Don’t worry, this isn’t about the Dark Knight.  Well, maybe it is about the dark night & the bats that may come with it.  Have you ever really thought about bats??  I hadn’t.

I took a much-needed 4-day mini-vacation in Oregon last week (- I know, you’re thinking, why on earth does someone who’s not ‘working’ need a vacation?  Well, we do & I did).  My friend Elli suggested one morning that we go to the Oregon Zoo in Portland. We headed off first (of course) to the primates of the “Fragile Forest” (i.e., our relatives who are rapidly headed for extinction), but the chimps (pan troglodytes) were resting & bored & I was miffed that there was no mention of bonobos (really?!).  & no mention either of evolution, in any of the zoo’s educational displays, even though the Association of Zoos & Aquariums statement on evolution supports “the important science education role…zoos and aquariums play in their communities.”  Geez.

Nevertheless, I loved visiting this pleasant & well-maintained zoo (in contrast to my last zoo experience in San Francisco…truly an embarrassment for that otherwise dynamic & artful Bay Area City).

The big surprise for me were the bats (Rousettus aegyptiacus).  Call me ignorant, but I had never realized that the bat wings were formed from 4 of the 5 fingers of this mammal’s hands. Maybe this is common knowledge to Batman fans – I dunno.  But as I watched these amazing creatures moving along strands of rope to & from the fruit hung as food in their home-cage, I figured out that the claw on what looked like the elbow (not) of their wing was actually the thumb of their hand – & that the rest of their fingers form the structure for their wings!

No doubt you already know that all tetrapods (the group of creatures made up of amphibians, reptiles, birds, and mammals – humans too) have the same pattern of four limbs & five fingers. That’s because we land-&-air creatures are all descended from a common fish ancestor who lived about 400 million years ago. Scientists theorize that there is no inherent benefit to having five digits as opposed to four or six or three…it was just the random nature of evolution up to the point when certain fish found breathing the increasing levels of oxygen in the air more beneficial than staying in the water; they eventually had descendants who ventured onto land & eventually into the air. Five digits were good enough then, & apparently were good enough to survive natural selection since then.  Personally, I’ve no doubt there was some reason that five worked best, & I’m on the lookout for new research that supports that notion…pentameter & pentagons & pentancles & all of that…

But hey, seriously, here in North American we really depend on bats for their role as insect-eaters.  In some parts of the U.S., a disease called white nose syndrome is killing off huge bat populations, with unknown consequences for local ecologies.  The zoo visit was a good reminder of this complex living earth we all share…change or lose one creature or plant or virus (& humans are already changing multitudes of things about our planet) & who knows what that change will lead to.

So, again, (& I can say it more easily here than for the rats): bats are our friends – fellow, mammalian (or even, for some, Hollywood) creatures!  & I haven’t even talked about how they see with their ears….