Julie Says - Let's Hang Around Together
Oct 02, 2017 10:31AM
● By Julie Ross
Question: What did one bat say to another? Answer: See headline above.
Yes, it’s getting close to Halloween, when it’s time to turn our attention to costumes, candy, and all things scary. October brings little time for me and my fellow volunteer wildlife educators at Lindsay Wildlife Experience to just hang around. Teachers from all over the East Bay have arranged for us to come to their schools to present programs about Halloween-y animals like bats to complement fall-themed lessons and activities.
Lindsay Wildlife education volunteers love to talk about bats. Like many of you, most of us used to think bats were somewhat on the creepy side. But once we spent time observing bats and learning more about them, we came to appreciate their unique adaptations and realize their importance in keeping our ecosystem in balance. Education is a powerful tool to dispel fear, and we like being a part of that.
In July, a group of us went on a field trip, a “Bat Walk and Talk,” offered by the Yolo Basin Foundation. Under the Yolo Causeway on I-80 near Davis lives a colony of 250,000 Mexican free-tailed bats. At dusk in the summer, you can see them flying under the causeway for quite a distance, like an airborne river of bats, until they hit a point they have designated as the mouth of their “cave,” whereupon they all swoop and flit upward in a fantastic swirling cloud formation. It is an amazing sight to behold.
These bats can fly to an altitude of 10,000 feet at speeds up to 90 miles per hour and will fly for as many as 50 miles to find food. In the process, they consume a vast quantity of agricultural pests. The bats in the Yolo Bypass Wildlife area eat the equivalent of approximately 500 grocery bags full of insects every night, representing enormous savings in pest-control costs for farmers.
Besides Mexican free-tailed bats, there are several other bat species commonly found in our area, all of which eat primarily insects and other arthropods they find through echolocation.
Some of you will be delighted (and others disappointed) to learn that there are no vampire bats in California. The three kinds of vampire bats -- common, hairy-legged and white-winged -- are found in tropical areas of Mexico and Central and South America. Bats are the only mammals that fly, and vampire bats are the only mammals that feed entirely on blood.
Because of their diet, vampire bats naturally are named after actual vampires. Here’s the difference: A vampire is the corpse of a former human that leaves its grave at night to drink the blood of the living by biting their necks with long, pointed canine teeth. (Oh, that just made me shudder – I clearly have still not recovered from watching the movie Count Yorga in high school.)
Vampire bats, on the other hand, are only about the size of your thumb, with a wingspan of around seven inches, and they weigh no more than two ounces before they feed. They tend to bite animals on the leg with their razor-sharp teeth. Vampire bat saliva contains an anticoagulant to keep the blood from clotting. A vampire bat licks up the freely flowing blood with its tongue and can consume an ounce or two in about half an hour, often doubling the bat’s pre-dinner weight.
OK, now that I think about it, maybe the blood-licking vampire bats do push the needle fairly high on the creep-o-meter, but really, certainly way lower than Count Yorga and his ilk.
While we definitely want to be on the lookout for the Count and his cohorts this Halloween, at least it’s not likely we’ll need to worry about the little flying mammals in our neighborhoods. Whew.
Be safe, and have a Happy
You can reach Julie at [email protected].
Check out volunteer opportunities and school programs offered at Lindsay Wildlife Experience at www.lindsaywildlife.org.