Bats: Unloved animals that can be of great help

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I have always thought that bats were unlovely creatures and somewhat sinister to boot. It may go back to that night when we woke up and heard something flying around our bedroom and it turned out to be a bat that had clearly lost its way. I opened a window so it could find its way out but it was probably as crazed as I was, and the adventure ended badly.

However, as I have become more entranced by bird watching, I have found myself at Wild Birds Unlimited on Route 17 in New Jersey on several occasions. I was surprised to find that in addition to birdseed, binoculars and guidebooks, they had material about bats, as well as bat houses. Yes, you can try to induce bats to move to your property. The first question was why would you want to do so. But I did buy two guidebooks about bats trying to learn something that might enlighten me. The gripping words were: “a single, little brown bat can eat from 500-1000 mosquitoes in a single hour” – and I was won over.

And so, I found myself the other night at a “Batstock” wildlife program in Ridgefield, New Jersey. Joseph D’Angeli of NJBatman.com brought several caged bats with him and spent over an hour speaking about the role of bats in ecology, showed slides and took questions. He brought fruit bats and showed the audience how they eat chunks of ripe fruit presented through the cage on skewers. Fruit bats apparently do not swallow solid food, and after they take the fruit into their mouths, they strain it of the juices and spit out the residue, which includes any seeds present in the food. What becomes readily apparent is that they, thereby, act as important agents in seed dispersal.  And despite the fact that fruit farmers have not been happy with their presence – assuming that they damage crops – they only feed on fruit that is too ripe to ship. Although other species will disperse seeds also, the bat is willing to cross large denuded areas in search of food – unlike birds, which will avoid doing this because of fear of predation.

Most bats fall into two separate categories. There are the Old World megabats, which comprise the fruit bats, also known as flying foxes. Despite my earlier characterization of bats as unlovely, the flying foxes are actually quite cute, looking like inquisitive puppies. Then there are the insectivorous microbats, which have the unusual snouts and over-large ears. Some of the larger microbats will also hunt lizards, other bats, birds and even fish.

Echolocation –the method of locating prey based on bouncing sound waves off solid objects – is the basis for sonar (the acronym for Sound Navigation And Ranging) developed by the Navy. Bats send ultrasonic waves from the larynx through the nose or open mouth and hear the return “echo” through their enlarged ears. Some moths have developed defenses against detection but the bats are evolving their own counterstrategy.

Bats also act as pollinators and are especially important in desert areas where they pollinate many of the cacti.  Bananas, mangoes and guavas are three of the agriculturally important plants that they also pollinate. The characteristics of bat-attracting flowers include: opening at night, relatively large in size, white or pale coloration, highly fragrant, and having dilute but copious nectar.

Bats are under serious population pressure. In addition to the usual man-made problems, they are suffering since 2007-2008 from a fatal fungal infection caused by Pseudogymnoascus destructans and known as White Nose Syndrome, which infects the skin, muzzle and wings. There is some recent indication that bats are developing some immunity to the fungus. However, because most of these bats have only one pup a year and the losses have been in the millions, it will take many, many years to re-establish population levels.

If you, like me, are contemplating a bat house, there are several suggestions about situating them. They should be hung on a tree trunk between 15 feet to 18 feet off the ground. They should be facing southeast in order to get the sun. It seems that bats, despite being mammals, have difficulty in regulating temperature and appreciate warmth from the sun. Old trees with rotting “snags” attract them but we tend to cut them down quickly.

Because it rained the night of the lecture that we attended, we missed the batwalk. However, we will have another chance on Sunday, Sept. 18 at 7:00PM through the Teaneck Creek Conservancy at 20 Puffin Way, Teaneck, New Jersey (201-836-2403 or 201-257-2231). Pre-registration is appreciated. Maybe I’ll see you there!

green scene, Sura Jeselsohn

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