J. M. Goodrich, I. V. Seryodkin, D. G. Miquelle, L. L. Kerley, H. B. Quigley & M. G. Hornocker, 2011, J. Zoology, 285: 93-98
Teeth have always fascinated me. Because they are so essential for animals’ survival and also because of how intricately they show animals’ adaptation to their ecological niche as well as their personal history. Show me your teeth and I tell you who you are. And what better examples for this are there than the canines of a predator?
A few years ago I was working on Barro Colorado Island in Panama at the same time as another team was conducting a tracking study of ocelots. To catch the ocelots, the researchers set up traps in the forest, baited with a live chicken. One female very quickly figured this out and turned “trap happy”, to the great annoyance of the ocelot researchers who would have liked to catch some other ocelots, too, and to the great delight of the rest of the scientists on the island, who got to see the release of a wild ocelot. “Oreja” was very old and all her canines were broken – the easily accessible chickens were thus a welcome addition to her diet.
I know that broken and missing teeth can decrease the feeding efficiency of animals, ultimately even leading to their death (as the ocelot researchers on BCI also found). But I did not know that missing canines are thought to create problem animals, because they start hunting domesticated animals, and that missing teeth are even a criterion that is used to identify and sometimes cull potential problem animals. In the current Journal of Zoology issue researchers from Russia and the USA put this to the test.They investigated the reproductive success of highly endangered Amur tigers with and without missing or broken canines in the wild, and they assessed the number of individuals with missing or broken canines, killed because of human-tiger conflict. Their results are sobering AND encouraging: the proportion of tigers with missing teeth was the same in the control population as among the killed conflict tigers and both groups seem to have the same number of offspring. These results are congruent with those for African tigers and thus imply that culling large felids with missing teeth to prevent conflicts with humans does nothing but kill more animals from usually threatened species and that management measures have to be more differentiated.
Between being an interesting read on an interesting subject– tiger canines – and presenting an impressive sample size from an animal that is rare and extremely difficult to study, this paper is an excellent example for the ZSL’s motto on the journals front page: living conservation!
Oreja, our trap-happy old island ocelot, with no canines left at all may have been a special case. She was caught about a dozen times and in spite of her broken canines she never attacked anyone.