'Time of photo-capture provides valuable data to study tigers'

A new method developed by experts incorporates time of photo-capture to estimate abundance and spatial distribution of tigers and helps represent data closer to reality, a statement said on Monday.

Seventy percent of wild tigers are concentrated in less than six percent of remaining habitats worldwide. Science-based management is critical for tiger conservation. Spatial capture-recapture (SCR) model analysis is often used to estimate tiger abundance

A new study led by Robert Dorazio of the United States Geological Survey, and co-authored by Ullas Karanth, Wildlife Conservation Society Director for Science in Asia, exploits all information provided by the SCR data, obtained using continuous-time recorders i.e. camera-traps.

Dates and times of animal detections are fundamental considerations to designing and implementing a conservation strategy.

Traditionally time-data is discarded during analysis despite availability of the information in camera-trap data.

The new model estimates the spatial distribution and abundance of animals by making full use of location of photo-capture data and time of photo-capture data - which is a significant advance from traditional SCR analysis which uses only location of photo-capture data.

Dorazio said: "Modeling photo-capture times of tigers and other large carnivores uses all of the information in the data and gives us a chance to learn more about the behaviors and movements of these animalsa" information that is crucial to their conservation."

"We are now able to exactly incorporate the time of capture into the data analysis. This gives us more power to mimic nature in the sense of how tigers actually get 'trapped' in cameras, and how their movement, behavior, and space-use relate to time. This is a significant advance," Karanth said.

The scientists illustrated this model by analysing spatial and temporal patterns evident in the camera-trap detections of tigers living in and around Nagarahole Tiger Reserve in Karnataka.

The study is published in the current issue of PLOS ONE journal.

--IANS

sgh/rn