Monday, October 26, 2020

Bat Appreciation Month!

These spectacular nocturnal creatures deserve nothing but praise all year long. Once you learn the facts and look past the myths you will understand the important ecological roles bats play in our ecosystem. 

Bat Species in New Jersey

Red Bat

We are lucky enough to have nine native bat species that make their home here in New Jersey. Six species call New Jersey home year-round: the little brown bat, big brown bat, northern long-eared bat (northern myotis), Indiana bat, eastern small-footed myotis, and tricolored bat (formally eastern pipistrelle). These species can be found living around the state in warmer months, but come early fall will start to move to caves and abandoned mines to survive the cold winter months by hibernating in their hibernacula. A hibernaculum is a shelter or place occupied by a creature during winter by a dormant animal (a hibernation site). There is one main hibernaculum in New Jersey located at the Hibernia Mine in Morris County. However, three bat species -- the silver haired bat, hoary bat, and red bat -- are tree bats that are migratory and leave New Jersey for more southern states to find milder climates to avoid the cold.

Endangered Species

Eight of the nine bat species can be encountered in Monmouth County; the only bat not found in the county is the Indiana bat, which is found in further northwest New Jersey. The Indiana bat is also the only bat listed with a conservation status as both Federally and State Endangered. However, there are some listed with a conservation status of only State Endangered, including the little brown bat, tricolored bat, northern long-eared bat, and eastern small-footed myotis. All of our remaining bats -- big brown bat, silver-haired bat, hoary bat, and red bat -- are listed as a conservation status of special concern. One of the reasons for some of these conservation concerns has much to do with a disease caused by a fungus that affects hibernating bats called White-Nose Syndrome, which has been an issue across the country. 

Time to Eat!

All New Jersey bat species are aerial insectivores, meaning they only eat insects they catch out of the sky mid-flight. Since bats are nocturnal predators, they have evolved the special adaptation of using echolocation to help locate and capture prey. Echolocation uses sound waves given off by the bats mouth or nose to reflect off objects to determine where those objects are in a space, once the reflected sound waves return to the bats ears. Most bats are thought to have poor eyesight, but this special adaptation makes up for it. 

Bats can consume more than half their body weight in insects every night, especially females when taking care of and feeding young. It is estimated bats can consume up to 3,000 insects in a single night with nursing mothers consuming even more. Common insects eaten by bats range from mosquito sized prey to beetles, moths, termites, leaf hoppers and even grass hoppers and are known to be a good natural pest control without the need for chemical pesticides. They mostly forage in flight in open areas, but can also glean insects from tree branches and leaves. They need to eat and drink nightly preferring habitats of forest edges and fields close to open bodies of water. Bats drink by gliding down to the water and drinking mid-flight without ever landing.

Taking Time to Rest

Little Brown Bat

The only time bats usually land is when they are ready to roost. During the day, a natural roost can consist of cracks in rocks, small caves, and under tree bark, but sometimes manmade roosts, such as bat boxes and awnings of buildings, are used as well. Bats need to roost during the daytime to help keep a stabilized temperature as well as to protect themselves from predators. Most daytime roosts are inconspicuous and hard to locate with the exception of those that are manmade. Bats are famous for being able to hang upside down while roosting and have a special adaptation of a tendon in their toes that locks into place for a firm grip.

Bats, like humans, are mammals! 

Bats have bodies covered with hair, are warm blooded, give birth to live young, and have mammary glands that produce milk to feed their young. The only true flying mammal, bats are actually in their own order of mammals called chiroptera, which means “hand wing” in Greek. The wings have four fingers and a thumb covered by a thin membrane of skin. They are one of the slowest reproducing mammals for their size on the planet, many only having one to two offspring per annual cycle (called pups). They engage in mating in the fall before hiberation, and give birth in the spring. The pups grow to full size within a couple of months, normally around mid-summer.



Sources:
  • Conserve Wildlife Foundation of New Jersey, http://www.conservewildlifenj.org/. 
  • White-Nose Syndrome Response Team, https://www.whitenosesyndrome.org/. 

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