The anurans of autumn

September 29, 2015 • 12:30 pm

by Greg Mayer

In a previous post here at WEIT, I’d reported on some toads and a painted turtle that I’d rescued from stair and window wells, and then released back into the wild last spring. I’d mentioned at the time that I periodically check these places, especially a deep (ca. 20 feet down) window well on the west side of the building my office is in, because it faces a pond and woods, and animals coming out of the woods regularly fall down into it. So at the beginning of the semester in early September, I took my vertebrate zoology class out during our first lab period, and we investigated the window well. There was a pretty good ‘crop’ this fall– eleven American toads (Bufo americanus), and 23 green frogs (Rana clamitans).

Bufo Kenosha 1
American toads just outside Greenquist Woods, Kenosha, Wisconsin, 17.ix.2015. There are clearly six of them, the same ones as in “Spot the toads“.

The toads fell into two size classes: medium (in picture above), about 55 mm snout-vent length, and small, about 40 mm. The green frogs were all about the same size– 35 mm. These latter were probably all a single age class, having metamorphosed from tadpoles earlier in the summer, and then hitting the building and falling in the window well as they began to disperse away from their natal pond. Bullfrogs (Rana catesbeiana) are also common in the pond, but we’ve never found them in the window well– they must have different dispersal behavior.

Chrsi Noto Bufo release
Chris Noto helps to release American toads in Greenquist Woods, 17.ix.2015.

Frogs and toads are collectively known as anurans— it means “not having a tail”– and adult frogs and toads do, of course, lack tails. The anurans we rescued from the window well had been there varying lengths of time, but most were in at least decent shape, though some were thin and dehydrated. We kept them in the lab for a couple of weeks, feeding them and rehydrating them. We then released them on two warm days just as autumn was about to begin. My colleague Chris Noto was teaching a lab on a floor looking out over the woods, and he saw me encumbered with toads as I attempted to take their pictures and carry them back out to the woods. He came down and helped with the pictures and the release (which were featured in two “Spot the __” posts, on frogs and toads).

Bufo Kenosha 3 20150917_162944
Small American toad, about to be released into Greenquist Woods, 17.ix.2015.

The green frogs were released a few days later.

Rana Kenosha 1 20150920_153340
Green frogs anxiously await their transfer to the pond, 20.ix.2015.
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One last picture.
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Well, maybe just one more.
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And then it’s time to re-enter the pond.
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Green frogs queue up to enter Greenquist Pond, 20.ix.2015.

[JAC: a video of the release. I have to commend Greg for both taking the time to rescue these frogs and also calling them to our attention. Frogs are not only underappreciated animals, but are harbingers of human damage to the environment, climatic and otherwise. And I’ve always said that if frogs hadn’t evolved, we simply wouldn’t be able to imagine them!]

There are at least a dozen or more different sorts of anurans around the world that are worthy of their own vernacular name, but because only two sorts occur in England, we are stuck with calling them all either “frog” or “toad” in English. The American toad and the green frog do, however, correspond to the two sorts found in England (what are sometimes called the “true toads” and the “true frogs”, respectively).

Anurans are amphibians, and like most amphibians, have a complex life cycle. The word “amphibian” alludes to this– it means “both lives”, because a typical amphibian lives both on the land and in the water. Reptiles and their descendants (the amniotes, including birds and mammals), do not have this dual life cycle. One of the former candidates for the title of “first reptile” was the 270 million year old Seymouria, which has reptile-like features; but when it was found that its close relatives had aquatic larvae with gills, it was clear they were not reptiles, but rather led the “both lives” of an amphibian.

“Both lives” does not seem to adequately summarize the life of a typical amphibian, such as the American toad. They begin life as eggs in water, hatch out as tailed, gilled, tadpoles, that then swim about, eventually losing their tails and gills and sprouting legs to transform into toadlets, which then move onto land. After sexually maturing, they return to the pond each spring, to resume an amphibious existence, there to mate and reproduce. The adults then leave the pond for the summer to live wholly on land, while their eggs begin the complex cycling again. To paraphrase The Who, “Amphibians? They’re bleeding Quadrophibians.”

21 thoughts on “The anurans of autumn

  1. My son (11) has a window well outside the window in his bedroom. He is constantly rescuing critters that have fallen into it. The record so far is 11 toads (in one rescue – following a rain storm). It’s just a standard sized window well.

  2. When we live by the water as I do, we should see lots of frogs and toads. I see more this year but it has also been a wet year. Hopefully it is a good sign and these critters are making a come back.

  3. I took q picture of a giant toad this summer. The toad was sitting in my car port & was unhappy to be photographed. I came back to look at him again later to see he had moved. Using my toad sense, I figured he’d waddled off to the garden and that’s where I found him to photograph again. I could almost hear him swearing at me.

  4. The English “frog” and “toad” are rather limiting. The French name for tree frogs (Hylidae, in North America) is “rainette”, and I think that it’s one that we should pirate – evocative in the way that it suggests the sort of nights when you usually hear tree frogs calling.

  5. Thanks for this lovely article, and kudos to Greg for his thoughtful rescue service (and for raising his colleagues’ awareness of it). We have a little pond (20x8ft) which every spring becomes exuberant with anurans: this year about 50 frogs and 20 toads (the newts lie around all year). As an exemplar of rebirth and fecundity it can’t be beaten!

  6. Small world. I came across a toad just today while mowing the lawn. I put it into a window well for safe keeping until I could finish with the lawn. On my day off tomorrow I plan to take pictures of it and release it.

    1. We moved into our current house about six years ago and there were toads all over the place. If I have to estimate based on the number is see in a ten foot square area, I’d say there were 500 or more in our quarter acre yard at a time. Then a year after we moved, a woman moved into the house next door and she rescued three feral cats (I suppose she planned to socialize them). Not only did they use our bird feeders as traps for their bird hunting, but they constantly appeared to be hunting toads. I still see a toad in occasion, but those wild cats left to roam free have decimated our toad population. I sure miss putting them into bed with my sisters-in-law when they came to visit. And so far, I’ve found nobody who approves of my scheme to hunt those feral cats.

  7. Very cool Greg!

    I love frogs – I think they’re cute. Also, whenever I see them I’m reminded of summers on my grandmother’s farm. The lily pond was full of tadpoles, which my siblings, cousins and I would watch develop wee legs and lose their tails. If we put our hands or feet into the pond, the tadpoles would nibble them, and the longer we stayed still, the more would come. We’d spend ages just lying by the pond.

    Eventually they’d disappear as they grew big enough to make their way down the hill to the creek to live their lives out, and we’d try and catch them from time to time. One time we made a pond next to the creek to put all the frogs we caught in, and were very excited to catch a mating pair once, which stayed connected to each other the whole afternoon.

    We were very gentle with them. The cats used to catch them too – they weren’t quite so gentle. 🙁

  8. There is something about the expression of a toad that makes me think that they should be considered honorary owls, only one step away from honorary cats.

  9. One of the most impressive puns I ever encountered was an SF novella which spent about 50 pages setting up a fantasy universe of sword, sorcery and specially-bred, battle-armoured, man-carrying frogs as the organic Panzers of the universe. All so that the author could inject the line “Cry ‘Havoc’ and let slip the Frogs of War”.
    It was appallingly bad. So bad it was good. And though I could tell that something wicked was coming up (my thumbs were pricking) but I was completely blind-sided by the Frogs of War.
    Hmmm, seems to actually be quite a popular trope. But it was new to me in the 1980s.

  10. Wouldn’t it be possible to erect a small (foot-high) barrier around the window well?

    I suppose you wouldn’t have the pleasure of rescuing frogs, then. 🙂

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