Thanks for the note. I remember you, and the bat corpse! You probably do have big brown bats on the move during the winter. Unfortunately, it's due to loss of fat reserves due to WNS. I know that wildlife rehabbers in the state are getting ALOT more bats this year than in previous years. My guess is that the big brown bats are moving out of their hibernacula (caves, attics, etc.) to feed, and then using some old day roosts, like your bat box, for a day here and there. It's not surprising that you are finding scat. It's just too bad that they are using the bat box, as it's less climate controlled than their hibernacula options. At the same time, it's a better, safer option for them vs. more exposed options. There's nothing you need to do - the bats will move if they get too cold, and hopefully go back to their long-term resting areas. The less we disturb them, the better. We just keep our fingers crossed, and hope they can make it through this awfully cold, snowy time.
Karen E. (Francl) Powers, Ph.D.
Associate Professor, Biology
Radford, VA 24142
(540) 831-6537 (office); (540) 831-5129 (fax)
From: Ross Dennis [firstname.lastname@example.org]
Sent: Monday, February 23, 2015 4:51 PM
To: Powers, Karen
Subject: Big brown bats -- not migrating?
We have met several times at the Mt Rogers Naturalists’ Rally. Last spring I showed you a corpse of a bat which you identified as a Big Brown. A small colony (up to 15 individuals) spends summers in a ‘bat box’ under the eaves of my house near Floyd, VA. I take note of their approximate arrival and departure each year. This year they left around the end of October 2014. This is when I last saw them, and when I no longer need to sweep up their scat.
However, around December I began noting scat in smaller quantities but identical to what I normally see in summer. I have noted scat accumulating irregularly, but continuing throughout the winter to the present. Dis-aggregating the scat with a sharp needle suggests insect parts when viewed with a magnifying glass.
I have not seen any bats. I have avoided disturbing the bat box (i.e. climbing a ladder to open it up and look in). You have instructed me in how sensitive bats are to be disturbed during hibernation.
My questions: I did not think the Big Brown bat would ‘hibernate’ in its summer location.
Do bats defecate during hibernation?
Am I mistaking mouse droppings for bat droppings? There are none in the house where I would expect mice, and none except under the bat box.
Other than continued observation, is there anything that you recommend I do. I am glad to send you samples or show the bat box to you or one of your students.
Dennis Ross MD, PhD — retired professor of Pathology UNC
Male, hibernating in building
Accidentally trapped in garage.
Found lying dead (relatively fresh) in the bed of a pickup truck, Presumably fell from the ceiling of the barn vehicle is regularly parked in. Estimating about 3 inches in length based on width of my hand.
This is the first Big Brown bat detected at the La Brea Tar Pits. The species was identified using echolocation analysis software.
Encontré 2 individuos de Eptesicus fuscus y un individuo de Tadarida brasiliensis que se refugian juntos detrás de un cuadro colgado en el patio de una casa particular.
I found 2 individuals of Eptesicus fuscus and 1 individual of Tadarida brasiliensis who roost together behind a painting hung in the patio of a private home.
Encontré 3 individuos de Eptesicus fuscus que refugia detrás de un cuadro colgado en el patio de una casa particular.
I found 3 individuals of Eptesicus fuscus who roosts behind a painting hung in the patio of a private home.