Publications by authors named "Clayton K Nielsen"

SNAPSHOT USA is a multicontributor, long-term camera trap survey designed to survey mammals across the United States. Participants are recruited through community networks and directly through a website application (https://www.snapshot-usa.

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Cytauxzoon felis is a tick-transmitted intraerythrocytic apicomplexan infecting felids in the southeastern and midwestern United States. Bobcats (Lynx rufus) are the natural wildlife reservoir of C. felis, where in enzootic areas prevalence can reach 100%.

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Natal habitat preference induction (NHPI) occurs when animals exhibit a preference for new habitat that is similar to that which they experienced in their natal environment, potentially leading to post-dispersal success. While the study of NHPI is typically focused on post-settlement home ranges, we investigated how this behavior may manifest during extra-home range movements (EHRMs), both to identify exploratory prospecting behavior and assess how natal habitat cues may influence path selection before settlement. We analyzed GPS collar relocation data collected during 79 EHRMs made by 34 juvenile and subadult white-tailed deer () across an agricultural landscape with highly fragmented forests in Illinois, USA.

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Species coexistence is governed by availability of resources and intraguild interactions including strategies to reduce ecological overlap. Gray foxes are dietary generalist mesopredators expected to benefit from anthropogenic disturbance, but populations have declined across the midwestern USA, including severe local extirpation rates coinciding with high coyote and domestic dog occurrence and low red fox occurrence. We used data from a large-scale camera trap survey in southern Illinois, USA to quantify intraguild spatial and temporal interactions among the canid guild including domestic dogs.

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Species distribution models (SDMs) have become an essential tool for the management and conservation of imperiled species. However, many at-risk species are rare and characterized by limited data on their spatial distribution and habitat relationships. This has led to the development of SDMs that integrate multiple types and sources of data to leverage more information and provide improved predictions of habitat associations.

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Following the discontinuation of commercial polybrominated diphenyl ether (PBDE) mixtures, a variety of alternative flame retardants (FRs) have been developed and employed. To understand the contamination status of these emerging FRs in marine fish and wildlife, we investigated their bioaccumulation in four shark species, including shortfin mako shark (Isurus oxyrhinchus; n = 26), porbeagle (Lamna nasus; n = 4), sandbar shark (Carcharhinus plumbeus; n = 6), and common thresher (Alopias vulpinus; n = 4), from coastal and offshore waters of the western North Atlantic Ocean. Median concentrations of emerging FRs, including dechlorane analogues (i.

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Originally endemic to South America, the nine-banded armadillo (Dasypus novemcinctus) has recently expanded its range northward to Illinois. With this range expansion comes concern regarding potential incoming pathogens; our research, conducted during 2012-2020, consisted of screening armadillos for the presence of helminths, Trypanosoma cruzi, and Mycobacterium leprae. We screened for the presence of T.

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Protists of the genus Cytauxzoon infect a wide variety of wild and domestic felids worldwide. While the American Cytauxzoon felis has been well described, data on the European isolates of Cytauxzoon are still scant. The aim of the current study was to determine the genetic diversity of European Cytauxzoon spp.

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Cytauxzoon felis is a pathogen responsible for cytauxzoonosis, a highly fatal disease in domestic cats. Although most studies of C. felis have focused on this parasite in domestic cats, bobcats are the reservoir host.

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The present work represents a comprehensive study of in utero maternal transfer of legacy and emerging flame retardants (FRs) in marine predators. We analyzed liver tissues from pregnant sharks of five viviparous species, including blacknose shark ( Carcharhinus acronotus; n = 12), blacktip shark ( Carcharhinus limbatus; n = 2), bonnethead ( Sphyrna tiburo; n = 2), Atlantic sharpnose shark ( Rhizoprionodon terraenovae; n = 2), and spinner shark ( Carcharhinus brevipinna; n = 2), as well as their embryos ( n = 84 in total from five species), collected from the western North Atlantic Ocean. Concentrations of frequently detected emerging FRs in adult female blacknose sharks were determined to be 6.

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Cytauxzoon felis, and the resulting disease, cytauxzoonosis, is an emerging threat to domestic cats in the Midwest and Southeastern United States. Domestic cats that survive cytauxzoonosis (or are subclinically infected) are chronically infected with C. felis, yet to date, there is no information relative to chronic infections in bobcats, the natural reservoir.

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Background: The northern limits of Trypanosoma cruzi across the territory of the United States remain unknown. The known vectors Triatoma sanguisuga and T. lecticularia find their northernmost limits in Illinois; yet, earlier screenings of those insects did not reveal the presence of the pathogen, which has not been reported in vectors or reservoir hosts in this state.

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Raccoons (Procyon lotor) are one of the most widespread and abundant mammals in North America. To evaluate the suitability of using raccoons as bioindicator species, we analyzed liver tissues (n = 32) collected from 2013 to 2015 for the presence of polybrominated diphenyl ethers (PBDEs) and Dechloranes. ∑PBDE concentrations ranged from 19.

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Cytauxzoon felis is an intraerythrocytic apicomplexan of felids enzootic in the southeastern United States. In domestic cats (Felis catus), this parasite can result in the highly fatal disease cytauxzoonosis or bobcat fever. Bobcats (Lynx rufus) are the wild animal reservoir host.

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Intraspecific social behavior can be influenced by both intrinsic and extrinsic factors. While much research has focused on how characteristics of individuals influence their roles in social networks, we were interested in the role that landscape structure plays in animal sociality at both individual (local) and population (global) levels. We used female white-tailed deer (Odocoileus virginianus) in Illinois, USA, to investigate the potential effect of landscape on social network structure by weighting the edges of seasonal social networks with association rate (based on proximity inferred from GPS collar data).

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In response to the restrictions of polybrominated diphenyl ether (PBDE) flame retardants in various consumer products, alternative halogenated flame retardants have been subjected to increased use. Compared to aquatic ecosystems, relatively little information is available on the contamination of alternative flame retardants in terrestrial ecosystems, especially with regards to mammalian wildlife. In this study we used a top terrestrial carnivore, the bobcat (Lynx rufus), as a unique biomonitoring species for assessing flame retardant contamination in the Midwestern United States (U.

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The use of camera traps as a tool for studying wildlife populations is commonplace. However, few have considered how the number of detections of wildlife differ depending upon the number of camera traps placed at cameras-sites, and how this impacts estimates of occupancy and community composition. During December 2015-February 2016, we deployed four camera traps per camera-site, separated into treatment groups of one, two, and four camera traps, in southern Illinois to compare whether estimates of wildlife community metrics and occupancy probabilities differed among survey methods.

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Organohalogenated compounds (OHCs) such as polychlorinated biphenyls (PCBs) are of global concern due to their environmental persistence, bioaccumulative potential, and adverse effects on humans and wildlife. We investigated the concentrations of PCBs in the liver tissues of bobcats (Lynx rufus) sampled in Illinois during 2013. Concentrations of ∑PCBs ranged from 76.

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In social species, individuals contact members of the same group much more often than those of other groups, particularly for contacts that could directly transmit disease agents. This disparity in contact rates violates the assumptions of simple disease models, hinders disease spread between groups, and could decouple disease transmission from population density. Social behavior of white-tailed deer has important implications for the long-term dynamics and impact of diseases such as bovine tuberculosis and chronic wasting disease (CWD), so expanding our understanding of their social system is important.

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Helminth parasites of wild and domestic felines pose a direct or potential threat to human health. Since helminths depend on multiple environmental factors that make their transmission possible, it is imperative to predict the areas where these parasites may complete the transmission to potential hosts. Bobcats, Lynx rufus (Schreberer), are the most abundant and widely-distributed wild felid species in North America.

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Social interactions can influence infectious disease dynamics, particularly for directly transmitted pathogens. Therefore, reliable information on contact frequency within and among groups can better inform disease modeling and management. We compared three methods of assessing contact patterns: (1) space-use overlap (volume of interaction [VI]), (2) direct contact rates measured by simultaneous global positioning system (GPS) locations (<10 m apart), and (3) direct contact rates measured by proximity loggers (PLs; 1-m detection) among female white-tailed deer (Odocoileus virginianus).

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A total of 6257 helminths of 19 taxa were recovered from the digestive tract and lungs of 67 bobcats in Illinois. Infections caused by Alaria mustelae, Diphyllobothrium latum, and Macracanthorhynchus ingens are reported for the first time in bobcats. From all the taxa recovered, only three species occurred in high prevalence and caused intense infections: Taenia rileyi, Alaria marcianae, and Toxocara cati, with prevalence and mean intensity of 70% and 6; 42% and 193, and 25% and 14 individuals, respectively.

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