Posted On: October 28, 2019

Eastern Red Bat

Eastern Red Bat

Our team spotted an Eastern red bat just in time for Halloween. Scientifically known as the Lasiurus borealis, it is one of our native tree nesting bats which can be found in trees anywhere east of the Rockies, making it one of the most common bats in the U.S. 

Often nesting in trees, shrubs, and roofs—away from dense human habitation—they are occasionally spotted in crowded urban areas, including Madison Square Park! Their preferred nesting sites include sycamore, oak, and elm trees, which are in abundance in the Park and one of the reasons that this species of bats was sighted.

These fast flying bats live throughout the Americas, and are large with an average wingspan of 13 inches. Most bats spend the warmer months migrating to the southern reaches, looking for warm weather and an abundance of insects. However, some Eastern red bats do not migrate and have been seen active in the colder areas of their range. During winter, L. borealis hibernate to conserve energy and limit exposure to low temperatures. The increasing number of warm days during the winter months has decreased insect populations greatly, impacting the local bat population as the warm days awaken bats from migration only to find no insects to eat. 

Eastern red bats, like many bats, are voracious insectivores consuming insects of all kinds.

Beginning their hunt at dusk, they are quick fliers and prefer to hunt within 500 meters of a light source, likely as their insect prey are attracted to the light. Prey varies depending on the location and season, but the most common insects eaten are beetles and moths. L. borealis has a very distinct means of attack, following their prey in a very steep dive that can take them within inches of hitting the ground before they pull up. This is often mistaken for aggression on the part of the bat, as people are unable to see the tiny moths the bats snack on. 

Bats are important members of our ecosystem. Their diet of insects, including mosquitoes, is beneficial to humans and helps prevent the spread of mosquito borne illnesses. If you see a bat in the Park, log your sighting at Madison Square Park on our iNaturalist Wildlife Project. This page can better help the Conservancy understand our urban ecosystem and allow us to create a Park that benefits people, plants, and animals. 

Bat Facts