Thursday, March 13, 2008

The Chorus is Back!

Prairiewolf and I have been commenting for several days that it seemed strange we hadn't heard any frogs singing yet...and, lo and behold, yesterday they started to sing!

In the past, I've rather generically thought that frogs singing in early spring were probably spring peepers, but this year I decided to try and learn a little more. For starters, if these were spring peepers, I really had expected them to start singing a little earlier than they did.

So I searched out a CD of night noises that I purchased last fall, looked in the only amphibian reference that I currently have at home (The Amphibians and Reptiles of Missouri) for likely suspects, then listened to the two species on the CD that seemed possible based on the descriptions in the Missouri book.

My possibilities seemed to be either spring peepers or several species of chorus frogs. Listening to the CD, it was obvious that what we were hearing were chorus frogs.

Then it got a little complicated. I went to the web and searched for chorus frogs in Kansas, coming up with definitive looking sources (Great Plains Nature Center in Wichita, Kansas Herpetological Society, and the Kansas Anuran Monitoring Program) that said we only had 3 species: Spotted - Pseudacris clarkii, Boreal - P. maculata, and Strecker's - P. streckeri. IUCN (International Union of Conservation of Nature and Natural Resources) range maps, though, show that the Western Chorus Frog, Pseudacris triseriata, occurs throughout most of Kansas too.

After more research, I think I've resolved the discrepancy, at least in part. Some sources talk about the boreal chorus frog and the western chorus frog as two subspecies of an overarching species. The classification seems to be in some flux currently.

The upshot is that I'm not sure exactly which species we're hearing, but I am sure that it's a chorus frog.

A little biology:

Adults of these species range in size from 3/4" to 1 1/2" in length. Breeding sites are generally temporary bodies of water; after breeding is finished they are often found under rocks or logs, in grass, or even in loose soil or animal burrows. Western chorus frogs, at least, can generally survive in urban areas, unlike many other species of amphibians.

These chorus frogs overwinter underground, but they don't burrow deeply and they can tolerate freezing temperatures due to increased levels glucose in their blood.

Generally, chorus frogs eat a variety of (small) insects and spiders.

Now my task is to try to listen carefully to the calls and narrow down the species that we're hearing. Auditory learning is NOT my strong point, but it will be interesting to see what I figure out.


Anonymous said...

Sigh. There are definitely days/times when I miss the country. I do miss the singing of the frogs.

Gaia Gardener: said...

Listen carefully. Chorus frogs can survive in urban areas, so you may be able to hear them even in your neighborhood. Any streams or wet areas nearby?

Anonymous said...

Kinda sorta. I'll listen, but there certainly aren't any yet.