June 27th, 2006
what do you see?
You’re wandering along an overgrown trail, constantly scanning the vegetation for moths, butterflies, other insects and spiders. An odd swollen knot on the branch of a small tree catches your eye. It’s a little lighter than the rest of the bark — sort of mottled, probably with the same lichen that’s growing in patches on the tree trunk. But there’s something about the knot that doesn’t seem quite right. You step closer to check it out and realize that you’ve been fooled by a trompe l’oeil artist. So, what *is* that thing on the branch?
The Gray Treefrog (Hyla versicolor), is a small amphibian that likes to find a quiet place to hang out during the day. Often, it chooses to perch on a leaf or tree branch, its skin colour changing through shades of green to gray in order to blend with its surroundings. The frog on the left is shown resting on a Common Milkweed plant, its skin approximating the shade of the leaves (click on image to see a larger view). I frequently find these frogs in a shaded spot among milkweed leaves — a preferred perch on a hot, sunny afternoon. When resting on tree bark or even stone, these frogs assume a mottled gray appearance such as the example below (click on image for larger view). This is the same frog that appears in the photo at the top of this post. With its rough, slightly warted skin, many mistakenly refer to these frogs as “tree toads”, but they are, in fact, frogs and not toads.
Many people have their first Gray Treefrog encounter when they find one clinging to the outside wall of their house near a porch lamp after dark. The frog has staked out a good spot where it can take advantage of easy prey — the night-flying moths and other insects attracted by the porch light. For the past two summers, I’ve occasionally spent time photographing moths around our porch lamp in late evening. More than once, I’ve had a Treefrog hop out of a nearby bush to land on my shoulder, or even on my head. It seems that I provide an excellent perch from which to launch Treefrogs at the tasty moths that I’m photographing. As you can see in the photo of the frog metamorph (below — click on thumbnail to see larger view), these frogs have toepads which they use to cling to surfaces. Their clinging ability is so good that we often find these frogs wandering about on our living room window on summer nights as they hunt for moths that are attracted by the indoor light.
Gray Treefrogs lay their eggs in water, usually in ponds surrounded by trees. The young develop into tadpoles, and then eventually leave the water. The photo on the left (click for larger view) is of a Treefrog metamorph which I found clinging to a Buttonbush next to a beaver pond. While looking very froglike, it still has a small tail.
Treefrogs are quite vocal, especially in the evenings. However, they may also be heard in forests during daylight, their calls often being mistaken for birds as they have a short, bird-like, chattering trill. I should have made some recordings to post here today, but didn’t think of it. If you’re interested in hearing their call, visit this page on the Animal Diversity website and listen to the .wav file. Keep in mind that this call can be quite loud and is often heard in forests during the spring and summer. Most years, we have at least a couple of Treefrogs hanging about in the cedars outside of our windows and they can become quite chatty, especially in the evening.
Tags: Gray Treefrog, Hyla versicolor
June 27th, 2006 at 2:05 pm
Gray treefrogs are our “house frog”. I’m not sure if we have the diploid or tetraploid, but we have a *lot* of them snoozing in the dogwoods and crape myrtles. I sometimes wonder how they manage after a month of drought, but sure enough there were dozens calling this weekend during the rains.
I love them. They’re such little dolls. Have you noticed how they hunker down and cringe if you approach them?
June 27th, 2006 at 2:32 pm
Wayne – Yes, I’ve noticed the “hunker down and cringe” thing — as if they could get any smaller than they already are! (o:
I almost posted another photo along with the above — of the same frog as seen from slightly below. I find their ability to meld themselves into such a compact and almost seamless form rather fascinating. I once had a treefrog fall from a tree and get tangled in my hair while we were hiking along a trail — perhaps it was snoozing as it was such a warm day. It felt like being hit with a giant gumdrop and it just stayed in its blob shape while I examined it. Funny little creatures! Here’s that photo that I mentioned (as per usual – click on it to see a larger view).
June 27th, 2006 at 3:00 pm
What great camouflage. He blends in so well on the branch that he is barely noticeable. I don’t know what it is about frogs, maybe because it’s one of the first little creatures I ever found in the woods when I was young, but I think they are heart-melting adorable little things. Although, I’m not sure how I would feel if one got tangled in my hair!
June 27th, 2006 at 3:42 pm
I’ve never seen one, but I hear them…great photos.
June 27th, 2006 at 4:30 pm
RA – Some of my own “first encounters” with woodland fauna were with frogs, toads and turtles. In many ways, these small creatures are the ambassadors of nature and very deserving of all of the habitat protection we can provide.
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Jimmy – Try looking around on Milkweed leaves, especially in the general vicinity of streams, or forest edges. Also, do check small trees or bushes in areas around your house where there are lights in evening. We usually have at least one “resident treefrog” living in a cedar about 4 feet from the porch light. Sometimes I catch it resting in the shade on the wooden porch railing on hot afternoons.
June 27th, 2006 at 11:05 pm
The first time I saw one of these it was dead grey, on a grey concrete basement floor. What a surprise to discover that it was a living frog–amazing camouflage. Lovely photos!
June 28th, 2006 at 12:03 pm
Pamela – Last year, I found a treefrog sitting on a piece of granite on my porch (and yes, we have rocks all over the place around here). It was so well matched to the colour and the mottling was quite well matched to mimic the section between a darker and lighter parts of the rock. Here’s a shot of it. This camouflage behaviour really warrants another post, and perhaps I’ll put something up later today.
June 28th, 2006 at 11:04 pm
Thanks for the info and great pics! One of these turned up in my yard the other evening after a day of heavy rain – calling like mad from my little pond. Somehow, it never occured to me that we have treefrogs around here – so I thought he might’ve been a leopard frog. Anyway, he’s continued to call the last few nights and I’ve managed to find him each night calling from the serviceberry tree beside the pond. The first night I found him he was a dark brown with black markings, but last night night he was a very light beige, almost gray color. I wonder if the color change has anything to do with air temperature as well as camouflage?
June 29th, 2006 at 1:27 am
Laura — Earlier today, I was looking around for some information on the colour change abilities of the Gray Treefrog. I may post a follow up on the subject, but to answer your question, I found this page that states that, “Color change is stimulated in a frog by temperature change and cues acting upon the nervous and visual systems.”
So, yes, it would appear that air temperature must play a part in triggering colour change. Thanks for posting about your experience with these frogs!
June 29th, 2006 at 1:54 am
Thanks for the link – I’d been searching myself for some natural history info about them. Wish I was able to find this little guy during the day to take a pic!
July 22nd, 2006 at 4:44 pm
Thanks for the photo! We found dozens of baby grey tree frogs this morning on a patch of milkweed near our driveway. They’re SO cute (and FAST)! Most were snoozing when we came up, but if you get anywhere near them, BLINK open the eyes and away they go. :-)
July 22nd, 2006 at 7:56 pm
Hello Sue – That’s neat that you found so many tree frogs – and on milkweed. That’s one of the most reliable places I know of to search for your tree frogs. They do seem to like to snooze on those leaves during the daytime.
August 14th, 2006 at 12:45 pm
[…] At the end of June, I wrote a piece about the Gray Tree frogs that are frequent evening visitors around our house. They’ve been quite conspicuous in recent weeks. During the hot, dry weather that we’ve had since returning home from Nova Scotia, there’s a frog that has taken to sitting in the Wild Cucumber vines that cloak the screens of our sun porch. Normally fairly quiet, the frog breaks into rapturous chattering trills at the slightest rainshower and keeps at it until the cloudburst ends. […]
October 1st, 2006 at 5:17 pm
Hi, great info and photos here. Yesterday, my husband and I discovered that a gray tree frog is sitting on a hanging plant in our greenhouse. Perhaps it was sitting on the plant as we brought it in a week ago. Anyway, I don’t know if we should leave it there. I can’t imagine feeding it, but there will be lots of aphids, white-flies, slugs and crickets in the greenhouse. My concern is that the treefrog may not be able to get out of the hanging pot. Do you know how far they can jump? Because if it can jump far, there is a planting bed about 3 feet below it and lots of other plants on the ground about 6 feet below. The temperature will vary in there during the day between the seventies and the thirties. If you have time to give your point of view, I would appreciate it. I have been looking all over the web, but cannot find the answer. Do you know if they NEED to hibernate?
October 3rd, 2006 at 3:51 pm
elaine – Treefrogs can jump very far and they’re also good at climbing up and down plant hangers, etc… so I don’t think I’d be too worried about the frog. Also, they have a pretty good tolerance for temperature change, so again, I wouldn’t worry a lot. The biggest danger for them is when they get into someplace where they can’t get access to water if they can’t leave again soon. I’ve found a couple of them dried up on my back porch after they sneaked in and then couldn’t find their way back outdoors. While on this trip here on the west coast, I also found one dried up on the carpet in the corner at a little inn where the frogs could come in from outdoors and sometimes didn’t leave the rooms after — which is too bad. — bev
October 31st, 2006 at 8:28 am
Hi! very fine picture & location
December 6th, 2006 at 9:16 pm
i see a frog
December 13th, 2006 at 4:59 am
if i looking for frog
him name is hopkin green frog
i lost my frog
love, terry
ps. i’ll find my frog
who took my frog
December 14th, 2006 at 3:56 am
You can tell it’s a frog!