Chicago Nature Blog: Bachelor's Grove Bullfrog

About a couple weeks ago, Aimee, my nephew Jeffrey (Peffers) and I took a trip down to Tinley Park for the bi-annual North American Reptile Breeder's Conference (NARBC). I've attended the conference most years since its inception, and it's always fun to see familiar faces in the reptile industry (I worked in that industry for a long time, some time ago). After a few hours of viewing the animals and chatting with a few fellow enthusiasts, we decided to head out. On the way home I thought it would be fun to stop by Bachelor's Grove cemetery, located in Midlothian. It was on our way anyway, and seeing as it was the season for spooky haunts, we parked the car in the parking lot across the street from the entrance, crossed the street, and soon were on our way to one of Chicagoland's most infamous cemeteries. Jeffrey had never been there before so we had to school him on what it was all about. After taking some photos in the cemetery, I decided to show him the creek, the old house foundation, and stone-lined well in the woods. We spent a good deal of time at the creek, which at this point had dried up considerably. There were very few sections of the creek that were connected; there were many isolated pools with only a very tiny trickling of water that fed them. The creek was lined with limestone and pebbles and autumn leaves were everywhere. The "bigger" pools contained schools of small minnows, while the smaller ones contained a few lonely stragglers or were vacant. As we strolled along the dry rocky bed, I noticed a few small "plops" of frogs entering the water. To be honest, I was surprised to see any active amphibians, since it was quite cold out. I was able to catch one of the small frogs after it had jumped in; it was trying to hide by staying motionless at the bottom of the pool like most frogs do, but it didn't do a very good job. I reached my hand into the icy water and brought it to my nephew so he could see. It was a young bullfrog, Rana catesbeiana. After explaining to Jeffrey a few interesting features of the bullfrog, I released it back into the water, but not before noticing that it suffered a deformed back leg. As it slowly swam through the cold water, I clearly saw that one leg was smaller and weaker than the other. It influenced the way the frog swam, and I imagine it being detrimental to the frog's future development. This was certainly not the first time I've seen this kind of deformity in Rana. I have seen it occur where frogs live with polluted water. Retention ponds and streams with discharge pipes releasing runoff often produce animals with similar debilitating features. This water seemed clear and clean, and being in the forest preserve, one would assume it would be fit for frog life. But there could be something upstream causing this problem - runoff drainage, industry, etc. It doesn't take much to impact downstream amphibian populations. I just hope that I'm wrong and that this was an isolated, freak frog.

Fragmented stream