Tag: Indiana bat

Enhancing Bat Roosting Habitat in NJ’s Forests

Posted by MacKenzie Hall, Private Lands Biologist

Kyle Whittle, a Boy Scout from West Milford, will earn his Eagle rank soon for a project that adds summer roosting habitat for forest bats.  Dwindling habitat is a threat to NJ bats – even those that aren’t affected by White-nose Syndrome – and most of our 9 species need dead/dying trees with flaking bark to roost and raise their young.  Artificial roosts can also be successful and long-lasting.  Kyle chose to put his Eagle-eye on bats after hearing about our Indiana Bat Forestry Project through a family friend with several wooded acres to offer.

Last week I worked with Kyle and a group of his friends to mount bat roosts at the West Milford property, which sits on the edge of the Bearfort Mountains.  We hiked up a steep hill of rhododendrons and hemlocks to the deeper part of the forest…a really enjoyable walk without the ladders, hammers, bundles of cedar shakes, asphalt paper, screw guns, and 15-lb bat houses!

The afternoon made good use of the teenagers’ energy, carpentry skills, and tree-climbing impulses.  They put up four traditional bat houses, built earlier by Kyle, and a few tree “wraps” meant to resemble the loose bark of dead trees.  We chose trees that get a lot of sun during the day; the owners will also do some girdling to open the canopy and create natural roosts.

Bats are starting to show up in their summer grounds again.  Thanks, Kyle & crew, for rolling out the welcome mat!

By Maria Grace, Education & Outreach Manager

Bats get a bad rap – they are blind bloodsuckers that get caught in our hair. But these are all myths and this post is going to bust them!

There are no bloodsucking bats in the U.S. Yes, there are vampire bats in the world (3 species live in the tropics from Mexico to Brazil, Chile, and Argentina) and while they do rely on blood for their sustenance, they don’t view people as a food source.  They usually pierce the skin of livestock such as cows, goats or chickens, and gently lap the blood from the wound (similar to how a dog licks water from a bowl).

Bats are not blind. Most species of bats have very good eyesight but they usually depend on their sense of echolocation to navigate through the world.  They emit high frequency sounds into their environment and these sounds bounce off objects and back to the bat.  The bat is then able to interpret the sounds and create a picture of what their environment looks like.

Bats rarely get caught in human hair. Bats, using their sense of echolocation, can detect objects as fine as a single human hair in total darkness.  They are not aggressive animals but they can fly too close to people while feeding on insects or when flying low over water to take a drink.

Beneficial bats eat bugs. Bats are incredible animals and do a lot for us.  All nine species of bats found in New Jersey eat insects, consuming one-third of their weight in bugs each night.  Bats play essential roles in keeping populations of night-flying insects in balance. Just one bat can catch hundreds of insects in an hour, and large colonies catch tons of insects nightly, including beetles and moths that cost American farmers and foresters billions of dollars annually, not to mention mosquitoes in our backyards.

Bats play a key role in pollination. In other areas of the world, bats are the primary pollinators for many desert plants like the saguaro and organ pipe cactus as well as many species of agave.   Bats also help in the pollination of fruits and veggies like bananas, avocados, coconuts, vanilla, dates, and mangoes.

Bats also help in seed dispersal.  In fact, seeds dropped by bats can account for up to 95 percent of forest regrowth on cleared land.  Bats spread the seeds of almonds, cashews, and chocolate.  Did you read that?  CHOCOLATE!  Bats help us to have more cacao trees, which produces the yummy main ingredient of our favorite Halloween treats!

So instead of screaming and freaking out if and when you see a bat, why don’t you stop and appreciate it and maybe say a little “thank you” for all the wonderful benefits they provide to us.  Halloween wouldn’t be the same without bats and the delicious m&m’s, snickers, and Almond joys are made possible because of the wonderful, now better understood, bats of the world.

Musings from Austin, TX as our own project gets underway in New Jersey.

By Brian Henderson, GIS Specialist

In April I attended the Anabat Techniques Workshop in Illinois with MacKenzie Hall. The following month I took a brief trip to Austin, TX.

The trip wasn’t work related, and was planned before I knew I would be helping with our bat monitoring work in New Jersey.  But it was appropriate because Austin happens to be home to the largest urban bat colony in North America.

Located near the center of the city, the Congress Avenue Bridge spans Lady Bird Lake, a reservoir on the Colorado River.  Renovations made in 1980 created ideal roosting habitat along the bottom of the bridge and it wasn’t long before migrating bats discovered it.  Now, estimates are that 1-1.5 million Mexican free-tailed bats roost below the bridge between March and November.  Each night around dusk the bats exit the bridge to forage for insects along the river.  When conditions are right the effect is dramatic: a column of bats silhouetted against the setting sun that can last for 45 minutes as the bats exit the bridge.  Although there were petitions to eradicate the bats when they first took up residence, the city has come to embrace them and it isn’t unusual for several hundred people to line up along the bridge on summer nights to watch the bats exit and begin foraging.

Unfortunately, it was cloudy and slightly cool on the evening I visited the bridge and the bats waited until nearly dark before starting to emerge.  It was difficult to observe the bats except in the illumination of the streetlights lining the bridge or when they veered closer to the shore.  Although it wasn’t the spectacle I’d been hoping for, it was still impressive.  Even under less than ideal conditions I saw hundreds (possibly thousands) of bats-more than I observed in the week of training in Illinois, and probably more than in the rest of my life combined.

Here in New Jersey we don’t have Mexican free-tailed bat and we certainly don’t have any bat populations that rival the numbers of the Congress Avenue Bridge Colony.  Even before the arrival of white-nose syndrome populations at our largest hibernacula numbered in the tens of thousands, not millions.  So it was exciting and encouraging to see such a thriving bat population in person.  It was also impressive to see how the city has embraced the colony as a beneficial, unique and interesting attraction.  Similarly, the response to our acoustic monitoring project in New Jersey has been overwhelmingly positive.  Landowners and the general public all seem interested in learning about bats, concerned about white-nose syndrome, and are eager to help however they can.

My experience in Austin was also a reminder that even at the best locations, there are  variables that affect what you observe on any single night.  Rain or cool weather reduce bat activity, and there’s still a lot we don’t know about bat foraging behavior; for instance they may actively forage in an area one night but not the next.  So negative results during one visit isn’t enough evidence to decide bats aren’t in the area.  Ideally we would visit each site multiple times to control for this variability.  However with fifteen sites to monitor, only a few staff members and a fairly short survey period (roughly June 1st to July 31st) we know getting to each site once will keep us busy.  As a result, we may have to survey some sites even though the conditions aren’t ideal.  Unfortunately, these are common problems when surveying for endangered species and are something that many at CWF have had to deal with.

Our acoustic bat monitoring project is just getting underway; we’re taking the lessons learned in Illinois and using that knowledge to monitor for bats in New Jersey.  Expect more updates on our techniques and preliminary results as we have a chance to visit more sites.