One of the down sides of studying juvenile ring-tailed lemurs is that not too many of them stick around for long. This populations has an average mortality rate of about 50% -- half of the kids from any given year will die, whether from infection, some congenital defect, or predation. This year has been especially good for the predators since now over 60% of this year's kids have disappeared. We're never really quite sure what happens to the kids. They could be picked off by the Madagascar Harrier Hawk, for example. The harrier hawk is a really impressive raptor. When I hear hawk, I think of something like a red-tailed hawk or maybe a Swainson's hawk. Both of these aren't so big. The Madagascar harrier though is about 70 centimeters, making it pretty huge by hawk standards. The lemurs are pretty scared of them, and just hearing the call of a distant soaring harrier is enough to drive them down low from the trees and contact call as if checking to make sure everyone is around. A close harrier will make the lemurs scream an alarm call and dive down out of the trees. This is especially fun if you're standing directly under them and you have a dozen or more screaming lemurs jumping down at your face.
Ring-tailed lemurs here are also eaten by dogs and feral cats. The lemurs hate, hate, hate dogs. Dogs barking freak them out. Cats on the other hand only inspire low grunting and maybe moving a little higher in the trees. Considering how many lemurs are probably eaten by cats, and what C & I saw in the forest, maybe they need to get on top of the cat alarm calling.
We were watching Green group in the eastern section of the forest (our study groups are all collared and named accordingly. I'm studying Green, Red, Blue Orange, Yellow, Teal, and Purple). Green was on the ground licking dead wood (probably to eat termite soil), when I saw another group about 20 meters away. I could see a collared male, but couldn't read his number and didn't see collars on anyone else. There are quite a few uncollared lemur groups around, and since males transfer between groups I asked C to go check it out and see who it was. While she was watching the new group I finished up my observation session and joined her up the trail. We saw a subadult sitting on the trail and then spotted a juvenile coming down a large tree about 10-15 meters away. C & I were looking around trying to see what lemurs were around when we heard shrieking and screaming. At first I thought it was just the kid getting beat on by another lemur, but when I looked down I saw that it was the kid all-right, but it was getting killed by a cat! The cat had pinned the kid down by the neck/back of the head and the lemur thrashed for a couple of seconds and then was still. The cat looked up at me with a 'back off-- this is my lemur' angry kitty face and then took off, with the dead lemur in its mouth like a kitten, down the trail and then disappeared off of the trail. C and I tried to follow her, but couldn't find the cat or her newly acquired prize.
Here's what I found a little disturbing. There were no alarm calls until about 30-40 seconds after the kid was dead and gone. No warning, no shrieks from the adults who jumped away as the kid was getting munched by the cat. Maybe its that the cats are too stealthy for the lemurs (lemurs are dumb. duh-umb), or that the adults were trying to stay hidden as long as possible until they were at an appropriately safe spot to alarm call or what, but the lemurs aren't so good with the cats.
I hope that the cats can continue to eat the other groups that I'm not studying so that I can keep the few lemurs I have left. We'll see about that one though.
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