The Nature of the Beast (according to Susan McCarthy)

I'm still in the dark. Fortunately, I'm nocturnal.

Update on the SF Zoo's tool-flourishing aye-ayes:

I recently got a short tour of the normally-closed nocturnal house. This now houses an elderly mouse lemur and a thriving aye-aye family. Sabrina and Warlock produced a son, Dobby, who looks just as eccentric as his elders. He is only the 2nd second-generation aye-aye born in the US, so the Zoo is extremely proud of him. Asked how they accounted for this success, our guide said that it seems aye-ayes like to mate high in the trees, and the nocturnal house has a high ceiling which can be utilized for this romantic purpose.

Several months ago, to general surprise, Sabrina and Warlock produced another baby. It had been expected that it might take the couple five years to have their next child, not just one year. (Ah, high ceilings...) This daughter is allegedly still unnamed. (I find this unlikely. I suspect she has a name but it is being kept secret for one or more of the usual bizarre zoo rationales for withholding such non-Nature Facts. Or they are just embarrassed that they named her Morticia or Grimalkin or whatever.)

I asked about the wrench. “Oh yes,” said the guide. “We give them wrenches for their teeth.” It seems that aye-ayes have ever-growing teeth, like rodents, and need hard objects to gnaw on so their teeth don't overgrow. For this purpose they are given bamboo and hard wood. And wrenches.

The guide, who does not appear to have been at the Zoo very long, seemed to find this perfectly mundane, and offered no explanation for how wrenches came to be the dental device of choice.

(“Sure, we give the aye-ayes wrenches for teething. Just like we give the otters eggbeaters for grooming, and we give the pelicans assault rifles for nest-building. It's environmental enrichment.”)

Until I get a different suggestion, I am sticking with the hypothesis that this practice originated in an aye-aye act of pilferage.

What Shall I Do with These Opposable Thumbs?

A few years ago, Terri Nelson and I went to the San Francisco Zoo, and came upon the Nocturnal Gallery. This is closed now, but it was a little building with glass-fronted cages with small primates. It was dark inside, with double doors so people entering  wouldn't let in daylight. There were dim red lights. If you waited long enough, your eyes would adjust and you could dimly see small nocturnal animals hustling along tree branches, sorting leaf litter, and grooming each other. Most people didn't take the time, and went out again. We were alone with tiny primates.

Terri and I were spellbound. Bushbabies! Then we saw the mouse lemurs, infinitesimal primates you could hold in the palm of your hand, if it were allowed. We felt compelled to peer at them in case there was a still smaller baby mouse lemur clinging to its mother.

Then we spotted the aye-ayes, and were stunned with delight. Aye-ayes are rare and endangered, five and a half pounds of nocturnal weirdness from Madagascar. Few zoos have them. Aye-ayes eat grubs that burrow in decayed wood, so they fill the ecological niche of a woodpecker. (A big woodpecker. Given their size and rarity, let's say an Ivory-billed Woodpecker.) They have opposable thumbs and skinny witchy fingers, especially their middle fingers, which are ridiculously long, Edward Scissorhands long. In the Malagasy night, they tap on trees, listening with big bat ears for hollow sounds, and for a grub squirming. Then they bite a hole in the wood and pull the nutritious and no doubt tasty grub out with that long middle finger.*

In the dimness of the nocturnal house we could see the aye-ayes parading along horizontal branches, making daring leaps from one branch to branch, and pausing so we could drink in the spectacle of their crazy staring eyes, their disheveled fur, and those bizarre hands. They popped in and out of a wooden nestbox.

We had been looking silently for a long time, bewitched, when we saw a quick flash in the enclosure. It was a red bar of light that appeared for a second and then was gone. It came again. “Did you see that?” “Yes -- what was it?” We stared. Nothing. Then, again, from a different spot. We couldn't figure it out. Were there lights in the enclosure with the aye-ayes? Some kind of motion detectors? It flashed from a different spot. Then, gone.

It flashed twice, in the same spot. We peered and suddenly saw an aye-aye sitting on a branch. Facing us. Brandishing a large wrench.

“Do you see that?!” one of us asked in disbelief, and the other one hissed, “Yes.”

When the wrench was tilted toward a red light, it reflected a red bar of light from the handle. The flashes from different places must have come as the aye-aye paraded around with the wrench. The aye-aye manipulated the wrench thoughtfully, then jumped up and disappeared into the nestbox. When it came out, it had no wrench.

We tried to figure it out. When one of the cages was being repaired, someone had left a wrench lying around. The aye-ayes had stolen it. They were hiding it in the nestbox. Clearly they planned a break-out. “They plan to use it to unbolt something and escape,” I hazarded. Terri showed a better understanding of basic primate thinking. “They plan to hit the zookeeper on the head with it and escape,” she said.

*There are no woodpeckers in Madagascar. Feel free to use this remark the next time conversation falters.