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Tiffin HS, Brown JD, Ternent M, Snavely B, Carrollo E, Kibe E, Buderman FE, Mullinax JM, Machtinger ET. Resolution of Clinical Signs of Sarcoptic Mange in American Black Bears (Ursus americanus), in Ivermectin-Treated and Nontreated Individuals. J Wildl Dis 2024; 60:434-447. [PMID: 38305090 DOI: 10.7589/jwd-d-23-00134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Accepted: 10/31/2023] [Indexed: 02/03/2024]
Abstract
The parasitic mite Sarcoptes scabiei causes mange in nearly 150 species of mammals by burrowing under the skin, triggering hypersensitivity responses that can alter animals' behavior and result in extreme weight loss, secondary infections, and even death. Since the 1990s, sarcoptic mange has increased in incidence and geographic distribution in Pennsylvania black bear (Ursus americanus) populations, including expansion into other states. Recovery from mange in free-ranging wildlife has rarely been evaluated. Following the Pennsylvania Game Commission's standard operating procedures at the time of the study, treatment consisted of one subcutaneous injection of ivermectin. To evaluate black bear survival and recovery from mange, from 2018 to 2020 we fitted 61 bears, including 43 with mange, with GPS collars to track their movements and recovery. Bears were collared in triplicates according to sex and habitat, consisting of one bear without mange (healthy control), one scabietic bear treated with ivermectin when collared, and one untreated scabietic bear. Bears were reevaluated for signs of mange during annual den visits, if recaptured during the study period, and after mortality events. Disease status and recovery from mange was determined based on outward gross appearance and presence of S. scabiei mites from skin scrapes. Of the 36 scabietic bears with known recovery status, 81% fully recovered regardless of treatment, with 88% recovered with treatment and 74% recovered without treatment. All bears with no, low, or moderate mite burdens (<16 mites on skin scrapes) fully recovered from mange (n=20), and nearly half of bears with severe mite burden (≥16 mites) fully recovered (n=5, 42%). However, nonrecovered status did not indicate mortality, and mange-related mortality was infrequent. Most bears were able to recover from mange irrespective of treatment, potentially indicating a need for reevaluation of the mange wildlife management paradigm.
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Affiliation(s)
- Hannah S Tiffin
- Department of Entomology, Pennsylvania State University, 4 Chemical Ecology Laboratory, University Park, Pennsylvania 16802, USA
| | - Justin D Brown
- Department of Veterinary & Biomedical Sciences, Pennsylvania State University, 108D AVBS Building, Shortlidge Rd., University Park, Pennsylvania 16802, USA
| | - Mark Ternent
- Pennsylvania Game Commission, 2001 Elmerton Ave., Harrisburg, Pennsylvania 17110, USA
| | - Brandon Snavely
- Pennsylvania Game Commission, 2001 Elmerton Ave., Harrisburg, Pennsylvania 17110, USA
| | - Emily Carrollo
- Pennsylvania Game Commission, 2001 Elmerton Ave., Harrisburg, Pennsylvania 17110, USA
| | - Ethan Kibe
- Pennsylvania Game Commission, 2001 Elmerton Ave., Harrisburg, Pennsylvania 17110, USA
| | - Frances E Buderman
- Department of Ecosystem Science & Management, Pennsylvania State University, 401 Forest Resources Building, University Park, Pennsylvania 16802, USA
| | - Jennifer M Mullinax
- Department of Environmental Science & Technology, University of Maryland, 1433 Animal Science Building, 8127 Regents Dr., College Park, Maryland 20742, USA
| | - Erika T Machtinger
- Department of Entomology, Pennsylvania State University, 4 Chemical Ecology Laboratory, University Park, Pennsylvania 16802, USA
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Murphy A, Diefenbach DR, Ternent M, Lovallo M, Miller D. Threading the needle: How humans influence predator-prey spatiotemporal interactions in a multiple-predator system. J Anim Ecol 2021; 90:2377-2390. [PMID: 34048031 DOI: 10.1111/1365-2656.13548] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 05/17/2021] [Indexed: 12/01/2022]
Abstract
Perceived predation risk and the resulting antipredator behaviour varies across space, time and predator identity. Communities with multiple predators that interact and differ in their use of space, time of activity and hunting mode create a complex landscape for prey to avoid predation. Anthropogenic presence and disturbance have the potential to shift interactions among predators and prey and the where and when encounters occur. We examined how white-tailed deer Odocoileus virginianus fawn spatiotemporal antipredator behaviour differed along an anthropogenic disturbance gradient that had black bears Ursus americanus, coyotes Canis latrans, bobcats Lynx rufus and humans present. We quantified (a) spatial co-occurrence in species distributions, (b) temporal overlap across the diel cycle and (c) spatiotemporal associations between humans, bears, coyotes, bobcats, adult male deer and fawns. We also examined how deer vigilance behaviour changed across the anthropogenic disturbance gradient and survey duration. Anthropogenic disturbance influenced spatiotemporal co-occurrence across multiple scales, often increasing spatiotemporal overlap among species. In general, species' spatial co-occurrence was neutral or positive in anthropogenically disturbed environments. Bears and fawns, coyotes and adult male deer, and bobcats and fawns all had higher temporal overlap in the agriculture-development matrix sites. In addition, factors that influenced deer vigilance (e.g. distance to forest edge and predator relative abundance) in the agriculture-development matrix sites did not in the forest matrix site. By taking into account the different antipredator behaviours that can be detected and the different scales these behaviours might occur, we were able to gain a more comprehensive picture of how humans reduce available niche space for wildlife, creating the neutral and positive spatiotemporal associations between species that studies have been seeing in more disturbed areas.
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Affiliation(s)
- Asia Murphy
- Intercollege Graduate Degree Program in Ecology, Pennsylvania State University, University Park, PA, USA
| | - Duane R Diefenbach
- U.S. Geological Survey, Pennsylvania Cooperative Fish and Wildlife Research Unit, Pennsylvania State University, University Park, PA, USA
| | - Mark Ternent
- Pennsylvania Game Commission, Harrisburg, PA, USA
| | - Matt Lovallo
- Pennsylvania Game Commission, Harrisburg, PA, USA
| | - David Miller
- Department of Ecosystem Science and Management, Pennsylvania State University, University Park, PA, USA
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Peltier SK, Brown JD, Ternent M, Niedringhaus KD, Schuler K, Bunting EM, Kirchgessner M, Yabsley MJ. Genetic Characterization of Sarcoptes scabiei from Black Bears (Ursus americanus) and Other Hosts in the Eastern United States. J Parasitol 2017. [PMID: 28639466 DOI: 10.1645/17-26] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Since the early 1990s there has been an increase in the number of cases and geographic expansion of severe mange in the black bear (Ursus americanus) population in Pennsylvania. Although there are 3 species of mites associated with mange in bears, Sarcoptes scabiei has been identified as the etiologic agent in these Pennsylvania cases. Historically, S. scabiei-associated mange in bears has been uncommon and sporadic, although it is widespread and relatively common in canid populations. To better understand this recent emergence of sarcoptic mange in bears in Pennsylvania and nearby states, we genetically characterized S. scabiei samples from black bears in the eastern United States. These sequences were compared with newly acquired S. scabiei sequences from wild canids (red fox [Vulpes vulpes] and coyote [Canis latrans]) and a porcupine (Erethizon dorsatum) from Pennsylvania and Kentucky and also existing sequences in GenBank. The internal transcribed spacer (ITS)-2 region and cytochrome c oxidase subunit 1 (cox1) gene were amplified and sequenced. Twenty-four ITS-2 sequences were obtained from mites from bears (n = 16), red fox (n = 5), coyote (n = 2), and a porcupine. The sequences from bear samples were identical to each other or differed only at polymorphic bases, whereas S. scabiei from canids were more variable, but 2 were identical to S. scabiei sequences from bears. Eighteen cox1 sequences obtained from mites from bears represented 6 novel haplotypes. Phylogenetic analysis of cox1 sequences revealed 4 clades: 2 clades of mites of human origin from Panama or Australia, a clade of mites from rabbits from China, and a large unresolved clade that included the remaining S. scabiei sequences from various hosts and regions, including sequences from the bears from the current study. Although the cox1 gene was more variable than the ITS-2, phylogenetic analyses failed to detect any clustering of S. scabiei from eastern U.S. hosts. Rather, sequences from black bears grouped into a large clade that included S. scabiei from numerous hosts from Europe, Asia, Africa, and Australia. Collectively, these data suggest that the increasing number of S. scabiei cases in northeastern black bears is not due to the emergence and expansion of a single parasite strain.
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Affiliation(s)
- Sarah K Peltier
- * Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602
| | | | | | - Kevin D Niedringhaus
- * Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602
| | | | | | | | - Michael J Yabsley
- * Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602
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Dubey JP, Brown J, Ternent M, Verma SK, Hill DE, Cerqueira-Cézar CK, Kwok OC, Calero-Bernal R, Humphreys JG. Seroepidemiologic study on the prevalence of Toxoplasma gondii and Trichinella spp. infections in black bears (Ursus americanus) in Pennsylvania, USA. Vet Parasitol 2016; 229:76-80. [DOI: 10.1016/j.vetpar.2016.09.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 08/11/2016] [Accepted: 09/18/2016] [Indexed: 11/26/2022]
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