Tetrapod Zoology

Red bats

i-111a622d80afde86f834e88a849cd5f2-Lasiurus borealis.jpg

Only time for a picture-of-the-day today, and this neat picture shows an Eastern red bat Lasiurus borealis, a mid-sized vesper bat (wingspan c. 300 mm) that occurs across most of eastern North America, some of northern South America, and parts of the Caribbean (in 2004 an individual was reported from north-east Alberta, which I presume is the northern-most record for this species). Eastern red bats are sexually dimorphic: females have grey frosting on their light brown fur while males are entirely red (this is a female). They are insectivorous, nomadic, migratory bats that roost individually in trees (though they will use cover right down at ground level). One particularly interesting thing they’ve been shown to do is eavesdrop on other red bats, and they’re attracted to the final buzzes that members of their own species make when closing in on insect prey.

This picture was staged: the bat was collected from sleep during fieldwork and has been hung up on the tree for the photo. I really like the image for a few reasons. Firstly, the pretty colours on L. borealis help to emphasise the point that bats aren’t all dark brown, grey or blackish. Secondly, the bat looks freaky weird: sort of like a little winged sloth. I also really like what it’s doing with its patagium and third finger. Thirdly, the bat looks cute. The photo was taken during fieldwork by ace biologist Anne-Marie of the excellent Pondering Pikaia, and is used with her permission.

On that note, I’m going away again. I’m going to leave the comments open again, so have fun until I’m back. Bye!


  1. #1 Jerzy or Jurek
    November 30, 2007

    Cool! please write more about bats social life – there are apparently lekking bats, group-hunting bats etc.

    A propos color – do you have a good image of Kerivoula picta, said to be most colorful bat?

  2. #2 Zach Miller
    November 30, 2007

    Hey, there you go! Maybe bats ‘n’ sloths share a common ancestor! Haha! I am SO blogging about this ridiculous idea.

  3. #3 Laelaps
    November 30, 2007

    Mmmm… tomato bat…

  4. #4 Noni Mausa
    November 30, 2007

    A quick Google pulled up this:


    Wow! I never imagined a bat this gaudy.

    Now we chould start outcrossing them with marmosets…


  5. #5 Anne-Marie
    November 30, 2007

    Thanks for the link and for mentioning the picture! Just wanted to note, although I did place the bat on the branch for the picture, this is a forest species, which means it IS indeed a tree rooster. They don’t hang from branches when they roost, however, they slip underneath bark, or sometimes even just settle in under leaf litter. So if you ever see a photo of one on a branch (like this one!), you can be reasonably sure that it was probably a set-up. 😉

  6. #6 Matt Mullenix
    November 30, 2007

    I once watched a friend’s female merlin (Falco columbarius) chase a red bat in northern Florida above a wooded edge at dusk. She caught the bat and spent the rest of the night out eating it. When we recovered her the next morning, she cast up a red pellet.

  7. #7 JW Tan
    December 1, 2007

    Ooh, if you’re taking requests Darren, could I make one for a post on bat evolution and available fossil evidence?

    Cheeky I know.

  8. #8 Jerzy or Jurek
    December 1, 2007

    BTW, I would never touch any animal behaving like this bat out of fear that it has something contagious (e.g. final stage of rabies).

    @Matt Mullenix
    That’s why bats are nocturnal – their sonar only works short distance and forwards, so birds have easy time catching them!

  9. #9 deang
    December 1, 2007

    Cool picture! At this link, there’s a picture of one from central Texas roosting in a Texas Buckeye tree:


    Beautiful creature.

  10. #10 Tengu
    December 1, 2007

    Id like to see something on bat evolution too.

  11. #11 arachnophile
    December 2, 2007

    @Matt Mullenix: Amazing story! Merlins are my all-time favourite raptor, hands down, and I’ve worked with many (existent varieties of course). I always tell people that if they were the size of eagles, no one would be safe. 😉 Them and GH owls.

    That is one beauty bat! I’ve always been partial to redheads myself. 😉

    As for future topics, I loved your discussion of Mark Witton’s work on pterosaur mass and flight capabilities (his paper – awesome). I don’t know if this has even been looked into or not but I always thought that looking at bats, even though they are mammals, would be a better analog. At least bats fly with membranes vs. feathers. I know that in almost every other way they are quite different but in terms of simple mass vs. lift, I’m just really curious. For all I know, it’s been done to death and thrown out already. 😉

    Is there some room for discussion about at least the differences in how we thing pterosaurs flew vs. our bat-friends?

  12. #12 Billy (A Liberal Disabled Vet)
    December 5, 2007

    I was down in florida over Thanksgiving and we visited Leu Gardens just north of Orlando. Wonderful cycad collection there. Anyway, we were looking at the cycads (and wondering about how long they would survive in Northeast Pennsylvania (it is currently 25 deg and snowing)) when my wife said, hey, that’s a bat. There was a small (6-8cm) reddish brown fuzzball snuggled into the longitudinal depression of a palm leaf. I said, no, bats are black/dark brown.

    I tried to get a photo, but my $%^^##*% camera kept focusing on an intervening branch. But know I know (thanks to you) that I was looking at an Eastern red bat. Damn. My wife was right. Again.

  13. #13 thylacine
    December 5, 2007

    I love this blog, but why is it that whenever fascinating dinosaur news breaks out and I look to this page for erudite comentary there is always a breathless update on the vinegar tited bat of lower east Cornwall, or some such creature.

    Is there some subtle British humour that I am missing? As an innocent American Hilbilly I always feel left out of these things. Just asking, Really old chap.

  14. #14 arachnophile
    December 6, 2007

    One thing I appreciate about this site is that the posts are very informed and come from genuine experience and knowledge, rather than whatever’s hot in “science news,” right at the moment. It’s so easy to fall into “hype headlines.” I think something entirely different is going on here, which is a good thing. I hope. 😉

    That being said, LOVE you ‘name’ thylacine 😀 Seriously, that’s one of my favourite animals, ever (so far discovered) ;). I’m a bit of an Aus/NZ-phile (lol).

    Are you looking for insight into the whole dino-mummy thing? Me too. *sigh*

  15. #15 Nathan Myers
    December 6, 2007

    Darren doesn’t get to write about anything current because he knows too much and is under embargo until the papers come out. We are obliged to content ourselves with galloping frogs and terror pigeons. And content we are!

    (Galloping terror pigeons?)

  16. #16 arachnophile
    December 6, 2007


    Come on Nathan! This is happening just when I was working up the “mojo,” to ask if the academics who haunt these halls knew of a site that had a paper associated with this discovery. Silly me, I thought that academia had dibs on the story. *lol* kidding

    I am so naive… ;p Evidently National Geographic funds anything even remotely cool – giving them ‘dibs’ on the story. UGH!

  17. #17 thylacine
    December 7, 2007

    Thanks for pointing all this out. Having spent years in publishing I should have figured this out for myself. I am so frustrated at the lack of real news about both Leonardo and Dakota.

    There is a big gap in Dinosurian literature between the material designed for children and that for the non anatomist enthusiast like myself. I do enjoy the many stories about grey tufted squirrel badgers though. One of my favorite daily reads.

  18. #18 arachnophile
    December 8, 2007

    I hear ya Thylacine. I’m in the same boat, really. I know more than SOME 8 yr olds but I’m also struggling to get information that’s up-to-date that isn’t written in paleo-speak (which I’m trying to teach myself). Am I a wannabe academic – certainly! 😉

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