My friend Peter and I headed out Tuesday evening for our first frog run in southeast Ann Arbor (map of our route is here.) It had reached a high of nearly 70F and it was still in the 60s in the evening. So even though it was a little windier than ideal, we hoped frogs would be calling for one of the first times in the season. And we were right!
We heard western chorus frogs (Pseudacris triseriata triseriata) at all but one location, and they were accompanied by spring peepers (Pseudacris crucifer) in one spot.
Western chorus frogs remain at their breeding sites all year, liking to hide under logs, rocks, leaves, or soil when not in the water mating. Chorus frogs are fairly abundant in Ann Arbor-area marshes, meadows, swales, damp woods, and swamps. All sites on our route are ponds (vernal and permanent) on the edges of woods or small wooded areas. Even in the ponds, they prefer dead grasses and reeds for camouflage.
Peter made sound recordings of the frogs at two locations using his spiffy silver music recorder doohickeythingamabob. The first recording is of chorus frogs at a pond on the northwest corner of Stone School and Morgan Roads in southern Ann Arbor. The frog calls sound a bit louder than I remember, probably because the location is on a dirt road with few traffic/background noise distractions. The second recording is of a chorus of chorus frogs and a few spring peepers at a detention pond in Turnberry subdivision, at Turnberry Lane and Ca Canny Court (I'm not making that name up; all streets in that sub are named after golf courses in Scotland). The frogs actually sounded much louder in real life, even over the traffic noise from nearby US-23; I actually had to raise my voice so Pete could hear me! It was awesome, though of course it makes perfect scientific sense that frogs in detention would be more rowdy!
I had hoped we might hear a wood frog (Ranus sylvatica) as well, as I've never heard this species in my five years of doing the frog and toad survey. They are "explosive breeders," which brings all kinds of unsavory images to mind, but which means they mate early in the season and only for about two weeks. I hope I haven't missed them.
For more photos and another sound recording of chorus frogs, jump on over to Gerry Wykes of Naturespeak .
Western chorus frog photo by Jim Harding