Daytime bat

For some reason, I don’t know why, I managed to remain completely clueless about the existence of Chorus Frogs (Pseudacris triseriata) until a couple of years ago, and I only actually figured out what they sound like last night. This might be excused if I had no knowledge of any of the frogs or their calls, but I grew up beside a swamp; Spring Peepers, American Toads, Wood Frogs and Gray Treefrogs were all a much-anticipated part of spring. I would fall asleep at night with my window cracked open, listening to the (sometimes very loud) choir from the swamp. And yet, for some inexplicable reason, I never picked up on Chorus Frogs. It’s not even like they lack a distinct voice; when I listened to the recordings last night, I surprised myself in saying “I know that! I could swear I grew up hearing that in our swamp.”

So when I heard some this afternoon, calling from some wetland over in the neighbour’s woods, I decided to grab my camera and go check it out. It was a gorgeous day and I was looking for an excuse not to go back inside; maybe, if I was lucky, I could spot one. I made the mistake of letting Raven tag along, however. She was already outside, and though it did cross my mind that she might be a little disruptive, I thought I could just have her sit-stay by the water while I poked around. I’d forgotten how much fun she has in water, and she hasn’t really seen much water since last fall. So when we got there, it was just too much. She tried her best, she really did; she sat-stayed for as long as her quivering muscles would let her. And then she couldn’t hold herself back any longer, and leapt into the water, tuning out all attempts by me to call her back (which, really, is rather ineffectual unless you’ve got one of those remote-controlled collars on them that’ll vibrate when you press a button. Otherwise, what do they care if you yell?).

So the frogs didn’t happen. I could hear them, but I had trouble getting close enough to any to even have a chance of seeing one, since inevitably Raven would bound through just as I thought I might be getting closeish to one. But I found something just as good, or even better.

I didn’t notice it at first, until it left the tree it had been hanging on on one of Raven’s drive-bys. It was a bat. It swooped down toward the water’s surface, skimming along and touching down once or twice, scooping insects from its surface (presumably; possibly it might have been drinking, although these shots suggest a different posture for that). Then it would return to the tree trunk to eat, hanging upside-down.

I was absolutely fascinated, and this made the entire trek worthwhile. I’m not sure how long I stood there, watching it, but probably fifteen or twenty minutes. It moved to the far side of the swamp for a little bit, and I watched it fly back and forth over the water over there, while a Hairy Woodpecker worked a tree and a couple of robins moved through the branches above.

(Naturally, I didn’t have my telephoto lens, but at least I had my mid-sized lens, my 100mm, and not my short landscape lens, the 55mm. These are all 100% crops, which, in combination with the moving target, accounts for the low image quality.)

I was standing at the northeast side of the water, so as it swooped back and forth the sun would shine through its thin wing membrane, illuminating it and highlighting the bone structure. That’s not something you get to see too often!

I was a little surprised to see a bat out in plain daylight, and in the sun, no less, not even the deep shade of the forest (or what might pass for deep shade in the leafless deciduous woods). Googling it, though, it seems this isn’t an altogether unusual occurrence. Most of our bats hibernate over the winter. In the spring, as the temperatures are just starting to rise, the nights can often still be quite cool or even freezing, even while the days are fairly warm. Early-risers may take advantage of these warmer daytime temperatures to do some foraging, choosing to sleep at night instead, at least until the nights start to warm up, too. Not only are there a lot more insects out flying during the day (if the temperature’s really cold, there might not be any insects at all at night), but it’s a lot easier on the bat, too. Once the nights are warm enough they’ll return to their nocturnal habits.

I couldn’t tell you what species it was. According to the Atlas of the Mammals of Ontario, there are 8 species of bat in the province. I know Red Bat (Lasiurus borealis), Silver-haired Bat (Lasionycteris noctivagans) and Hoary Bat (Lasiurus cinereus), but the rest of Ontario’s bats all sort of blend in together – especially when you’re seeing them from a slight distance, while they’re on the wing. The remaining possibilities are Eastern Small-footed Bat (Myotis leibii), Little Brown Bat (Myotis lucifuga), Northern Long-eared Bat (aka Northern Myotis; Myotis septentrionalis), Eastern Pipistrelle (Pipistrellus subflavus), and Big Brown Bat (Eptesicus fuscus). From what I can tell, ID between these species depends primarily on structural details of the ears and head that can’t be seen in flight or from a distance (unless you have a really good camera).

The two brown bats are the most common, judging from the mammal atlas, and the Big Brown in particular. I read through all of the descriptions in my Peterson mammal guide, though, just in case it offered any clues there. It was the habitat and habits I was most interested in. The habits of Eastern Small-footed Bat and Northern Myotis didn’t seem to match, but the other three had possible similarities:

For Little Brown, it comments: “Forests and rural areas, usually near streams and lakes” and “Emerges at dusk or later, usually flying to water to forage and drink. … Feeds mainly on emerging aquatic insects”.

For Eastern Pipistrelle: “Woodland or mixed farmland” and “Feeds on tiny flies and beetles, hunting over water or at forest edge”.

And for Big Brown: “Forests, farms, cities” and “Feeds on beetles and other insects, hunting over fields or streams … Will awake and become active in response to temperature change – a bat seen out and about in midwinter is almost sure to be this species.”

It’s the note about Little Brown feeding on emerging aquatic insects that causes me to lean toward that species as the most likely candidate, although Big Brown seems like a pretty good possibility as well. Being completely subjective about it, the shape and relative size of the head in the first photo, where it’s hanging on the tree, seem a better match for the Little Brown in my guide. But it’s probably one of those things that has to be left without a definitive ID. Pretty cool, regardless!