Well, it seems my old friends are uncomfortable about posting comments, but have no qualms having me post them in the blog. Here is Al Gardner's e-mail to me in response to yesterday's jackrabbit posting. His fond memories of caecum research and Costa Rican revolutionaries give a flavor of the conversations we used to have when I stopped by his office on early mornings. If you're not a biologist, it may sound a little goofy, but I include it because...well frankly, we need to be understood.
As always, enjoyed your latest contribution. I am not sure I ever told you of this experience. While living in Costa Rica in the mid-1960s, I was helping a student on a semester internship from a US college. He was interested in internal parasites of bats. At the time, I was unaware that tropical frugivorous bats harbored essentially no GI-tract parasites. (The secondary compounds in the fruit they eat keep them clean). We were not finding any intestinal parasites in the bats we were catching in my yard, so I decided to sacrifice a spiny pocket mouse (Liomys salvini) I happened to have at home, and "posted" it as a demonstration. (I lived in Santa Ana, and with a centrifuge and compound microscope I was fully equipped to carry out lab work in the house.)
We found plenty of parasites, but the real surprise was when I placed the contents of the caecum between two slides and examined the material under the microscope. The slide held a writhing, seething mass of bacteria and what appeared to be microscopic nematodes (in retrospect, they could have been spirochaetes).
According to Dan Janzen, Liomys salvini is a specialist on Guanacaste seeds, which are poisonous. The animal may be a hind gut fermenter and uses the flora and fauna of the caecum to detoxify the otherwise poisonous compounds. Coprophagy of the caecal contents, i.e., ingesting this flora and fauna, would also enhance the overall nutritional content of the diet. Perhaps this is why some animals are hard to keep in zoos, particularly if treated for "worms and other parasites."
My long time helper in Mexico was a former revolutionary. We used to eat guanacaste seeds, but only after the seed pods had been thoroughly cooked in the coals of a fire. On long cold nights tending the mist nets, we would often have a small fire, and this man told stories of the Cristiada Revolution, including the times when they hid from the federal troops and lived on guanacaste seeds roasted in small, smokeless fires.
Alfred L. Gardner
USGS Patuxent Wildlife Research Center
National Museum of Natural History
PO BOX 37012
ROOM 378 MRC 111
WASHINGTON DC 20013-7012"