Identification errors in camera-trap studies result in systematic population overestimation

AbstractReliable 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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Status of the mountain ungulate prey of the Endangered snow leopard Panthera uncia in the Tost Local Protected Area, South Gobi, Mongolia

Oryx ◽

10.1017/s0030605314001203 ◽

2015 ◽

Vol 50 (2) ◽

pp. 214-219 ◽

Cited By ~ 8

Author(s):

Lkhagvasumberel Tumursukh ◽

Kulbhushansingh R. Suryawanshi ◽

Charudutt Mishra ◽

Thomas M. McCarthy ◽

Bazartseren Boldgiv

Keyword(s):

Protected Area ◽

Nature Reserve ◽

Camera Trap ◽

Snow Leopard ◽

Wild Ungulates ◽

Mountainous Regions ◽

Demographic Surveys ◽

Snow Leopards ◽

Ovis Ammon ◽

Panthera Uncia

AbstractThe availability of wild prey is a critical predictor of carnivore density. However, few conservation programmes have focused on the estimation and monitoring of wild ungulate populations and their trends, especially in the remote mountains of Central Asia. We conducted double-observer surveys to estimate the populations of ibex Capra sibirica and argali Ovis ammon in the mountainous regions of Tost Local Protected Area, South Gobi province, Mongolia, which is being considered for designation as a Nature Reserve. We also conducted demographic surveys of the more abundant ibex to examine their sex-ratio and the survival of young during 2012–2013. The estimated ibex population remained stable in 2012 and 2013 and the estimated argali population increased from 108 in 2012 to 230 in 2013. The biomass of wild ungulates was c. 6% that of livestock. Mortality in young ibex appeared to increase after weaning, at the age of 12 months. We estimated the population of wild ungulates was sufficient to support 14–18 adult snow leopards Panthera uncia. The adult snow leopard population in our study area during 2012–2013, estimated independently using camera-trap-based mark–recapture methods, was 12–14. Based on our results we identify the Tost Local Protected Area as an important habitat for the conservation of these ungulates and their predator, the Endangered snow leopard, and recommend elevation of its status to a Nature Reserve.

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Faculty Opinions recommendation of Low-coverage vaccination strategies for the conservation of endangered species.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1046758.496769 ◽

2006 ◽

Author(s):

James Crowe

Keyword(s):

Endangered Species ◽

Vaccination Strategies ◽

Conservation Of Endangered Species ◽

Low Coverage

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Faculty Opinions recommendation of Are patterns of density dependence in the Global Population Dynamics Database driven by uncertainty about population abundance?

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.13371997.14742108 ◽

2011 ◽

Author(s):

Vlastimil Krivan ◽

Ludek Berec

Keyword(s):

Population Dynamics ◽

Density Dependence ◽

Population Abundance ◽

Global Population

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Conservation of snow leopards: spill-over benefits for other carnivores?

Oryx ◽

10.1017/s0030605315001040 ◽

2015 ◽

Vol 50 (2) ◽

pp. 239-243 ◽

Cited By ~ 10

Author(s):

Justine S. Alexander ◽

Jeremy J. Cusack ◽

Chen Pengju ◽

Shi Kun ◽

Philip Riordan

Keyword(s):

Red Fox ◽

Spatial Scales ◽

Camera Trap ◽

Snow Leopard ◽

Lynx Lynx ◽

Eurasian Lynx ◽

Detection Rates ◽

Cuon Alpinus ◽

Sign Surveys ◽

Snow Leopards

AbstractIn high-altitude settings of Central Asia the Endangered snow leopard Panthera uncia has been recognized as a potential umbrella species. As a first step in assessing the potential benefits of snow leopard conservation for other carnivores, we sought a better understanding of the presence of other carnivores in areas occupied by snow leopards in China's Qilianshan National Nature Reserve. We used camera-trap and sign surveys to examine whether other carnivores were using the same travel routes as snow leopards at two spatial scales. We also considered temporal interactions between species. Our results confirm that other carnivores, including the red fox Vulpes vulpes, grey wolf Canis lupus, Eurasian lynx Lynx lynx and dhole Cuon alpinus, occur along snow leopard travel routes, albeit with low detection rates. Even at the smaller scale of our camera trap survey all five carnivores (snow leopard, lynx, wolf, red fox and dhole) were observed. Kernel density estimates suggested a high degree of temporal overlap between the snow leopard and the fox, and the snow leopard and the lynx, as indicated by high overlap coefficient estimates. There is an opportunity to consider protective measures at the local scale that would benefit various species simultaneously. However, it should also be recognized that snow leopard conservation efforts could exacerbate human–wildlife conflicts through their protective effect on other carnivore species.

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Multiple ocular coloboma (MOC) in snow leopards (Panthera uncia) Clinical report, pedigree analysis, chromosome investigations and serum protein studies

Hereditas ◽

10.1111/j.1601-5223.1985.tb00505.x ◽

2008 ◽

Vol 103 (2) ◽

pp. 221-229 ◽

Cited By ~ 14

Author(s):

ULLA GRIPENBERG ◽

LEIF BLOMQVIST ◽

PEKKA PAMILO ◽

VERONICA SÖDERLUND ◽

AHTI TARKKANEN ◽

...

Keyword(s):

Serum Protein ◽

Pedigree Analysis ◽

Clinical Report ◽

Snow Leopards ◽

Panthera Uncia

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A multifrequency method to classify and evaluate fisheries acoustics data

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f06-126 ◽

2006 ◽

Vol 63 (10) ◽

pp. 2225-2235 ◽

Cited By ~ 47

Author(s):

J Michael Jech ◽

William L Michaels

Keyword(s):

Clupea Harengus ◽

Biological Information ◽

Classification Algorithms ◽

Atlantic Herring ◽

Population Abundance ◽

Acoustic Data ◽

Video Images ◽

Abundance Estimates ◽

Fisheries Acoustics ◽

Acoustic Surveys

Acoustic surveys have been conducted on Georges Bank from 1998 to present to estimate Atlantic herring (Clupea harengus) population abundance. Acoustic data were collected with a 12 or 18, 38, and 120 kHz Simrad EK500 scientific echo sounder. A pelagic trawl and underwater video images were used to collect biological information and to verify the species composition of acoustic backscatter. A multifrequency classification method was developed to improve the efficiency and accuracy of classifying species from acoustic echograms. In this method, a volume backscatter (Sv) threshold was applied equivalently to all echograms, and then a composite echogram was created based on which frequencies had Sv greater than or less than the Sv threshold. The results of this method were compared with the standard method of visually scrutinizing regions, and metrics were developed to evaluate the accuracy of classification algorithms relative to current methods, as well as to assess the effects of classification methods on population abundance estimates. In general, this method matched visually scrutinized Atlantic herring regions, but with consistent biases in classifying 38 kHz backscatter. The metrics highlighted spatial and temporal changes in the acoustic landscape, which may be indicative of intra- and inter-annual biological changes.

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