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Johansson, O., Samelius, G., Wikberg, E, Chapron, G., Mishra, C., Low, M. (2020). Identification errors in camera- trap studies result in systematic population overestimation. Scientific Reports, 10(6393), 1–10.
Abstract: Reliable assessments of animal abundance are key for successful conservation of endangered species. For elusive animals with individually-unique markings, camera-trap surveys are a benchmark standard for estimating local and global population abundance. Central to the reliability of resulting abundance estimates is the assumption that individuals are accurately identified from photographic captures. To quantify the risk of individual misidentification and its impact on population abundance estimates we performed an experiment under controlled conditions in which 16 captive snow leopards (Panthera uncia) were camera-trapped on 40 occasions and eight observers independently identified individuals and recaptures. Observers misclassified 12.5% of all capture occasions, resulting in systematically inflated population abundance estimates on average by one third (mean ± SD = 35 ± 21%). Our results show that identifying individually-unique individuals from camera-trap photos may not be as reliable as previously believed, implying that elusive and endangered species could be less abundant than current estimates indicate.
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Johansson, O., Ullman, K., Lkhagvajav, P., Wiseman, M.,
Malmsten, J., Leijon, M. (2020). Detection and Genetic Characterization of Viruses Present in
Free-Ranging Snow Leopards Using Next-Generation Sequencing. Frontiers in Veterinary Science, 7(645), 1–9.
Abstract: Snow leopards inhabit the cold, arid environments of the high
mountains of South and Central Asia. These living conditions likely
affect the abundance and composition of microbes with the capacity to
infect these animals. It is important to investigate the microbes that
snow leopards are exposed to detect infectious disease threats and
define a baseline for future changes that may impact the health of this
endangered felid. In this work, next-generation sequencing is used to
investigate the fecal (and in a few cases serum) virome of seven snow
leopards from the Tost Mountains of Mongolia. The viral species to which
the greatest number of sequences reads showed high similarity was
rotavirus. Excluding one animal with overall very few sequence reads,
four of six animals (67%) displayed evidence of rotavirus infection. A
serum sample of a male and a rectal swab of a female snow leopard
produced sequence reads identical or closely similar to felid
herpesvirus 1, providing the first evidence that this virus infects snow
leopards. In addition, the rectal swab from the same female also
displayed sequence reads most similar to feline papillomavirus 2, which
is the first evidence for this virus infecting snow leopards. The rectal
swabs from all animals also showed evidence for the presence of small
circular DNA viruses, predominantly Circular Rep-Encoding
Single-Stranded (CRESS) DNA viruses and in one case feline anellovirus.
Several of the viruses implicated in the present study could affect the
health of snow leopards. In animals which are under environmental
stress, for example, young dispersing individuals and lactating females,
health issues may be exacerbated by latent virus infections.
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