"It's devastating. I've been following them every day for the last year," said Dedan Ngatia, a wild dog researcher in Kenya's central Laikipia region. "They're all dead."

Months of invasions by sometimes armed semi-nomadic herders, and tens of thousands of their livestock, have had a disastrous effect on the wildlife of a region heralded as a conservation success story.

The large-scale walk-ons, driven by drought and politics, have begun to abate, thanks to some rain and the completion of last month's local elections.

Now conservationists are beginning to count the cost.

African wild dogs, elephants, buffalo, lions, giraffes, zebra and antelope were shot and starved, or caught a disease. Or they were forced out of their usual habitats.

Canine distemper, a virus most likely caught from the pastoralists' attendant mongrels, has wiped out scores of endangered wild dogs, including all seven packs studied by Ngatia, an ecologist at Laikipia's Mpala Research Centre.