Use of spatial capture–recapture to estimate density of Andean bears in northern Ecuador

  title={Use of spatial capture–recapture to estimate density of Andean bears in northern Ecuador},
  author={Santiago Molina and Angela K. Fuller and Dana J. Morin and J. Andrew Royle},
  pages={117 - 126}
Abstract The Andean bear (Tremarctos ornatus) is the only extant species of bear in South America and is considered threatened across its range and endangered in Ecuador. Habitat loss and fragmentation is considered a critical threat to the species, and there is a lack of knowledge regarding its distribution and abundance. The species is thought to occur at low densities, making field studies designed to estimate abundance or density challenging. We conducted a pilot camera-trap study to… 

An Andean bear population hotspot in Northern Peru

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Toward reliable population estimates of wolves by combining spatial capture-recapture models and non-invasive DNA monitoring

DNA monitoring combined with SCR may be a cost-effective way to generate reliable population estimates for large carnivores at regional scales, especially for endangered species or populations under game management.

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Andean bear (Tremarctos ornatus) population density and relative abundance at the buffer zone of the Chingaza National Natural Park, cordillera oriental of the colombian andes

The Andean bear (Tremarctos ornatus) population density and relative abundance within the Chingaza Massif were assessed between September 2015 and May 2016. One hundred seventeen (117) camera traps

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Abstract: Natal dens are critical for reproduction in bears, yet we know virtually nothing of Andean bear (Tremarctos ornatus) denning ecology, nor whether female Andean bears select dens or den

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This work demonstrates using simulations that SMR alone can produce biased and imprecise density estimates with sparse data and/or when few individuals are marked, and provides efficient SMR algorithms that accommodate all SMR sample types, interspersed marking and sighting periods, and any number of identity covariates using the 2-dimensional individual by trap data in conjunction with precomputed constraint matrices.

Tremarctos ornatus (Carnivora: Ursidae)

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Spatial Capture-Recapture for Categorically Marked Populations with An Application to Genetic Capture-Recapture

The unmarked SCR model is extended to incorporate partially identifying covariates which reduce the level of uncertainty in individual identity, increasing the reliability and precision of density estimates, and allowing reliable density estimation in scenarios with higher IDI values and with more sparse data.

Spatial capture–recapture with random thinning for unidentified encounters

A “random thinning” SCR model that utilizes encounters of both known and unknown identity samples using a natural mechanistic dependence between samples arising from a single observation model is described and can improve density estimation for noninvasive sampling studies for low‐density populations with low rates of individual identification.



A preliminary density estimate for Andean bear using camera-trapping methods

Abstract Andean (spectacled) bears (Tremarctos ornatus) are threatened across most of their range in the Andes. To date no field-based density estimations are available for this species. We present a

Andean bear density and abundance estimates — How reliable and useful are they?

Abstract Few attempts have been made to estimate numbers and densities of Andean bears (Tremarctos ornatus). It is understandable that the many challenges involved in these efforts have made it

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An application of using capture-recapture to develop a model of animal density using a least-cost path model for individual encounter probability that accounts for non-Euclidean connectivity in a highly structured network is demonstrated.


No reliable estimates exist for populations of Andean bears (Tremarctos omatus). They occupy >260,000 km2 in 5 Andean countries, and if their densities are comparable to those of North American black

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Abstract We sought to identify priority areas for the conservation of Andean bear (Tremarctos ornatus) habitat in the northern portion of the eastern Andean cordillera in Ecuador. The study area

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Improved the knowledge of the ecology of this species in Ecuador was improved by examining Andean bear diets in the Oyacachi area and the habitats that provide those foods.

Spatial Capture–Recapture: A Promising Method for Analyzing Data Collected Using Artificial Cover Objects

It is demonstrated the utility of the application of SCR for studies of reptiles and amphibians by analyzing capture–recapture data from Red-Backed Salamanders, Plethodon cinereus, collected using artificial cover boards.

Andean bear home ranges in the Intag region, Ecuador

All bears in this study showed some degree of home range overlap, indicating intra-specific tolerance, and k-NNCH analysis was considered the best method for estimating Andean bear home ranges in fragmented landscapes such as those across the study site.

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Abstract We review the state of knowledge regarding conflicts between the Andean bear (Tremarctos ornatus) and livestock. Information was gathered from the current known geographic range of the