Our Local Bats

This is the time of year that it’s easy to spot bats flying in the evening sky. After the sun goes down, but before it’s full dark, fast black blurs can be made out against the sky, darting quickly this way and that as they grab flying insects in mid-air. They are social, helpful to man and are critical to the ecosystem, yet they are misunderstood and often maligned. Many fear them as bloodsuckers or carriers of rabies, but the truth is they do nothing but good for us. A single brown bat, one of the more common bats locally, is eating up to 500 mosquitos an hour as they flitter about in the dark. Imagine what life would be like without them.

A few bat facts:

There are about 27 different varieties of bats in the LA area.

They live a long time, as long as 30 years.

They aren’t rodents. They are more closely related to dogs and horses.

As we all know, bats hunt bugs with echolocation. They squeak out a high-pitch sound, which bounces off the flying insect and returns to the bat – an echo. They determine the direction of the insect by the direction of the echo and take off after them.

Bats often have bizarre looking faces and ears with strange wrinkles and protrusions, giving them a fierce alien look. The bats’ ugly faces are actually designed to channel the returning echo into their ears.

The squeak they use for echolocation is at such a high frequency that the human ear can’t hear it. And that’s a good thing, because those squeaks are phenomenally loud, as high as 140 decibels! (The threshold of pain for human ears is 120 decibels.) If those squeaks were in the frequency range of human hearing, we’d have to wear ear protection at night.

Bats are not blind. Their eyesight is as good as ours. They seem to use their eyesight for flying and echolocation for hunting the tiny bugs their eyes would miss, a cooperative venture between the two senses.

In spring, they form maternity colonies to help cooperatively with raising their pups.

They have (usually) one baby at a time and nurture them. They’re mammals so they produce milk for their young. If disturbed, they will carry their young away to safety.

If a member of the colony is injured, the others will feed them.

Since we don’t have a lot of “bat caves” around here for bats to sleep in during the day, they mainly sleep in trees, and sometimes under the eaves of houses or in rock crevasses on the hillsides.

Although none live around here, a few species of bats eat nectar like hummingbirds and, like hummingbirds and bees, they pollinate a wide variety of plants. Bats are primary pollinators for cocoa plants that produce chocolate and agave that produces tequila.

Thank you bats!

Bats are a fun part of summer evenings, entertaining to watch. They’ve adapted well to our urban environment.

If you’d like to view bats, head outside on one of our upcoming warm, still summer evenings. Although you can often see them right in front your home, heading out to where there are bodies of water, such as Devil’s Gate Dam, is a good bet. There are more mosquitos there.

Bats are also attracted to the insects that congregate at night around the big floodlights commonly found on athletic fields. To enhance the viewing experience, “bat detectors” can be purchased. These fairly inexpensive hand-held devices will pick up the inaudible high-frequency calls of bats and convert them to audible sound levels, some devices even identifying the species of bats and whether they are feeding or just communicating. Many models exist that are dedicated units, while an increasing number are apps for smartphones with receiver attachments that plug into your phone.

Next time you see bats darting around the sky of a hot summer evening, think about the great service they do us. Our summer nights would be pretty miserable without them. Thank bats for the mosquito bites you don’t have.

  mike lawler