Bats have been in the news recently due to their potential as a source of the COVID virus.
Bats are mammals just like us, but eons ago they evolved lightweight membranes between their fingers and forearms and took to the sky, the only mammals to achieve true flight. Because they are mammals, they can harbor viruses that can more easily cross over to humans.
Bats are the second largest group of mammals with 1,400 species, and it is this species richness that makes them a larger reservoir for a variety of virus including SARS-CoV-2 (COVID-19).
But not all bats are carriers, and it is agreed by scientists that crossover requires direct contact; either consuming, handling, or breathing/ ingesting contaminated feces.
Bats are found worldwide except in very cold areas, and range from the tiny Kitti’s Hog-nosed bat at 1 ½”, the smallest known mammal, to the Flying Foxes, fruit-eating mega bats with a wingspan of over 5 feet.
Despite this size the Foxes only tip the scales at 3 pounds because flight requires light weight.
Bats in flight are highly maneuverable allowing them to catch insets on the wing. They can even net an insect in their wing membrane and use their legs to move it into their mouth, without missing a wing beat. Bats in our areas are primarily insectivores, consuming up to 600 mosquitos and other insects in an hour.
Bats are not often seen since they are nocturnal feeders. Their nighttime habits make surveying them difficult, but scientists have developed several methods. One is using fine-meshed mist nets.
A newer method is taking sonic recordings while driving through areas with active bat populations. Each bat species has a unique echolocation signature that can be identified.
Bats use echolocation to navigate and find food in the dark by sending out sound waves from the mouth or nose. When the sound waves hit an object, an echo bounces off the object and returns to the bats’ ears.
They produce sound waves above human hearing, called ultrasound, but in certain circumstances it can be heard. I was privileged to be in a walled square in Italy with bats swirling around over our heads. Their calls bouncing around in the enclosed space were audible as a high clicking chatter.
Little brown bats were once the most common bat in the east, but the advent of White-Nose Syndrome is decimating their populations. New York is ground zero as the first cases were discovered in caves near Albany in 2007. This fungus lurks in the caves where bats hibernate in winter.
It causes bats to behave abnormally, doing things like flying outside in winter, and leads to death. It has spread rapidly and has been detected this year in Texas and Montana. It is thought the vector is cavers carrying the fungus on clothing and equipment so protocols for entering new caves have now been put in place.
New York State is home to nine different species of bats including the Red bat, Hoary bat, Silver-haired bat, Northern long-eared bat, Little brown bat, Indiana bat, Tri-colored bat, Big brown bat, and Eastern small-footed bat.
Recent surveys in Suffolk have not seen large numbers of bats, though several different species were identified. In 2017, during a 10-day mist-netting survey at two refuges, Wertheim and Elizabeth A. Morton, scientists caught 6 Eastern Red bats, one Northern long-eared bat and 26 Big brown bats. An acoustic survey in the Pine Barrens identified five species: the Big brown bat, Hoary bat, Tri-colored bat, Northern long-eared bat, and the Red bat.
These low numbers may be attributed to a lack of suitable hibernating and roosting spots. Bats need to hibernate in groups in order to stay warm. Wind turbines and deforestation have also played a role in dropping numbers of bats.
The lack of roosting sites can be remedied with the installation of bat boxes. They need to be properly sited and constructed. A bat house is just an empty rectangular wooden box with an opening at the bottom.
The bats roost inside hanging upside down, squeezing in tight with others for warmth. Bat houses should be mounted facing south, 12 to 15 feet above the ground on a pole or under the eaves of a house. Unlike birds that can fly off their perches, bats have weak legs and upon leaving the house need to drop a few feet before flying.
Bats are important in the ecosystem for the control of insects. Recent studies estimate that bats eat enough pests to save more than $1 billion per year in crop damage and pesticide costs in the U.S. corn crop alone.
Bats also spread fruit seed and are pollinators of night-blooming flowers, sustaining many ecosystems worldwide. The International Union for Conservation of Nature estimated in 2012 that “Production of at least one-third of the world’s food, including 87 of the 113 leading food crops, depends on pollination carried out by insects, bats and birds. This ecosystem service is worth over USD200 billion per year.”
Bat Myths Busted!
Bats will fly into your hair and get stuck
This old myth that was used to keep young girls from going out at night. In reality bats are not interested in flying into your hair and getting stuck to a screaming maniac.
All bats carry rabies
The estimated number for free-ranging bats is less than 0.1%. Bats that are infected with rabies will act strangely and are often lying on the ground. Rabies can be fatal, and care should be taken not to touch bats, even dead bats.
Bats are flying rodents
Bats belong to the order Chiroptera, and rodents belong to Rodentia.
Bats are blind
Bats use echolocation, but they can also see and have well developed eyes.
Bats are blood feeders
Only three species of bats feed on blood and those live in tropical regions of the Americas. The majority of bats feed on insects, fruit or nectar.