San Diego Natural History Museum--Your Nature ConnectionSDNHM Exhibits
questionsNatural Treasures: Past and Present

Questions visitors to the exhibit ask most often:

When do you feed the rattlesnake? What does it eat? Where'd you get it? How old is it?
Are the other animals real? How are they stuffed or mounted?
Where are the old exhibits?
Where are the dinosaurs?


When do you feed the rattlesnake? What does it eat? Where'd you get it? How old is it?


We feed the rattlesnake every Wednesday. We give it two or three euthanized mice. Both the snake and the mice are from the San Diego Zoo. The snake is a Speckled Rattlesnake. It is about five years old and weighs about three pounds. We use snake hooks to pick him up. (He's probably a male, though that hasn't been determined for sure.) He likes to lie on the rock to bask in the heat. The Speckled Rattlesnake has the most potent venom of the four poisonous snakes found in the San Diego County. It's also very difficult to see, since it blends so well into granite rocks it frequents.


Are they real? How are they stuffed or mounted?


Some of our specimens are taxidermy mounts which are real animal skins stretched over a form or manikin. The animal forms used in older mounts were wire armatures wrapped with yarn, cotton or other materials to simulate a body with muscle and bone. More modern mounts like our mountain lion, employ a form of molded foam with much more accurate anatomy. They can be purchased from taxidermy supply houses and are available in several poses.

Some specimens are freeze dried. In this process most of the animal's body is used. The animal is positioned and frozen. It is then placed in the vacuum chamber of a freeze-drying machine. The specimen in the chamber is kept frozen at below atmospheric pressure. This allows the ice in the specimen's tissue to escape directly as water vapor. This is called sublimation. The water vapor condenses as ice in the machine's condensation chamber. Since the water does not go into a liquid state before it evaporates, the specimen does not shrivel and maintains its original volume and shape. The finished specimen is sturdy and light weight, like a piece of balsa wood. This process is especially good for soft invertebrates and reptiles.

Natural Treasures