New Jersey Conservation Foundation
New Jersey Conservation Foundation Menu
NJCF Homepage Contact Us Donate Events Search NJCF
New Jersey Land Conservation Organization
Donate to New Jersey Conservation Foundation
State We're In New Jersey Conservation Foundation Blog
While bats hibernate, scientists hope for survival
11/2/2017 Volume XLVII, No. 44

As temperatures cool and daylight hours shorten, New Jersey’s non-migrating bats have gone into hibernation.

For the last decade, hibernation for New Jersey’s bats has been unusually precarious. A disease known as white-nose syndrome – caused by a fungus – has decimated many bat species by scarring their wings and disrupting hibernation patterns, causing them to wake and fly around when they should be sleeping. After depleting their energy reserves, the bats die from starvation, thirst and exhaustion.

The little brown bat is most affected. This once common bat has now lost nearly 99 percent of its population. In 2007, before white-nose syndrome struck, the state’s largest bat cave (or hibernaculum) – the old Hibernia Mine in Morris County – was the winter home for 34,000 little brown bats. Today, the number is down to about 400.

But there may be hope. The devastating losses appear to be leveling off. MacKenzie Hall, a biologist with the state’s Endangered and Nongame Species Program, said the year-to-year survival rate for little brown bats is almost back to normal. “They’re still not growing in number, but they’re almost leveling,” she said.

Scientific understanding of white-nose syndrome is expanding, due in part to the contrast between the plight of little brown bats and the success of another New Jersey species, big brown bats.

Big brown bat numbers are growing, and they seem unaffected by white-nose syndrome.

Why? One difference between big browns and little browns is where they hibernate. Many big brown bats hibernate in cold, dry attics instead of caves, reducing their exposure to the warmer temperatures and higher humidity found inside caves and abandoned mines. Big browns that do hibernate in caves stay closer to entrances, where the temperature is cooler.

According to Hall, laboratory studies have shown that the white-nose fungus grows best between 41-50 degrees. These temperatures are found deep in caves where little brown bats hang out. The fungus does not grow as well below 41 degrees.

Recently, Hall said, the state removed part of an old concrete wall that blocked air flow into the Hibernia Mine. This may drop temperatures slightly, inhibiting the growth of white-nose fungus in places where little brown bats hibernate.

Big brown bats also have different feeding habits. Hall said researchers from Fordham University found that the wings of big browns have a buildup of fatty acids, most likely from the type of insects they eat. These acids appear to prevent the fungus from growing and damaging fragile wing membranes. “It could just be a fluke of nature, these small differences in diet,” Hall noted.

Genetics may also help bats survive white-nose syndrome, according to a study by Rutgers University researchers, who are working in cooperation with the Endangered and Nongame Species Program. The one percent of little brown bats that survive white-nose syndrome seems to be passing immunity on to their offspring.

This winter, biologists will carefully monitor bat caves in New Jersey and look for signs of improvement for little brown bats and other species affected by white-nose syndrome: northern long-eared bats, tri-colored bats and eastern small-footed bats. All four have been recommended for inclusion on the state’s endangered species list.

“There’s been a pretty helpless feeling in the last 8-10 years,” Hall said. “But if there’s any silver lining, it’s that people are appreciating bats a lot more.”

Bats are our only flying mammals, and they’re hugely beneficial. Bats are the single largest consumer of night-flying insects – including mosquitos, beetles and moths - and the value of this natural insect control to agriculture in the U.S. is estimated at $22.9 billion dollars per year.

Want to help bats in your neighborhood? Install a bat house for summer maternity colonies. Leave some dead or dying trees standing so bats can roost behind the loose bark.

If you discover bats in your attic or home, don’t try to remove them on your own.  Call a bat removal expert, who will safely “exclude” them. The Conserve Wildlife Foundation of NJ and Rutgers provide free bat houses to those who evict bats safely.

For more information on New Jersey’s bats, go to the Rutgers website at or the Conserve Wildlife Foundation website at  Another great resource is Bat Conservation International at

And to learn about preserving New Jersey’s land and natural resources, visit the New Jersey Conservation Foundation website at or contact me at



Still the Garden State!

Protect New Jersey's wildlife homes

Preserved lands protect clean air and water

To tree or not to tree?

Hard cider in the Garden State

Turkey Time

American shad return to New Jersey river after 173 years

Act now to avoid worst climate impacts

NJ Natural Lands Trust celebrates 50 years

Must love bats!

Move and improve your health!

Renewable energy: Save money and our land, water, air and health

Speak up for endangered species!

Save the bugs!

Check out New Jersey's fall bird migration

A little bit of respect...for native plants!

Explore New Jersey's wildflower meadows

All aboard floating classrooms

Catch the Perseids meteor shower!

Check out the 'fun' in fungi

Too hot to think? Studies shows heat affects your brain

Love NJ's outdoors? Take action now!

New Jersey's official reptile, the bog turtle

Sea level rise and New Jersey: Not perfect together

These New Jersey plants have an appetite for insects

Explore the Pine Barrens through paddles, hikes and tours

Like to jog? 'Plog' instead and keep NJ clean

Love Jersey fruit? Thank our native pollinators!

Good news for globally rare swamp pink lilies

Say cheese! Remote cameras aid wildlife research

Begone, single-use plastic bags!

3,000 birds and counting for 'bluebird grandfather'

The Pine Barrens gets some help from its friends

A clean energy future for New Jersey

Cowtown and rare grassland birds, perfect together

Fight light pollution during International Dark Sky Week

New film tells story of how Petty's Island was saved

Ten years of nipping invasive species in the bud

Welcome spring in a county park

Go for a walk and feel better!

Grab a friend and go outside

Recycle your way to zero waste!

Last call for winter wildlife watching on Jersey coast

Without its 'understory' layer, the forest will collapse

From whale songs to poetry, a remarkable journey

A cleaner, greener New Jersey

Let's keep New Jersey the Garden State, not the Pipeline State

New Jersey's winter hikes

'Trees don't vote' but Byrne saved Pine Barrens anyway

Governor-elect Murphy should set new course on the environment


December 2018
November 2018
October 2018
September 2018
August 2018
July 2018
June 2018
May 2018
April 2018
March 2018
February 2018
January 2018
December 2017
November 2017
October 2017
September 2017
August 2017
July 2017
June 2017
May 2017
April 2017
March 2017
February 2017
January 2017
December 2016
November 2016
October 2016
September 2016
August 2016
July 2016
June 2016
May 2016
April 2016
March 2016
February 2016
January 2016
December 2015
November 2015
October 2015
September 2015
August 2015
July 2015
June 2015
May 2015
April 2015
March 2015
February 2015
January 2015
December 2014
November 2014
October 2014
September 2014
August 2014
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011


New Jersey Conservation Foundation on FacebookNew Jersey Conservation Foundation on TwitterNew Jersey Conservation Foundation on FlickrNew Jersey Conservation Foundation YouTube ChannelShare      
New Jersey Conservation Foundation           Bamboo Brook, 170 Longview Road, Far Hills, NJ 07931           908-234-1225 
home  | nj statewide eventscontact us  |  sitemap  |  privacy policy  |  DONATE