Bats still flying and foraging

[MUD]

Hey all! I saw two bats last night at dusk flying around and diving for bugs! It was about 60 degrees here yesterday and warm again today. I guess they don't hibernate if it's too warm? They appeared to be big browns...at least by their size. This is the first time I recall seeing bats feeding in the winter. Any thoughts from the bat biologists?

[Komebeaux]

I am no bat biologist, but I do know that it is pretty common sometimes for bats to emerge on warmer days in the winter to forage.

[Ralph E. Powers]

Aye, a recent trip to Camp's Gulf cave revealed a number of bats in various stages of activity; between hibernation, plain sleep, flying around and moving about. It was fairly cool/warm that evening when we exited the cave.
I guess it depends upon the individual bat.

[Teresa]

It does make one wonder how warmer winters (if indeed we are going to a warmer climate) will affect not only bats, but bears, frogs, turtles, and other creatures who are accustomed to going torpid, semi-torpid or otherwise 'hibernate' in the winter.

All bats do not go into the same extent of hibernation. The only ones who achieve true hibernation are ones like pippistrelles, often encountered in winter caves only a few degrees warmer than the rock itself, and beaded with water. Even colonial myotis bats rouse occasionally. Some like the big browns, actually have more of a 'big sleep' similar to bears, where they get up and go out for a look see. Since many bat species mate during the early winter, the temperature changes and rousing may affect the later fertilization rates of the females.

[Ralph E. Powers]

It does make one wonder how warmer winters (if indeed we are going to a warmer climate) will affect not only bats, but bears, frogs, turtles, and other creatures who are accustomed to going torpid, semi-torpid or otherwise 'hibernate' in the winter.

All bats do not go into the same extent of hibernation. The only ones who achieve true hibernation are ones like pippistrelles, often encountered in winter caves only a few degrees warmer than the rock itself, and beaded with water. Even colonial myotis bats rouse occasionally. Some like the big browns, actually have more of a 'big sleep' similar to bears, where they get up and go out for a look see. Since many bat species mate during the early winter, the temperature changes and rousing may affect the later fertilization rates of the females.

While I'm not very good at quickly identifying individual species of bats the ones I saw in Camp's Gulf were probably a mix of Pips and Indiana Greys and Little Browns.
I had the unique pleasure of watching one groom itself while I was a few feet away. Obviously it wasn't bothered by my presence nor my light (halo... not direct beam) shining on it. There was another one asleep about a inch away from it.
Another one I saw was when David and I were climbing down from one of the big rooms and it was crawling over the rocks. THAT was really neat to watch. It's movement over the rocks was really something to see. Then it cornered it self... I backed up a little ways to give it room and it gave a little hop and flew off. Wish I had a camera.
Any and all bats that we saw in this (HUGE) cave we left well enough alone, except to snap a few photos.

I miss seeing the Townsend long/big eared bats in Utah but these pips and browns are just as wonderful.

[tropicalbats]

Hey all! I saw two bats last night at dusk flying around and diving for bugs! It was about 60 degrees here yesterday and warm again today. I guess they don't hibernate if it's too warm? They appeared to be big browns...at least by their size. This is the first time I recall seeing bats feeding in the winter. Any thoughts from the bat biologists?

Almost certainly you are seeing big browns. Most big browns do not seem to hibernate in caves, and are amazingly hardy animals. When it is warm enough out to find something to eat, they seem to prefer to eat. But other than anecdotal evidence, of which there is an abundance, I don't have any particular research on the topic.

But to try and keep such things out of the winter hibernacula numbers, in general cave surveys are done starting around early/mid January, to try and make sure that at least one good cold snap has put to bed most any and all bats that will use a particular cave for the winter. This standardizes things, making the surveys more useful, but doesn't address your question so well.

Sorry not to be more useful on this one.

Keith

[Cheryl Jones]

Warm weather waking bats
Sat, January 6, 2007
By CP
London (UK) Free Press

REGINA -- The warm winter weather is driving them a little batty.

Mark Brigham, a University of Regina biology professor, says there's been a higher than usual number of bat encounters lately.

Normally, they're hibernating at this time of year but with the rising temperature and a decrease in humidity, the bats have awakened.

"Just before Christmas, we had a flurry of calls when it went from cold to warm," said Brigham. "The bats have chosen places that don't stay cold enough and they lose all their fat reserves and they have to come out and find something to eat or die."

Brigham is the go-to guy when the bats wake up; he often gets calls to remove bats from buildings. So far this winter, Brigham said he has retrieved 15 to 20 bats from inside buildings.

Ideally, bats prefer a winter temperature of about plus two and high levels of humidity.
http://lfpress.ca/newsstand/News/Nation ... 8-sun.html