We (Lalu and I) saw an abnormal coat colour pattern in three kids of Himalayan tahr (hereafter tahr), which is the main wild prey of snow leopard in the Mt. Everest region, during a tahr population survey from early October 2021 to the end of that month in Sagarmatha (Mt. Everest) National Park, Nepal. We never saw before such distinctive coat pattern amongst tahr for our 17 years of regular monitoring on them in that region and elsewhere in Nepal.
Those tahr kids showed the normal dark tan and greyish colour of guard hair in front of their chest to facial surface, with an unusual creamy colour on their flanks (behind their shoulders to the tip of tail, see photo). Upon detecting these tahr kids, I photographed them for an evidence, despite it was foggy and close to dusk. I waited for clear weather, but soon they moved out of sight. We believed that the tahr photograph was not exposed by light reflection. This was mainly because we watched these tahrs at a distance of about 20-metres, above our observation point.
After this, I showed photographs of those tahrs and discussed with Mr. Bhumi Raj Upadhyay (Chief Warden) and other staff, including local people of Mt. Everest region. None of them had ever seen a comparable look of tahr in their lifetime.
I talked it out with Prof. Dr. Sandro Lovari (World leading veteran scientist on ungulates, who has been involved since 1990s on monitoring of tahr in the region) and Dr. Rodney Jackson (World leading snow leopard veteran scientist) and they suspected the possibility of mange. However, Prof. Lovari also discussed it with his colleague Prof. Dr. Luca Rossi (Veterinary Doctor, Univ. of Turin, who lived for three months in Namche some 15 years ago). Prof. L. Rossi excluded the option of mange on those tahrs, this was because he did not detect any scar or mange sign around their mouths and, fortunately, he recognised that those tahrs were healthy. He was not aware of any disease showing the same phenology pattern.
Prof. Lovari added that they looked like having no “guard hair” on their flanks, but only the under-wool: if so, a very strange thing for which there is no easy explanation, but for a genetic mutation. Having no “guard hair” on flanks means that rain; snow and dampness will not slide away, but will be absorbed by the under-wool, thus determining a great loss of body heat in winter, which might cause pneumonia or some other lethal condition. In sum, if it is a mutation, it should not be favoured by natural selection. I have also discussed with Dr. George Schaller (world’s leading wildlife biologist) and he suggested that those tahrs cured themselves, but required further investigation.
In fact, long-term observations would be worth doing, to monitor whether this unusual coat pattern will disappear, or it will spread, in the Mt Everest tahr population.
(Mr. Kamal Thapa is a Ph. D. student at the Institute of Forestry, Kathmandu, Nepal and is studying the behavioural ecology of mountain ungulates (bharal and Himalayan tahr) in response to predator presence. Mountain Spirit, Nepal, granted funding to undertake this study)
