Face Book Face

Here's a real life caricature of a yearling white-tail.

It's a camera trap shot taken in West Virginia by my good friend and native Montanan Carl Hansen.

Carl's a photographer, and he used to travel with me in SE Asia.

He documented our field work with excellent photos, especially candid photos.

He took a lot of pictures of me running around with an insect net.

In my less active moments his pictures showed me looking a bit like this deer.

Being playfully inclined, I decided to photograph Carl's activities.

He was fond of wearing rather unusual field garb, and that would have sufficed.

But those pictures were already on the internet.

So I settled for taking pictures of him only when he was sleeping in broad daylight.

In truth, we all slept in broad daylight. It was hard to sleep at night in a pool of sweat under an insect net.

Yea verily we cat-napped by day. We nodded off to jet lag, trains lulled us into dreamy slumber, and heavy rice and curry lunches knocked us out.

But I staved off Morpheus longer than Carl, and got the pictures.

He never knew it till we got home and the film was developed.

Those were good times.

And we're still good friends, or he wouldn't have sent me this photo.

Carl's going to retire in just a few days.

HAPPY RETIREMENT, buddy.

Deer, flies, bats and phlebotomy

Chuck Gackstetter, a year-round camera trapper from southwest Minnesota was good enough to send me this amazing image. It was taken with his home-brewed camera trap, a Sony P41 with a Snapshot Sniper control board in a camouflaged Pelican case. (Thanks again, Chuck.)

Most of the insects look like mosquitoes, but the lighter-colored ones may be deer flies. (Entomologists please weigh in).

If that doe was running from the insects, she's didn't seem to be shaking them off.

A picture like this makes you wonder how much blood a deer loses to mosquitoes. I recall reading long ago that arctic mosquitoes could actually kill a caribou. It sounds a bit far fetched.

Mossies can double their body weight after a blood meal, and the mossie known as Culex pipiens pallens sucks as much as 7.1 milligrams of human blood at a time. Thus, a thousand mossies could siphon off about 7 grams of blood, or a quarter ounce. That doesn't sound lethal. It would take a lot more than that to drain a deer to the point of death, but I am not going to claim it is impossible.

So what about Minnesota's deer gleaning bats -- the ones presumbly feeding on blood filled mosquitoes? Up there in northern Minnesoata, Willy4003 posted yet another picture of a bat and deer. (You may have to register with Pixcontroller to see it-- not to worry, it's free.)

It's known that mosquitoes (Anopheles gambiae, to be exact) fly more slowly when carrying larger blood meals than mossies with smaller payloads. They are also more vulnerable to predation by jumping spiders.

And bats? It seems likely that insectivorous bats can discriminate blood-fattened from light-weight mossies using sonar, and may also find the fat slow ones to be easier pickings.

Is this the route that led to phlebotomist bats? If eating blood-sucking insects gave ancestral vampires a taste for blood, how did they make the transition to biting the insect's prey?

The most likely explanation is that they started to feed on insects that were in the act of drawing blood themselves. If so, it seems more likely that the parasite was not a mosquito, but a biting fly like a tabanid. (Blood sucking leeches seem far less likely candidates).

Why? Because biting flies leave bloody wounds. Mosquitoes are better phlebotomists. They don't leave a trace of blood unless crushed on the spot. Bat eats blood-bloated fly . . . bat licks bloody wound . . . bat nips skin . . . bat becomes vampire. That might have been the evolutionary scenario in deep time.

PS: I would have liked to consult the literature on this topic, and apologize for arm chair theorizing. I realize that another route to vampyry is for a bat specializing on small mammal prey (like Megaderma spp) to switch to increasingly larger prey. If any readers can refer me to relevant references on this, please let me know. I'll chase down the refs next time I am in the bay area.)


References

Bekku, Hisao. 19__?. On the amount of blood taken up by a female mosquito of Culex pipiens pallens Coquillett, Nagasaki Iggakai Zassi, XXVIII(9):1036-7

Roitberg, Bernard D., Mondor, Edward B., and Tyerman, Jabus G. A. 2003. Pouncing spider, flying mosquito: blood acquisition increases predation risk in mosquitoes. Behavioral Ecology, 14(5): 736-740

Minnesota's deer-gleaning bats

Are insectivorous bats attracted to mosquitoes attracted to deer? Apparently they are.



Willy4003, a serious recreational camera trapper from Floodwood, Minnesota got me to thinking about this when he posted recent photos of bats and deer on the Pixcontroller Forums, and he kindly gave me permission to post them here.

Willy's cam was set at "an established mineral lick surrounded by ash and spruce near a marshy lowlying area, hence the extensive mosquito population." His photos were taken between 9:28pm and 12:18am on June 16th, and July 6th and 7th.

I put the question to my old mammalogist buddy Don Wilson, who is a bat aficionado of the first order. He responded: "I haven't ever heard of anything like that. Seems especially unusual in Minnesota, where the species diversity of bats is low, and foliage gleaners are not at all common. Very interesting."

The term "foliage gleaner" (not yet in Wiktionary) refers to birds, bats, and insects that forage for insects in vegetation by hovering, swooping, darting, and diving at their prey.

Deer are powerful mosquito bait, and they also play into the life cycle of a number of other dipteran (fly) parasites, like nasal and skin bots. Biting flies and mosquitoes couldn't ask for a better host than a deer in summer, when the thin coat renders most of the body vulnerable to blood-suckers. This cropped photo shows the mossies tanking up, and judging from the red spots, this doe probably has an itchy udder.



Of course, the bat-deer association could just be a coincidence. The bat might have just been flying by. But I have the feeling that if camera trappers had faster cameras, there might get a lot more pictures of bats and deer.



It goes to show, there's still plenty of natural history to be learned, and camera traps are a good way to do it. A hat tip to Willy 4003 for sharing this neat finding.

Unexpected lady with a scar

Sometimes you get "species y", when you are targeting "species x".

I haven't seen a ringtail since the winter, but when I found this outcrop on a very steep slope I heard a voice saying, "Bassariscus astutus . . . Bassariscus astutus" (That's the scientific name for the ringtail). It's that time of year when little ringtails should be accompanying their moms, just like spotted skunklets. That's what I was hoping for.

Even though I used castoreum and cooked egg yolk, the ringtails didn't show, but there were plenty of shots of wood rats, deer mice, Steller jays and spotted skunks. And I got two pictures of this puma. She came on July 4th at 8:03 AM.

The camera was too close for a full length body shot, but this is the sharpest puma shot I have taken. You can count her whiskers.

What? You say you can't count her whiskers? Well, tell me this. Do you see a dark marking on the inside of the hind leg, just below the belly? I think it's a battle scar, a scrape that is almost healed. If I am right, my next guess is that it was inflicted by a struggling black-tailed deer.

Okay, I can hear the comments ("Where does he comes up with that crap?")

Well, let me ask you this. Have you ever tried to wrestle an adult deer to the ground?

My colleague Jim Dietz and I used to take turns wrestling white-tailed deer caught in a clover trap. This wasn't for recreation or exercise. We were capturing, marking and releasing deer so we could estimate population size.

We didn't have a collapsible clover trap that allowed us to topple the deer. Ours had a rigid frame, so we had to go into the trap WITH the deer.

This required the psychological preparation and concentration that you see in bronco riders before the gate swings open.
You pull your cap down to your ears, punch yourself, and blink hard. Then you take a deep breath ("the signal"), and your buddy pulls the door up so you can dive into the trap and get beat up.

The proper technique was to kind of mount the deer very quickly and bear down with your weight, so it collapsed beneath you with its hind legs extended. Then your buddy joined you, and threw a bag over the deer's head, which had a calming effect. We restrained them only briefly to take a few measurements. Then we pulled an identification collar over their necks. and released them. It was over.

The mental preparation didn't seem to make much difference, because the bedlam in the trap was in high-speed animation. You never forget the piston-power of those hindlegs. They tear your jeans, hoof-strafe your body, and kick the snot out of you. Though we were relatively young, neither of us ever cried, "Crikey mate! I wish I could do THAT again!"

With practice the puma dispatches the black-tailed deer and only gets a little roughed up. But every now and then it probably takes a hoof to the body, and that's what I think happened to this lady cat.