Wednesday, October 29, 2008
So spending some days in the Mojave gets you acquainted with the locals. While I've seen numerous native fauna, including pack rats, tarantulas and coyotes, there are a couple specialised little guys I really want to see. They're amazingly adapted for desert livin', and they're f'in cute.
Kit foxes (seen here being adorable)are the smallest member of the canid family and are found in the Mojave. image from http://museum.utep.edu/
Kit foxes play a really important role in building really extensive underground burrows that other willife utilize. They are, like most desert life, only active at night. They have huge ears. Apart from detecting prey, large blood vessels running through the large ears of the kit fox close to the skin allow their blood to be cooled and transferred through out the body.
They drink no water, as it is obtained exclusively through the prey.
One of their prey species is the kangaroo rat, one of the most interesting developed little guys out here. I have yet to see one alive, but I've seen this...
So these guys are kooky. They have cooled nasal passages, cooler than their core body temperature. When the little critters exhale, agua vapor in their breath condenses in their nose and is reabsorbed. Genius!
Also, they have a crazy long loop of henle. Alot of animals (even us) have these. Its an actual loop. Urine runs through this U- shaped loop. Ions (K+ and Na) actively moved out of the loops descending quadrant. When these ions are moved out, they swing on over by the ascending quadrant. Cause of how gradients work across a membrane, the water exits the loops due to its attraction to the ions, and water is saved.
These little guys have a really looooong loop, meaning more h20 is returned to the system and not peed out. Their urine is 6x as concentrated as ours when we're super dehydrated.
I return to the desert Friday. I'll try to find some more science out there.