If you’re a human being, that’s probably something of a surprise, since the chances are that you can’t hear them at all. We all know they use sound for echolocation, but those sounds are simply too high-frequency for most humans to hear. You might be very lucky, particularly if you’re young, and just be able to pick out their squeaks right at the edge of your perception, but even then it’s so marginal that you’re only catching a tiny part of the sound intensity bats emit. It turns out that bats are some of the loudest animals on the planet, with some species able to emit sounds up to 130db, which is just about the threshold at which sounds become painful to humans and significantly louder than the inside of a nightclub or watching a jet take off from 100M.

I find it amazing that something can be so incredibly loud, and yet seem completely silent to me. It’s weird to think of those quiet summer evening I’ve spent watching them flit about overhead being set against a deafening¹ crescendo of noise. Nature never ceases to amaze.

All of this, incidentally, came out of a piece by Ed Yong, at Not Exactly Rocket Science, about a species of bat that has evolved much quieter squeaks in order to sneak up on the moths it preys on. It’s fascinating; go read.

And if you’re interested in little-known bat trivia, did you know that they account for a quarter of all mammal species?

1. literally; at that volume, serious hearing damage is a very real possibility. [↩]

… or er something.

Suddenly I feel a lot better about myself again. I mean, I might have underestimated the diversity of an important order of mammals, but at least I can tell the difference between a cat and an orange. This guy is either stupid enough that he can’t or stupid enough to think scientists can’t. I’m not sure which would be worse.

In any case, PZ says everything that needs to be said.

I don’t know: no sooner do I start to think I might be doing OK at this taxonomy thing, than someone comes along and knocks me right back down to peg one (to mix my metaphors.)

On Monday, I was able to spot the error in Kevin Z’s WTF without even thinking about it¹ (Echinoderms are not a subset of Insecta; they’re a phylum all their own, and while I can never keep up with whether Insecta is a class or a sub-phylum this week, I do know for sure that it doesn’t contain an entire other phylum. Oh, and it’s not even like Insecta is a subset of Echinodermata; it’s part of Arthropoda)

So there I was, feeling pretty good about myself, when Carl Zimmer comes along and (amidst an entirely fascinating article) hits me with something I never expected: one quarter of all mammal species are accounted for by bats!

That’s staggering. I had no idea they were so successful or so diverse. I’d always thought of them as being slightly odd outliers on the graph of mammal survival strategies; I mean, stretching your arms out hugely and flapping around using sonar to catch insects is just so far from what you expect mammals to do that it didn’t even occur to me that a significant proportion of them might be doing it anyway.

Obviously a quarter of all species is not even remotely the same thing as a quarter of all individuals, but still — how did I not know this? I guess I just haven’t been paying attention.

1. Well, obviously not entirely without thinking about it. [↩]