The Bats of Summer
(click on a photo to enlarge)
For some reason, I never paid much attention to the little bats that use our porch ceilings for temporary roosts at night. I can’t even put a date on when they first showed up but the first sign that the bats have returned are the little bits of bat guano laying on the floor tiles in the morning. This is a sure sign that a bat has spent some time hanging from the wall or rafters above on the previous night.
Bat Guano
It was a fierce electrical storm and my desire to photograph lighting that took me out onto the front porch one night. My attempts to capture lightning were futile but as I turned around to go back inside, I noticed a group of bats clinging to the house wall. I had no idea what they were but they stayed put and I snapped off a few photos. Here’s what I got:
I soon discovered that bat references are somewhat marginal, especially photos, so I turned to our local bird listserv for help and in no time at all I had my bats identified*. The cute little row of bats above are Pallid Bats (Antrozous pallidus).
As bats go, I think the Pallid Bats are quite good-looking and they are certainly tolerant of a flash going off in their faces!
Pallid Bat (Antrozous pallidus)
Large ears enable them to hear insects walking on the ground and they often bring their catch back to their night roost for consumption. Their preferred prey are scorpions (yay!) and crickets but judging by the moth wings I find where they roost, they must like those too — not the teeny little moths that get in our homes but the large meaty silkmoths such as the Rustic Sphinx Moth, Manduca rustica which are several inches in length.
Rustic Sphinx Moth, Manduca rustica
I also discovered that ants work at night! Here they are carting off one of the discarded moth wings. Not only that, they take every last dropping of guano if we don’t sweep it away during the day.
The Clean-up Crew
Here are a few more of my favorite “group photos” of the Pallid Bats. Note in the bottom photo that the second bat from the left shows how the tail is enclosed in a membrane. Another group of bats, called “free-tailed bats,” do not have this membrane. I also wonder if these are family groups? Young are born in early June and it takes about 8 weeks for them to attain adult size. These photos were taken in mid-August.
Another “regular” under the porches is the dark-faced and glossy-haired Big Brown Bat (Eptesicus fuscus). This bat confused me no end because it didn’t look all that big (although it does look rather pudgy in the photo). There was one spot on one rafter where this bat would return to night after night. It didn’t look any different from any of the other rafters but the bat obviously preferred this particular spot.
Big Brown Bat (Eptesicus fuscus)
Big Brown Bat (Eptesicus fuscus)
The only other bat I’ve seen is probably a Southwestern Myotis (Myotis auriculus) a Mexican species found only in southeast Arizona in the U.S. but since Myotis species are difficult to identify unless in-hand, we’ll just leave it as Myotis sp.
Myotis sp. Wet from Rain
Oh, yes, the nectar bats have finally returned. They are leaving their yellow “calling cards” everywhere and draining the hummingbird feeders at night. If you missed the blog post about nectar bats from September 2009, you can read it here.
The Nectar Bats Are Back (get out the power washer)!
*Many thanks to Bill Berger & Angela McIntire, Bat Specialist, both of Arizona Game & Fish Dept.
September 9th, 2010 at 12:20 am
Great pictures! I, too, keep seeing bats around but without being able to identify them. I rarely see them at rest, just fluttering around my black lights helping themselves to ‘my’ bugs.