Bat House Forum

[bohningr]

All:

I've read old posts here... people have said, "I've got bachelor bats" or, "I've got a nursery colony", etc.

How do you know? How do you know if the bats in one's bathouse are a nursery colony or bachelor bats?


Rick

[cloudman75]

I can tell a nursery colony because they have pups at my location in June. From what I have read over the years, males, in general, do not roost with pregnant females . I write on the calendar each year the first day I see a pup. I save the calendars for reference. I have no way of identifying a batchelor for sure from a distance. I cannot answer how those who made a post on batchelors could identify them unless they made a close examination. From my experience, I believe
any number larger than 12 little brown bats who roost together in spring in a bathouse would be a nursery colony. If they have pups then it is confirmed. I don't know about other species. Happy batting to you. My nursery colony is here and in two bat houses on poles.I had a few pups last year on June 2. I could see them after the adults left to feed. Also I can see
a few mothers having a hard time getting up to speed on exit. This indicates to me they are flying with pups. When I see that, I shine a light up into the house to see if there are pups left behind while the mother feeds.

Frank

[Terry Lobdell]

My best guess is a bat roosting alone is a bachelor. Any bats roosting tight together are females. Sometimes I have a pair roosting tight together. I see this a lot in May. Because these pairs seem to disappear by June, it leads me to believe they are females and join the larger colony to give birth. Also, late in May the females seem to investigate all the bat houses choosing one to give birth in during June. By June I have only large groups of females or solitary roosting bats (bachelors) scattered throughout most of my bat houses.

[AlienSpy]

RE: How do you know?

I'd like to add to the good How Do You Know question, how do you know for the species of bats you have? Everyone seems so confident as to which species they have. Here in NE Georgia I've had 100 to 250 bats for 5 years that i watch almost every day and the only one i ever gat a positive id on was a dead one. Now, all the other bats, which seem to be an entire range of sizes, may be any thing but evening bats. the evening bat i ID'd is dead!

I can see there are no freetails but anything past that would simply be a guess. size is not a good id tool as even among individuals within the same species, size varies.

[cloudman75]

I have had some bats with my little browns that are smaller. How did you identify the evening bat? I have suspected
that I have some evening bats but cannot view them up close. I was able to view the little browns in my attic louver from a few inches away. I took photos then compared the photos with those on the net along with the size, etc. That's how I identified the little browns. I had three big browns this year. They are easy to spot since they are so large. I shine a light up in the house to check on pups. I also have a very close up photo of the little browns on the landing pad of the house when they got too hot to stay in the house.I am in Lithia Springs.

Frank

[Erik]

In this post I gave some advice on how to take pictures of bats inside the bat house. It can be useful for identification purposes.
When you are not sure about the species in your bat house: Take a picture during the day (when the bats are asleep or not very active) and put in on this forum.
Your fellow bat house builders and bat researchers are happy to give it a shot!
Having bats in your bat house is great for you and for those bats. Knowing the species makes it possible to contribute to distribution information on the species. And that can be very important for understanding the ecology of the species and for local, regional and national conservation efforts for the species.

Erik

[Joe Spencer]

All:

I've read old posts here... people have said, "I've got bachelor bats" or, "I've got a nursery colony", etc.

How do you know? How do you know if the bats in one's bathouse are a nursery colony or bachelor bats?

Rick

Males are frequently solitary and bachelor colony #'s are far less, usually <20 with nursery colonies being greater. I had a bachelor coloney of between 16-18 bats for two years and their numbers did not change during the birthing season. No young were born. The numbers also depend on the species. Little brown nursery colonies are larger than big brown nursery colonies as an example. Additionally, on average, females arrive earlier from hibernation than males as they need to rear young quickly. Of course this only refers to hibernating bats and not those which are active far longer in southern climates such as freetails.