September 9th, 2006
night stalker
Back on August 14, I wrote about the Gray Treefrogs (Hyla versicolor) that wander about on our windows at night. The previous evening, I had missed an opportunity to photograph a frog on the living room window. Last night, I got a second chance for a few shots after a thunderstorm earlier in the evening. At around 9 p.m., a tree frog showed up to stalk moths on the wet glass. In the above photo, the frog is climbing upwards toward a moth that it had spotted at the top of the window (click on images for larger view). The bright yellow on the inner thighs is a diagnostic marking for this species.
Below, I’ve posted an enlarged shot of one hind foot as I thought it might be of interest to those who haven’t watched a treefrog moving about on a windowpane. They really do have fascinating feet. The toepads grip onto all types of surfaces, including wet glass. I did a bit of searching for info on treefrog feet this morning and came up with something new that I hadn’t seen before. Here’s a link to an article in Science News Online from June 10, 2006, that describes how tree frogs are able to stick to both dry and wet surfaces. When moving over dry surfaces, the toes secrete a slightly sticky mucus film that helps to provide some wet adhesion. However, it seems that when moving over a wet or slippery surfaces, such as the wet glass in my photos, the structure of the toe pads — microscopic bumps on the surface of the pads, with mucus channels between — moves fluid so that the bumps will make the best contact with surface. Read more at the above website.
Tags: Hyla versicolor, Gray Treefrog
September 9th, 2006 at 1:49 pm
Bev – the gray treefrogs are my very favorites, although I can’t tell the difference between the diploid and tetraploid species. I’ve noticed how ably they can cling to my hand and then transfer without difficulty to a completely different surface like a tree branch, but had no idea of the mechanism.
I think many people miss that bright yellow coloration beneath. I failed to post last June a similar shot-below that showed it distinctly but those photographs capture it perfectly.
There’s a lot of yearly encounters that always cause me to think “welcome back”. Hummingbirds, daisy fleabanes, krigia dandelions, the snapping turtle. But I think it’s the gray treefrogs that I’ve noticed more than anything, and have a particular soft spot for.
September 9th, 2006 at 2:08 pm
Uh-oh – my comment may have gotten eaten. Well, gray treefrogs are my favorites here. The yellow coloration is something most people miss. I love the bottom picture and wasn’t aware of the mechanism that allows a frog to cling to my hand and then transfer smoothly to a completely different surface like a tree branch.
I also love the way they cringe when they detect that you’ve spotted them.
September 9th, 2006 at 2:44 pm
Wayne – There we go — I removed the extra posts but left this one as it include the bit about the way the little tree frogs cringe. I’ve noticed that as well, especially with the very little ones. They just make themselves squish into the tiniest little blob. (-:
Tree frogs have been very much in evidence around here this summer…. probably more than usual. Lots of them around the house and on the milkweed in the yard. There are a couple that trill outside the bedroom window at almost any time of day or night. They very much like the wild cucumber vines that run rampant over the sun porch.
September 9th, 2006 at 3:01 pm
Bev – I should be more patient!
This is the first year I’ve noticed something new about our tree frogs. We built a number of ornamental, fairly large (3-8 kiloliter :-) ) ponds and of course immediately had several species of frogs appear, including the gray treefrogs. Build it and they will come.
But *this* year I didn’t just hear them close to the pond, I heard them *everywhere*. Way out in the trees, in dry areas, and extending down to the creek. It’s too early to tell if I managed to produce some kind of wildlife connector or nucleus for babies or what.
I always listen for the gray treefrogs as an indicator of upcoming rainstorms. They always seem to know, and are perfectly willing to share their perceptions.
The local significance of this little story won’t ring a bell with you, but in the course of my job tutoring student athletes I was invited along with many of my students and fellow tutors and counselors to a little fete at Vince Dooley’s house a few years ago. Vince Dooley is kind of a legendary football coach here, but none of that is very important to the story.
Dooley, who is himself a veteran fan of horticulture and has quite a fabulous garden, was giving a little speech and there was this raucus little voice trying to outdo him, and he said “Does anyone know what that is?” and I yelled out “Cope’s Gray Treefrog”. Everyone was VERY impressed.
September 9th, 2006 at 3:15 pm
Wayne – Ha! That’s a great story! On occasion, tree frogs can break into the most incredibly loud chirping trills. We’ve got a few that are just like that around the house — especially the ones that hang out in the wild cucumber vines. We often hear them throughout the forests here and in the many places where we hike. I would think that the movement of tree frogs into other areas of your property must reflect the increasing tree frog population, and maybe the age of the population as well. I usually find small frogs close to ponds or along ditches, but often find adult frogs on trees at quite some distance from water.
September 9th, 2006 at 3:47 pm
Aha! Now I see what made your visitor’s scream in fright – that top pic is a little eery!
The tree frog that had been calling for weeks near our pond finally got quiet – I hope he found a mate or a bigger pond, but I’ve missed his nightly calls.
September 9th, 2006 at 10:06 pm
That would be a startling sight in the window on a rainy night. How lucky you are! Fantastic shot of the foot. And the yellow–I sure didn’t know about it.
September 10th, 2006 at 1:18 am
From a person far more familiar with human anatomy, the climbing frog is amazingly similar, down to the five digits at the end of the limbs. Spiderman move over, frog man is it. Everytime I log on to your site, I learn something interesting. I am looking at my local environment with new eyes.
September 10th, 2006 at 9:36 am
Beautiful artistic photos! I heard the tree frogs all summer but have yet to see one this year.
September 10th, 2006 at 1:24 pm
Pamela – Yes, sometimes the tree frogs do catch us a bit offguard late at night when they suddenly plunk onto a window and are stretched across the glass. As mentioned in the earlier story, a tree frog certainly gave our Dutch friends quite a scare one night during their visit! (-:
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Ruth – While watching the tree frogs moving about on the glass, I often think of how alike they seem to the way that rock climbers move about over a surface. Glad you are finding plenty to interest you on my blog and that, in some way, it may be changing how you are looking at nature. I know that my own way of seeing is constantly changing as my awareness of nature grows.
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OW – Thanks! I was hearing more frogs than I was seeing, but now I’m finding the little ones all over the place, and the large ones have been pretty active on the windows around the house for the past month or so. In the past, I’ve noticed that the tree frogs become more noticeable around this time of the year as they spend part of the day basking on milkweed leaves. I guess the coolness of the air temperature causes them to seek good basking spots, especially in the case of the juvenile frogs.