Wild Cats and Climate Change

Written by John Seidensticker, this article is reprinted from Wild Felid Monitor, the newsletter of the Wild Felid Research and Management Association (WFA) www.wildfelid.org 

The 1,300 square km lowland, secondary, tropical forest in Way Kambas National Park on Sumatra's southeast coast normally receives 286 mm of rain per month. But during the 1997 El Nino, the park received less than 10% of normal. Neil Franklin (2002) observed seawater intruding in the waterways 16 km inland from the coast; fires burned over 55% of the park; poaching pressure increased; and the total estimated tiger density was 4.6/100 sq km in 1997, 2.6 in 1998, 1.1 in 1999 and 2.6 in 2000. While some tigers died in the fires, the results of the fires on prey populations and direct mortality from poaching could not be separated.

The park is a habitat island surrounded by human settlement and cultivation; options for connecting it through corridors with other protected areas are no longer available. For now, Way Kambas continues to limp along. A new El Nino event will again threaten, or even overwhelm, the small population of Sumatran tiger, rhino, elephant, clouded leopard, flat-head cat, golden cat, and fishing cat and the multitude of other plants and animals that live in this tiny vestige of what was once the great lowland rainforest of Sumatra. Way Kambas is set up for a catastrophic event, and there isn't much anyone can do about it.

Unlike Way Kambas, the temperate deciduous and boreal forests of the Russian Far East (RFE) are extensive. We have estimated there is 269,979 sq km in the REF-China Tiger Conservation Landscape; the largest habitat patch is 183,237 sq km. The area of land actually occupied by the remaining 500 or so Amur tigers is about 160,000 sq km.

Like Way Kambas, the region is severely threatened by wild fires that appear to peak during El Nino events, and are expected to intensify with global warming. Tatiana Loboda is modeling the "Impacts of climate and land use change on wildfire frequencies and the Amur tiger" for her Ph.D at the University of Maryland. This is one part of a major joint University of Maryland, University of Virginia, and Wildlife Conservation Society project funded by NASA.

With global warming, scientists are finding Amur tigers living further north than they have in the past. Tigers adjust their range occupancy in response to that of their primary prey - deer, especially red deer, and wild pigs. The distributions of deer and pigs and tigers is thought to be related to winter snow depth, which appears to be decreasing.

We find big cats moving north following the deer in North America; Ramona Maraj, senior carnivore biologist for the Yukon Department of Environment Yukon, tells me they are sighting cougars more often in the southern Yukon as they see increasing numbers of white-tailed and mule deer responding to climate warming in the Yukon.

We expect Canada lynx to change their range in response to warming climate. Nils Stenseth et al modeled how differential snow conditons, such as surface hardness determined by the frequencies of warm spells, influenced lynx interactions with the snowshoe hare. Variation in snow conditions are influenced by North Atlantic Oscillation (NAO)-linked periodicity. Changes in the NAO in periodicity and intensity will alter spatial, ecological and genetic structuring of the lynx population, Stenseth et al predict.

The tigers living in the 10,000 sq km Sunderbans mangrove forest wil probably not survive the expected rise in sea level with global warming. This forest is the interface where the great rivers Ganges, Brahmaputra and the Meghna join the Bay of Bengal. But the Sunderbans will also be negatively impacted by changes in glacier and snow melt in the Himalayas.

Himalayan glaciers, only exceeded by the polar ice in volume, often called the water towers of the Ganges plain, are melting as a consequence of global warming. This is of course a concern for all the people living on the Ganges plain. it is also of great concern for those interested in the conservation of snow leopards, the cat of high altitude Himalaya and central Asia.

Changes in river hydrology with reduced runoff will impact the forests and elephant grasslands found along the outer range of the Himalayas, in the Shivalik Hills, and the associated narrow strip of lowland forest in the bhabar and the terai. This is a 49,000 sq km Tiger Conservation Landscape stretching 1000 sq km, from Corbett National Park in India to Chitwan National Park in Nepal, parts of which were so artfully described by Jim Corbett.

As we have seen from these examples, depending on the species of wild cat there will always be loss of critical habitats and range fragmentations, contractions and expansion, resutling fron climate change. We have no choice but to learn to live with and work with these changes. I suspect most wild cats will not fare well, but we know so little about most wild cat species that making predictions is speculation. I do think we can confidentially predict that the domestic cat will be just fine.