Monitoring sun bears and Asiatic black bears with remotely sensed predictors to inform conservation management

Lorraine Scotson,Steven Ross,Todd W Arnold

doi:10.1017/s0030605318001187

Lorraine Scotson, Steven Ross + Show 1 more

Open Access

https://doi.org/10.1017/s0030605318001187

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Abstract

AbstractAsiatic black bear Ursus thibetanus and sun bear Helarctos malayanus populations are declining throughout South-east Asia as a result of habitat loss and human disturbance. Knowledge of the distribution and status of each species is limited and largely anecdotal. Range maps are coarse, compiled by expert opinion, and presence or absence is unknown over large portions of South-east Asia. These two species co-occur in Lao People's Democratic Republic and may be faring better there than in neighbouring countries. During 2010–2013 we searched for bear sign along 99 transects within eight study sites throughout Lao. To explore countrywide relative abundance and habitat suitability, we modelled bear sign as a log-linear function of biological and anthropogenic predictors that were associated with habitat assemblages and human disturbance. Bears favored higher elevations and rugged terrain in areas less accessible to humans, and were most abundant in the north and east of Lao. Suitable habitats were rare in the southern lowland plains where bear abundance was relatively low. Our model predicted that Nam Et–Phou Louey National Protected Area had the largest areas of suitable bear habitat, followed by the Nakai-Nam Teun and Nam Ha National Protected Areas. Using transects to survey for bear sign, we created a replicable geographical information system based assessment tool for bears in Lao that can be used to identify conservation opportunities and monitor changes in bear distribution over time.

Highlights

Lao People’s Democratic Republic may be a core conservation area for the Asiatic black bear Ursus thibetanus and sun bear Helarctos malayanus
We modelled bear sign as a log-linear function of ecological and anthropogenic predictors using a single a priori mixed model selected based on sample size and degrees of freedom (Fieberg et al, ; Giudice et al, )
We evaluated models with the intraclass correlation coefficient (ICC), which is the ratio of the between-cluster variance (12) to the total variance and is the proportion of total variance in the response that is accounted for by clustering of

Summary

Introduction

Lao People’s Democratic Republic may be a core conservation area for the Asiatic black bear Ursus thibetanus and sun bear Helarctos malayanus. Bears in Lao are threatened by poaching and habitat loss. Commercial trade of Asian bears is considered one of the biggest threats to wild populations, with trade occurring domestically and internationally with China, Thailand and Viet Nam (Foley et al, ; Garshelis & Steinmetz, ; Scotson et al, a). Asian bears are threatened by high rates of deforestation (Sodhi et al, ; Miettinen et al, ). Habitat loss is estimated to have reduced Lao’s bear population by c. Asiatic black bears and sun bears are categorized as Vulnerable on the IUCN Red List, with populations projected to decline globally by . Asiatic black bears and sun bears are categorized as Vulnerable on the IUCN Red List, with populations projected to decline globally by . % in the + years (Garshelis & Steinmetz, ; Scotson et al, a)

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