0000000000631358
AUTHOR
Clayton K. Nielsen
showing 7 related works from this author
Occupancy, density, and activity patterns of a Critically Endangered leopard population on the Kawthoolei‐Thailand border
2023
Large carnivores have been largely extirpated from Southeast Asia due to deforestation, habitat fragmentation, and poaching. Estimating the density of endangered carnivore populations, and identifying relationships between species occupancy and both environmental and anthropogenic factors, is essential for effective conservation planning. Recently, the IUCN conservation status of the Indochinese leopard (Panthera pardus delacouri) was upgraded to "Critically Endangered. " We surveyed Kweekoh Wildlife Sanctuary in Kawthoolei, an area administered by the Karen ethnic group in eastern Myanmar, to quantify (1) leopard population density using spatially explicit mark-resight (SMR) models, (2) le…
Anthropogenic threats drive spatio-temporal responses of wildcat on Mt. Etna
2021
Human expansion can cause disturbance and intrusion of invasive species, which are detrimental to small carnivores. We investigated how European wildcats responded to disturbance from mushroom collectors, cattle and feral pigs in Sicily, Italy. We used detections from 76 cameras over 2 surveys (2015–2016 and 2018; camera days = 1985) to run occupancy and co-occurrence models and estimate overlap in activity patterns between species pairs. During 2015–2016, wildcats were detected at the same location with cattle, mushroom hunters and feral pigs at 14.4%, 26.3% and 17.1% of cameras. During 2018, wildcats were detected at the same location with cattle, mushroom hunters and feral pigs at 7.8%, …
Density and activity patterns of Pallas's cats, Otocolobus manul, in central Mongolia
2021
Abstract Context. The ranges of many small, at-risk felid species occur almost entirely in unprotected areas, where research efforts are minimal; hence data on their density and activity patterns are scare. Aims. We estimated density and activity patterns of Pallas’s cats on unprotected lands in central Mongolia during two periods (May–August and September–November) in 2019. Methods. We used spatially explicit capture–recapture models to estimate population density at 15.2 ± 4.8 individuals per 100 km2. Key results. We obtained 484 Pallas’s cat images from 153 detections during 4266 camera-days. We identified Pallas’s cats using pelage markings and identified 16 individuals from 64 detectio…
Show me your tail, if you have one! Is inbreeding depression occurring in wildcats (Felis silvestris silvestris) from Italy?
2022
Knowledge of genetic diversity is important to wildlife conservation because genetically depleted populations experience an increased risk of extinction. Mammalian carnivores are characterized by small and fragmented populations and low dispersal, so that genetic erosion can lead to the fixation of deleterious genes relatively quickly, leading to morphological abnormalities. Kinked tails and cowlicks are indicative of inbreeding depression and have been described in two wild cat species so far, the puma (Puma concolor) and the cheetah (Acinonyx jubatus). Here we report the first records of morphological abnormalities in five populations of the European wildcat (Felis silvestris silvestris) …
Activity overlap between mesocarnivores and prey in the Central Mongolian steppe
2021
Research on the ecology and behaviour of mesocarnivores and their prey is scant in Mongolia. We investigated activity patterns of a guild of mesocarnivores (red fox, Pallas's cat and beech marten) and their prey (Siberian marmot, Daurian pika, Brandt vole, Mongolian gerbil and Mongolian silver vole) using 21 camera traps (effort = 1155 camera days) in Central Mongolia from 25st of May to 20th August 2019. Activity patterns of mesocarnivores were cathemeral (i.e. no difference between diurnal, nocturnal and crepuscular detections, although activity peaked at sunrise). Among prey, the Siberian marmot and the Daurian pika were diurnal, whereas the Mongolian gerbil and the Mongolian silver vole…
Record of a 10-year old European Wildcat Felis silvestris silvestris Schreber, 1777 (Mammalia: Carnivora: Felidae) from Mt. Etna, Sicily, Italy
2020
Longevity data for wild felids are lacking in the literature. Here we report a camera trap recapture of a European Wildcat Felis silvestris at Mt. Etna in Sicily, Italy after nine years. This individual was clearly identifiable as its tail ended with a white ring rather than the typical black ring and had a unique shape of the dorsal stripe. At first capture on 26 May 2009, this cat was assessed as an adult, so that the likely minimum age of this individual at the time of recapture on 10 June 2018 must have been be at least 10 years. This finding represents the oldest known European Wildcat in the wild and provides insight into age structure in wildcat populations.
Determinants of jaguar occupancy at the northern range edge
2020
Identifying factors promoting jaguar (Panthera onca) occupancy is crucial for planning effective conservation and management actions that can contribute to long-term population viability. We used camera-trapping and modeled factors affecting detection and occupancy for jaguars in Sonora at 149 sites during August-November 2008 and 2009. We measured 24 covariates presumed to affect detection (n = 6) and occupancy (n = 18) at camera sites, including sampling period and various habitat characteristics. We obtained 29 jaguar detections at 19 sites (naive occupancy = 0.12) in 5455 trap-days of effort. Jaguar detectability (p = 0.16 +/- 0.05) was negatively affected by human presence and varied b…