Thursday, November 17, 2011

Tortoise Bones

Last week we found this scute, a section of shell from a Sonoran desert tortoise (Gopherus morafkai), lying at the edge of a trail we were biking on. Recognizing that it had to have been attached to a rather large tortoise, we explored the area and within minutes found the still smelly, decaying remains of an ancient male. Measuring 12” long and 8” wide (30cm x 20cm), this guy must have been in the upper end of the 80-100 year life span. The crack in his shell tells another story, perhaps a fatal tumble down the rocky hillside where he once roamed. A dozen more scutes were scattered about, although many are missing after three separate visits to look for the old one’s burrow, which we also haven’t found.

This is the second tortoise shell I’ve found in the Deem Hills, a desert island that backs up to the neighborhood we live in. The home of this desert tortoise is just a few blocks from my own; both are visible in this photo. Next time I cross paths with a wild tortoise, I hope that it’s a live one!

Through analysis of DNA and other characteristics, tortoises that live east and south of the Colorado River were recently distinguished from the Mojave desert tortoise (Gopherus agassizii) as a new species. Read more in this June 2011 scientific publication on tortoise taxonomy.

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