistance to 1 or more antibiotics in 41 E.coli isolates. Resistance amongst chicken isolates was as follows: tetracycline (29), doxycycline (21), sulfamethoxazole (20), streptomycin (15), ampicillin (15), chloramphenicol (9), ciprofloxacin (6), gentamicin (4), c ceftriaxone (4), amoxicillin-clavulanic acid (3) and azithromycin (1). Comprehensive analysis of the genomes from chicken intestinal isolates revealed large numbers of virulence genes (125-252) common amongst diarrheagenic E.coli. Antibiotic resistance genes (65-85) were also present including those encoding resistance to ampicillin, ceftriaxone, doxycycline, streptomycin, and tetracycline. Significance: While prevalence of diarrheagenic E.coli was low, antibiotic resistant E.coli were frequently isolated. E.coli may be an important sentinel species to evaluate ABR emergence and effectiveness of control strategies by Botswana poultry producers.
Environmental complexity impacts anxiety in broiler chickens depending on genetic strain and body weight
Ulans, Alexandra; Brooks, George C.; Jacobs, Leonie (Nature Portfolio, 2024-07-30)
The objective was to assess the impact of environmental complexity on affective state (anxiety) in fast- and slow-growing broilers (Gallus gallus domesticus) as they gain weight. Six hundred fast-growing broilers (Ross 708; “fast-growers”) and 600 slow-growing broilers (Hubbard Redbro Mini; “slow-growers”) were raised in 24 pens with simple (standard; SE) or complex (permanent and temporary enrichments; CE) environments. Six birds/pen underwent the attention bias test on day 23 (fast-growers only), 28–29, 35–36, 42–43, and 56–57 (slow-growers only), with individuals only tested once (n = 576). Proportion of birds feeding, time spent vigilant and latencies to eat and step were recorded. Greater vigilance and longer latencies indicate more anxiety. Slow-growers fed more (p = 0.001), were less vigilant (p = 0.003), and stepped sooner than fast-growers (p = 0.007). For both strains, likelihood of feeding was unrelated to weight in SE, but decreased with increasing weight in CE (p = 0.048). Birds in CE stepped sooner than birds in SE (p = 0.030). Vigilance increased with body weight (p = 0.024). These results indicate that affective state (anxiety) can change as birds gain weight, depending on environmental complexity and genetic strain. Overall, slow-growers showed reduced anxiety compared to fast-growers, across housing treatments or weights.
First satellite track of a juvenile shortfin mako shark (Isurus oxyrinchus) in the Mediterranean Sea
Shea, Brendan D.; Chapple, Taylor K.; Echwikhi, Khaled; Gambardella, Chiara; Jenrette, Jeremy F.; Moro, Stefano; Schallert, Robert J.; Block, Barbara A.; Ferretti, Francesco (Frontiers, 2024-12-09)
The shortfin mako shark (Isurus oxyrinchus) is a highly mobile, coastal littoral, and epipelagic oceanic species broadly distributed in tropical, subtropical, and temperate seas worldwide (Rigby et al., 2019). In recent years, there has been growing recognition of the impacts of overfishing on shortfin mako populations, and the species is now listed as Endangered by the International Union for the Conservation of Nature (IUCN) (Rigby et al., 2019). The species is listed as Critically Endangered in the Mediterranean Sea due to long-term and continuing exploitation coupled with inadequate management (Walls and Soldo, 2016). Of particular concern is the ongoing capture of juvenile mako sharks in the Central Mediterranean and the Strait of Sicily, which have been identified as potential nursery areas (Walls and Soldo, 2016; Cattano et al., 2023; Mancusi et al., 2023). Even with significant declines in pelagic sharks regionally (Ferretti et al., 2008), sharks continue to be occasionally targeted in the Mediterranean Sea, though the most critical risk to shark populations in the region is bycatch in other fisheries (Bradai et al., 2018; Carpentieri et al., 2021). In the Mediterranean, most fishers typically retain their shark bycatch, with some estimates of shark discard rates as low as 1% (Megalofonou et al., 2005) even for protected species, though discard rates are likely to vary by season and gear (Carpentieri et al., 2021). Despite their imperiled status, shortfin mako sharks remain one of the region’s commonly encountered sharks for fishers, especially for longlines (Carpentieri et al., 2021), and sharks are typically retained despite falling under regional protections such as the Bern Convention, Bonn Convention, and Barcelona Convention (Serena et al., 2014). Of additional concern is the relatively unmonitored recreational fishery, which may additionally encounter high numbers of shortfin mako sharks, many of Frontiers in which are retained, but the scale of this fishery is not well known (Udovičić et al., 2019; Panayiotou et al., 2020). Concerningly, young-of-the-year (YOY) and juvenile specimens comprise the bulk of captured individuals reported in the Mediterranean (Saidi et al., 2019; Udovičić et al., 2019; Panayiotou et al., 2020; Cattano et al., 2023; Mancusi et al., 2023; Scacco et al., 2023). Given the life history of shortfin mako sharks, particularly their advanced age at maturity (Natanson et al., 2020), this frequent and ongoing capture of juvenile sharks represents a severe threat to regional populations, as many sharks will never reach maturity, let alone successfully reproduce. These losses highlight the need for more detailed information regarding the movement patterns and space use of juvenile shortfin mako sharks, for which little is known in the Mediterranean. In recent years, a proliferation of telemetry studies has drastically improved our understanding of themovements and space use of large marine predators like shortfin mako sharks around the globe (Queiroz et al., 2019); however, virtually no study has focused on Mediterranean populations, especially sharks. Here, we report the satellite track from a pop-off archival tag (PAT) deployed on a juvenile shortfin mako shark in the Mediterranean Sea in May 2023. To our knowledge, this track represents the first satellite tag deployed on a shortfin mako shark in the Mediterranean Sea. We describe the horizontal and vertical movements the study shark performed over 54 days at liberty (DAL), discussing potential drivers for the observed movements and the implications of the track for the conservation of shortfin mako sharks regionally.
Social support and identity promote diverse participation in wildlife viewing
Jennings, Kelsey K.; Dayer, Ashley A.; Chaves, Willandia A. (Wiley, 2024-08-07)
1. Wildlife viewing is growing in popularity, especially among Black, Indigenous and people of colour (BIPOC), whose participation has increased dramatically in the last 20 years. We used a nationwide sample of wildlife viewers to examine how identity as a wildlife viewer, the importance of wildlife viewing to one's life, ethnoracial identity and social support influenced the degree of participation in wildlife viewing. 2. We examined data as part of a non-probabilistic online survey of wildlife viewers (n = 17,104). We were particularly interested in how participation, support, the importance of wildlife viewing, and identity as wildlife viewers varied across ethnoracial groups. Support has been found to influence involvement in various activities, while identity and importance have been shown to drive continued participation, suggesting that these factors may be of great value for encouraging and sustaining behaviour. 3. We found that, compared with White groups, multiple ethnoracial groups identified less as wildlife viewers. However, they indicated that wildlife viewing is more important to their lives. We also found that most ethnoracial groups received more support from friends, family, mentors and peers than White viewers. 4. This research can help understand the participation of Black, Indigenous and people of colour in outdoor recreation. Furthermore, this work demonstrates how legacies of racially motivated discriminatory policies may limit participation among ethnoracially diverse communities.
Gape-limited invasive predator frequently kills avian prey that are too large to swallow
Kastner, Martin; Goetz, Scott M.; Baker, Kayla M.; Siers, Shane R.; Paxton, Eben H.; Nafus, Melia G.; Rogers, Haldre S. (Wiley, 2024-07-25)
Gape-limited predators (e.g., snakes, many fish) are not generally expected to pose a predation threat to prey that are too large for them to swallow. However, the extent to which snakes predate on prey that exceed their gape limitation remains largely unknown. We conducted the first study to investigate the influence of both prey and predator sizes on the frequency of ingestion success by snakes in a natural system. We combined survival monitoring of an avian prey species (Aplonis opaca) via radio-telemetry with a survey of the size distribution of their major predator (Boiga irregularis) on Guam. This allowed us to assess (1) the frequency of unsuccessful ingestion by the predator, (2) whether the size of the prey predicts ingestion success, (3) whether the size of the predator predicts ingestion success, and (4) the relationship between prey and predator sizes in successful ingestion attempts. We found that nearly half (47.95%) of ingestion attempts by snakes on fledgling birds were unsuccessful, and no instances where unsuccessful ingestion caused the mortality of the snake. Attempts to consume smaller fledglings were as likely to be unsuccessful as attempts to swallow larger fledglings. However, snakes that successfully ingested fledglings were among the largest snakes in the population, and larger than average conspecifics attracted to endothermic prey. The smallest snakes that successfully ingested fledglings attained remarkably high relative prey mass values for their species, consuming prey weighing up to 79.9% of their own mass. Our study indicates that B. irregularis routinely predate prey that are too large for them to successfully ingest, which causes mortality to the prey but poses little risk to the predator. The potential reward for snakes in consuming oversized prey may outweigh the inherent risks, while instances of predation that do not result in consumption may have considerable impacts on prey populations.
Migratory Ecology of Pseudoplatystoma fasciatum in the Amazon Basin Revealed by Otolith Microchemistry
Pereira, Luciana A.; Castello, Leandro; Hallerman, Eric M.; Orth, Donald J.; Duponchelle, Fabrice (MDPI, 2024-06-29)
Fish migrate for varied reasons, including to avoid predators and to access feeding, spawning, and nursery habitats, behaviors that enhance their survival and reproductive rates. However, the migratory ecology of many important fishes, especially those in river–floodplain ecosystems, remains poorly understood. One fish of the Amazon Basin whose migratory behavior is poorly understood is the catfish Pseudoplatystoma fasciatum. Here, we used otolith elemental microchemistry to characterize the migration ecology of P. fasciatum in the Amazon Basin. The main research questions of this study were: (1) does P. fasciatum move between waters with different Sr isotopic signatures (⁸⁷Sr/⁸⁶Sr) and chemical compositions? (2) What distance do they migrate? (3) Is the migration of P. fasciatum related to age? And (4) does P. fasciatum migrate mainly upstream, downstream, or in both directions? We assessed whether P. fasciatum migrates between waters with different ⁸⁷Sr/⁸⁶Sr values, comparing the Sr isotopic signature of otolith transects of each individual with the range of Sr isotopic signatures within the respective rivers. We found that 34% of the 71 fish analyzed migrated between rivers with different Sr isotopic signatures and 66% did not. The mean migration distance migrated was 126 km, with most specimens migrating between 72 and 237 km. Apparently, no fish of age one or age six or older migrated. All fish that migrated were between two and five years of age, with 20% of the specimens that migrated being two years old, 40% three years old, 30% four years old, and 20% five years old. Sixty-six percent of all individuals that migrated between rivers with different Sr signatures did so bidirectionally, while 33% moved unidirectionally. According to our definition of homing behavior in which fish migrated back to the same river where they were born, 41% of all fish that migrated displayed apparent homing behavior. Our findings provide insights into the migratory ecology of P. fasciatum, corroborating and refining knowledge reported in the literature. Our results on the migratory ecology of P. fasciatum have implications for sustainable fisheries conservation and management: conserving P. fasciatum requires habitat maintenance and suitable fishing practices in spawning and nursery habitats, and managers must consider large geographic areas for effective fishery management and conservation.
Carnivore space use behaviors reveal variation in responses to human land modification
Gorman, Nicole T.; Eichholz, Michael W.; Skinner, Daniel J.; Schlichting, Peter E.; Bastille-Rousseau, Guillaume (2024-07-18)
Background: Spatial behavior, including home-ranging behaviors, habitat selection, and movement, can be extremely informative in estimating how animals respond to landscape heterogeneity. Responses in these spatial behaviors to features such as human land modification and resources can highlight a species’ spatial strategy to maximize fitness and minimize mortality. These strategies can vary on spatial, temporal, and individual scales, and the combination of behaviors on these scales can lead to very different strategies among species. Methods: Harnessing the variation present at these scales, we characterized how species may respond to stimuli in their environments ranging from broad- to fine-scale spatial responses to human modification in their environment. Using 15 bobcat-years and 31 coyote-years of GPS data from individuals inhabiting a landscape encompassing a range of human land modification, we evaluated the complexity of both species’ responses to human modification on the landscape through their home range size, habitat selection, and functional response behaviors, accounting for annual, seasonal, and diel variation. Results: Bobcats and coyotes used different strategies in response to human modification in their home ranges, with bobcats broadly expanding their home range with increases in human modification and displaying temporal consistency in functional response in habitat selection across both season and time of day. Meanwhile, coyotes did not expand their home ranges with increased human modification, but instead demonstrated fine-scale responses to human modification with habitat selection strategies that sometimes varied by time of day and season, paired with functional responses in selection behaviors. Conclusions: These differences in response to habitat, resources, and human modification between the two species highlighted the variation in spatial behaviors animals can use to exist in anthropogenic environments. Categorizing animal spatial behavior based on these spatiotemporal responses and individual variation can help in predicting how a species will respond to future change based on their current spatial behavior.
Insights into Supporters of the MN Department of Natural Resources Nongame Wildlife Program: A Report
Jennings, Kelsey K.; Dayer, Ashley A.; Chaves, Willandia A. (2024-07-08)
Since its inception, the Minnesota Department of Natural Resources (MNDNR) Nongame Wildlife Program (MN NWP) has been crucial in protecting rare and vulnerable wildlife species in Minnesota. This work aimed to understand the demographic and motivational landscape of MN NWP supporters and inform strategies for increasing engagement and support. We conducted semi-structured focus groups and a comprehensive survey of MN NWP's current and potential supporters recruited through social media and email lists. Additionally, a targeted survey assessed the impact of various messaging strategies on potential volunteers at Minnesota parks. Our results show that while respondents generally support MN NWP's mission, lack of awareness remains a significant barrier to greater engagement, and most participants showed interest in volunteering and donating, driven by a desire to experience nature, contribute to conservation, and support biodiversity. To enhance engagement, our findings suggest that the MN NWP should focus on increasing awareness, providing clear pathways for involvement, and targeting specific demographic groups with customized messaging. These insights will support the MN NWP's efforts to expand its volunteer base and financial support and ensure the long-term success of its conservation initiatives.
Ecology and geography of Cache Valley virus assessed using ecological niche modeling
Muller, John A.; López, Krisangel; Escobar, Luis E.; Auguste, A. Jonathan (2024-06-26)
Background: Cache Valley virus (CVV) is an understudied Orthobunyavirus with a high spillover transmission potential due to its wide geographical distribution and large number of associated hosts and vectors. Although CVV is known to be widely distributed throughout North America, no studies have explored its geography or employed computational methods to explore the mammal and mosquito species likely participating in the CVV sylvatic cycle. Methods: We used a literature review and online databases to compile locality data for CVV and its potential vectors and hosts. We linked location data points with climatic data via ecological niche modeling to estimate the geographical range of CVV and hotspots of transmission risk. We used background similarity tests to identify likely CVV mosquito vectors and mammal hosts to detect ecological signals from CVV sylvatic transmission. Results: CVV distribution maps revealed a widespread potential viral occurrence throughout North America. Ecological niche models identified areas with climate, vectors, and hosts suitable to maintain CVV transmission. Our background similarity tests identified Aedes vexans, Culiseta inornata, and Culex tarsalis as the most likely vectors and Odocoileus virginianus (white-tailed deer) as the most likely host sustaining sylvatic transmission. Conclusions: CVV has a continental-level, widespread transmission potential. Large areas of North America have suitable climate, vectors, and hosts for CVV emergence, establishment, and spread. We identified geographical hotspots that have no confirmed CVV reports to date and, in view of CVV misdiagnosis or underreporting, can guide future surveillance to specific localities and species.
Flood Pulse Effects on the Growth of Pseudoplatystoma fasciatum in the Amazon Basin
Pereira, Luciana Alves; Castello, Leandro; Hallerman, Eric; Rodrigues, Edson Rubens Ferreira; Doria, Carolina Rodrigues da Costa; Duponchelle, Fabrice (MDPI, 2024-06-12)
Fish growth is a fundamental biological process driven by a multitude of intrinsic (within-individual) and extrinsic (environmental) factors that underpin individual fitness and population dynamics. Interannual variability in river hydrology regarding the intensity and duration of floods and droughts can induce interannual variations in the biotic and abiotic variables that regulate fish growth. However, the understanding of how interannual variability in river hydrology affects fish growth remains limited for most species and ecosystems. We evaluated how inter-annual hydrological variations within the Amazon River basin influence the growth of the catfish Pseudoplaystoma fasciatum. Our research questions were as follows: Do floods lead to the faster growth of P. fasciatum and droughts lead to the slower growth? And do floods and droughts affect all age classes in the same manner? We sampled 364 specimens of P. fasciatum from five sites in the Amazon basin, estimated their growth rates, and related the growth rates to indices of the intensity of floods and droughts. We fitted linear mixed-effects models to test the relationship between growth increments and hydrological indices (with F and D quantifying the intensities of floods and droughts, respectively), age as fixed effects, and basins and Fish ID as random effects. We found an inverse relationship between the increment width in the fish hard parts and hydrological indices. That is, intense floods and droughts negatively affected the growth rates. We also found that the growth of P. fasciatum was no different in years with intense and mild floods across age classes 1–5, although was different for age class 6. However, the growth of P. fasciatum was faster in years of mild droughts for all age classes. Our results showing that the growth of P. fasciatum was slower in years of intense droughts are supported by those of previous studies in the Amazon basin and elsewhere. However, our results showing for the first time that the growth of P. fasciatum is slower in years of intense flooding is the opposite of patterns found in other studies. These results thus suggest that the growth of P. fasciatum is maximized within an optimum range of hydrological conditions, where neither floods nor droughts are intense.
Inland recreational fisheries contribute nutritional benefits and economic value but are vulnerable to climate change
Lynch, Abigail J.; Embke, Holly S.; Nyboer, Elizabeth A.; Wood, Louisa E.; Thorpe, Andy; Phang, Sui C.; Viana, Daniel F.; Golden, Christopher D.; Milardi, Marco; Arlinghaus, Robert; Baigun, Claudio; Beard, T. Douglas Jr.; Cooke, Steven J.; Cowx, Ian G.; Koehn, John D.; Lyach, Roman; Potts, Warren; Robertson, Ashley M.; Schmidhuber, Josef; Weyl, Olaf L. F. (Springer Nature, 2024-05)
Inland recreational fishing is primarily considered a leisure-driven activity in freshwaters, yet its harvest can contribute to food systems. Here we estimate that the harvest from inland recreational fishing equates to just over one-tenth of all reported inland fisheries catch globally. The estimated total consumptive use value of inland recreational fish destined for human consumption may reach US$9.95 billion annually. We identify Austria, Canada, Germany and Slovakia as countries above the third quantile for nutrition, economic value and climate vulnerability. These results have important implications for populations dependent on inland recreational fishing for food. Our findings can inform climate adaptation planning for inland recreational fisheries, particularly those not currently managed as food fisheries.
Epidemiology of sarcoptic mange in a geographically constrained insular red fox population
Wails, Christy N.; Helmke, Claire C.; Black, Kathleen M.; Ramirez-Barrios, Roger; Karpanty, Sarah M.; Catlin, Daniel H.; Fraser, James D. (2024-06-06)
Background: Sarcoptic mange is a skin disease caused by the contagious ectoparasite Sarcoptes scabiei, capable of suppressing and extirpating wild canid populations. Starting in 2015, we observed a multi-year epizootic of sarcoptic mange affecting a red fox (Vulpes vulpes) population on Fire Island, NY, USA. We explored the ecological factors that contributed to the spread of sarcoptic mange and characterized the epizootic in a landscape where red foxes are geographically constrained. Methods: We tested for the presence of S. scabiei DNA in skin samples collected from deceased red foxes with lesions visibly consistent with sarcoptic mange disease. We deployed 96–100 remote trail camera stations each year to capture red fox occurrences and used generalized linear mixed-effects models to assess the affects of red fox ecology, human and other wildlife activity, and island geography on the frequency of detecting diseased red foxes. We rated the extent of visual lesions in diseased individuals and mapped the severity and variability of the sarcoptic mange disease. Results: Skin samples that we analyzed demonstrated 99.8% similarity to S. scabiei sequences in GenBank. Our top-ranked model (weight = 0.94) showed that diseased red foxes were detected more frequently close to roadways, close to territories of other diseased red foxes, away from human shelters, and in areas with more mammal activity. There was no evidence that detection rates in humans and their dogs or distance to the nearest red fox den explained the detection rates of diseased red foxes. Although detected infrequently, we observed the most severe signs of sarcoptic mange at the periphery of residential villages. The spread of visual signs of the disease was approximately 7.3 ha/week in 2015 and 12.1 ha/week in 2017. Conclusions: We quantified two separate outbreaks of sarcoptic mange disease that occurred > 40 km apart and were separated by a year. Sarcoptic mange revealed an unfettered spread across the red fox population. The transmission of S. scabiei mites in this system was likely driven by red fox behaviors and contact between individuals, in line with previous studies. Sarcoptic mange is likely an important contributor to red fox population dynamics within barrier island systems.
Southern Fox Squirrel and Eastern Gray Squirrel Interactions in a Fire-maintained Ecosystem
Guill, Marissa H.; De La Cruz, Jesse L.; Puckett, Marc; Klopfer, Scott D.; Martin, Brandon; Ford, W. Mark (2024)
Southern fox squirrels (Sciurus niger niger) have been declining due to habitat fragmentation, cover type conversion, and fire suppression in the Southeast. A decrease in growing season burns has led to hardwood encroachment and forest mesophication that benefit the competing eastern gray squirrels (S. carolinensis). In the southern Coastal Plain and Piedmont of Virginia, these pattern raises the question of whether gray squirrels are competitively excluding southern fox squirrels in these altered landscapes. From October 2019 to October 2020, we conducted continual camera trapping for southern fox squirrels and gray squirrels on the Big Woods/Piney Grove Complex (BWPGC) and at Fort Barfoot (FB) in the Coastal Plain and lower Piedmont of Virginia, respectively. Both sites are among the few areas that still contain large, intact pine savanna and mixed-pine hardwood forests in southeastern Virginia. We used two-species occupancy modeling to investigate occupancy estimates of southern fox squirrels and possible competition with gray squirrels, based on detection histories collected from camera traps on BWPGC and FB. We then conducted informed single-species occupancy modeling to estimate the necessary level-of effort (LOE) required to determine the probable absence of southern fox squirrels at sampling sites in the region. No fox squirrels were observed at FB. Our top, two species occupancy model showed that gray squirrel occupancy increased with increasing time since last burn. However, southern fox squirrel occupancy, in the absence of gray squirrels, decreased with increasing time since last burn. Gray squirrels typically inhabited hardwood-dominant closed canopy areas whereas southern fox squirrels did so at BWPGC only in the absence of gray squirrels. This suggests that southern fox squirrels are selecting areas on BWPGC based on resource needs and possibly competition with gray squirrels. A single-season occupancy model confirmed that southern fox squirrel occupancy decreased with time since the last burn. Our LOE analysis indicated that seven consecutive days of camera trapping without a detection would provide 90% confidence of the subspecies’ absence in areas burned two or more years prior to sampling. Southern fox squirrels may benefit from increased short-rotation burns to maintain or enhance pine-hardwood savannas and pine-hardwood savanna ecotones in southeastern Virginia.
Second Guessing the Maximum Likelihood Estimator Values for Bat Surveys
Ford. W. Mark; De La Cruz, Jesse L.; Thorne, Emily D.; Silvis, Alexander; Armstrong, Michael P.; King, R. Andrew (2024)
The U.S. Fish and Wildlife Service allows acoustical surveys and automated identification software to determine the presence of the endangered northern long-eared bat (Myotis septentrionalis) and Indiana bat (Myotis sodalis). Analytical software is required to assess presence probability on a site-night basis using a maximum likelihood estimator (MLE) that accounts for interspecific bat misclassification rates. The current standard for occupancy is a returned MLE P-value < 0.05 at the nightly level irrespective of the number of files identified as either northern long-eared bats or Indiana bats. These MLE P-values can vary based on presence of other bat species with similar calls and the relative proportions of all species recorded. Accordingly, there is concern that with few nightly northern long-eared bat or Indiana bat recordings or the presence of large numbers of high frequency bats, false-negative findings from a swamping effect could result. Using data collected in 2020–2021 by the U.S. Fish and Wildlife Service to set nationwide acoustic monitoring guidelines, we examined the relationship of returned software MLE P-values from 4873 site-nights of acoustic detector data relative to nightly counts of northern long-eared bats and Indiana bats, overall counts of other high-frequency bats, and habitat cover type. For both northern long-eared bats and Indiana bats, nights with one or more echolocation pass files identified as either species but above the MLE P-value threshold largely occurred where nightly counts of the target species was <15 and their proportion to the count of high-frequency bat species was low. We followed this analysis with a simulation using a known call library and observed similar patterns. Accordingly, with few nightly echolocation passes, post-hoc visual assessment following automated software identification easily could be undertaken. Evidence of swamping by other high-frequency species causing positive file identification creating false-negative or false-positives of northern long-eared bats and Indiana bats was not apparent at nightly counts of either species > 10.
Seasonal Activity Patterns of Northern Long-eared Bats on the Coastal Mid-Atlantic
De La Cruz, Jesse L.; Kalen, Nicholas J.; Barr, Elaine L.; Thorne, Emily D.; Silvis, Alexander; Reynolds, Richard J.; Ford, W. Mark (2024)
Conservation of bats declining from white-nose syndrome (WNS) impacts requires an understanding of both temporal and landscape-level habitat relationships. Traditionally, much of the research on bat ecology has focused on behavior of summer maternity colonies within species’ distribution cores, including that of the endangered northern long-eared bat (Myotis septentrionalis). To further our knowledge of this species, we evaluated multi-season activity patterns in eastern North Carolina and Virginia, including areas where populations were recently discovered. We used passive acoustic monitoring to assess relative and probable activity of northern long-eared bats from October 2016 to August 2021. Northern long-eared bat relative activity was greatest in areas containing greater proportions of woody wetlands and upland pine-dominated evergreen forests. However, the likelihood of recording northern long-eared bats was associated with smaller proportions of woody wetlands and open water resources. Furthermore, we observed a higher probability of recording northern long-eared bats during non-winter seasons. Probable activity was greatest at temperatures be- tween 10 and 25 C, potentially highlighting an optimal thermoneutral zone for the species regionally. Relative activity of northern long-eared bats on the Coastal Plain of Virginia and North Carolina was primarily driven by cover features, whereas probable activity was driven by a combination of cover features, seasonality, and temperature. Therefore, acoustical surveys for this species may be most effective when targeting woody wetlands adjacent to upland forests, particularly upland pine-dominated evergreen stands, during moderate temperatures of non-winter seasons (1 April–15 November). Moreover, conservation of a diverse mosaic of woody wetlands juxtaposed by upland forests may promote both roosting and overwintering habitat, thereby enhancing overwintering survival, maternity colony establishment, and ultimately, successful reproduction of northern long-eared bats.
Minnesota Report of Black, Indigenous, and Community Scientists of Color
Jennings, Kelsey K.; Chaves, Willandia A.; Dayer, Ashley A. (2024-05)
The Minnesota Department of Natural Resources Nongame Wildlife Program (the MN NWP) is expanding its engagement efforts to better include Black, Indigenous, and people of color (BIPOC) in conservation action. Recent studies suggest community science, or public participation in scientific research, is an effective strategy for engaging underrepresented groups. However, the demographics of community scientists remain largely homogeneous. Addressing this disparity can enhance BIPOC communities' engagement, fostering valuable relationships with scientific institutions and increasing scientific value to communities. To understand BIPOC participation in community science, we conducted focus group discussions with BIPOC-serving organizations and participants in their nature-based programs. Findings revealed that BIPOC communities face material and situational barriers to participation, such as financial constraints and negative interpersonal experiences. Participants expressed interest in community science but emphasized the need for programs that are aligned with their interests and skills and led by BIPOC individuals. Based on these insights, we recommend leveraging partnerships with existing organizations, developing relevant programs by and for community members, addressing barriers to participation, and planning for continued involvement to ensure long-term engagement. These strategies are essential for the MN NWP to effectively engage a diverse range of Minnesotans and support equity in conservation efforts.

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