The Mysterious Vanishing Frogs of North America Essay -- Environment E

The Mysterious Vanishing Frogs of North America I have a passion for both things slimy, wet, and creepy-crawly. Some of the outstrip times of my life have been spent on my knees, digging in the dirt for earthworms, traipsing back from ponds with buckets of putrid swamp water teeming with tadpoles, or chasing juicy little toads in knee-high grass. I love the outdoors and all of the ugly animals that inhabit it. I like to fancy them, watch them, and especially snarl them. For the longest time, lizards have been the main focus of my photographic endeavors, but last summer, inspired by a book on frogs from the local library, I pock out to document the lives of these often overlooked amphibians. I live in southern Florida near the Everglades, and I remember catching, mating, and raising dozens of frogs as a kid, so I didnt expect to have to lug my tripod and lenses very far to find a suitable subject. But much to my dismay, I didnt find a single frog in an entire afternoon of sea rching. In fact, in the year and half since my initial search, Ive seen only foursome frogs.I immediately assumed that pollution had decimated the populations of my favorite amphibian. I have no hard evidence, but I believe that this is a common look shared by many fellow lay naturalists. This makes scientific sense frogs spend most of their lives in water, have thin, easily permeable skin during all stages of their lives, and lay their gelatinous eggs in water. Pesticides and other pollutants accumulate in water, where they can easily diffuse into the thin skin of frogs. It all seems perfectly logical.The catch is, this perfectly logical and widely believed answer is probably false. While there are never any absolutes in ecology, there is a l... ...y/froglog/FROGLOG-24-4.html Explanation for of course Occurring Supernumerary Limbs in AmphibiansStanley K. Sessions and Stephen B. Ruth The Journal of Experimental Zoology 25438-47 (1990).http//www.hartwick.edu/biology/def_frogs/tre m/Sessions&Ruth.html Sessions research groups web pagehttp//www.hartwick.edu/biology/def_frogs/Introduction/Introduction.html morphologic Clues from Multilegged Frogs Are Retinoids to Blame? Stanley K. Sessions, R. Adam Franssen, and Vanessa L. Horner Science 1999 April 30 284 800-802. (in Reports)http//www.sciencemag.org/cgi/content/full/284/5415/800 University of Wisconsin BioLabhttp//bioweb.uwlax.edu/zoolab/Table_of_Contents/Lab-4a/Trematode_Life-Cycle/trematode_life-cycle.htm Stanley K. Sessions Science 1998 January 23 279 459 (in Letters)