Thursday, July 31, 2008
I set four camera traps in Sierra county a month before the camera trapping workshop, and was mighty pleased to find that mountain beavers -- hereinafter show'tls or aplodons -- occur in the drainages feeding the Yuba river.
Yes, from here on out I am calling them "aplodons" or "showtls". They deserve a catchy vernacular tag or a name (like "simple teeth") befitting their unique evolutionary position.
Let's forget the term "mountain beaver". Yes, like beavers they are excellent swimmers and waterway engineers, but there the resemblance ends. The name boomer doesn't cut it either. The only report of such a sound is now over 130 years old.
Then there's the name "sh'auch" used by the Indians of Puget Sound. It meant "creature that creeps in the undergrowth", and you can guess why that didn't take. The other moniker -- "sewellel" -- is said to have been the Indian term applied to robes made of their furs.
Enough. Back to the workshop. . .
When it commenced on July 21, the cams had been in the field for a month. Knowing that camera trapping is often slow business, I wanted to fire up the class at the outset by showing them the seldom seen showtl.
The gamble paid off. After I had rambled at length the first morning about camera trap sets and camera attachment methods, we climbed into the nearby thicket, found the cam, and clicked through the pictures.
A beady-eyed rodent finally appeared in the LCD, and being topless, she disclosed her sex within the first few pictures (notice that I don't confuse sex with gender). We didn't realize this until she was displayed on the computer screen.
The fact that she was bare-breasted has special significance. Female aplodons have very hairy nipples when cycling, pregnant, or lactating. We're talking about "dense patches of black hairs". Though a sign of showtl womanhood and of certain adaptiveness, it is not an enviable trait. It's likely that this bare-nippled girl was born this spring.
Aplodon colonies in this part of the sierra are in sprawling alder thickets bordering the Yuba river and its tributaries. We found numerous nipped twigs of alder, but the pruned stubs were dry and gray. I was almost convinced that alder is a springtime food until we found a burrow with leafy wilting branches.
Lewis and Clark were the first to report on aplodon's climbing ability, but University of California mammalogists Joseph Grinnell and Tracy Storer had their doubts. Lloyd Ingles proved it with photography.
Ingles built an enclosure at Huntington Lake in the southern sierra, and stocked it with two females from a nearby colony. They climbed 20 ft up into white firs and lodgepole pines, and in 4 weeks pruned off most of the branches. Aplodons are respectable if not acrobatic climbers of trees and shrubs, but they have to descend butt-first.
I thought that aplodons would be easy pickings for the workshop participants, but I was wrong. No one else got their photos.
When I checked the date and time stamps on my own pictures I realized why. The animal had visited the burrow only on three occasions, and the first visit wasn't until three weeks had passed. Aplodons have extensive burrow systems with multiple openings.
During the course I tried to get more photos by planting my small camera traps in underground tunnels with caved in ceilings. Every sign indicated they were active tunnels, but no aplodon showed it face.
Camp, C.L. 1918. Excavations of the burrows of the rodent Aplodontia, with observations on the habits of the animal. Universitu of California Publications in Zoology 17(18):517-536
Godin, A. J. 1964. A review of the literature on the monjtain beaver. Special Scientific Report -- Wildlife No. 78. U.S. Department of the Interior, Fish & Wildlife Service, Bureau of Sport Fisheries and Wildlife, Washington D.C.
Ingles, L.G. 1960. Tree climbing by mountain beavers. Journal of Mammalogy, 42(3):120-121
Scheffer, T.H. 1929. Mountain beavers in the Pacific Northwest: their habits, economic status, and control. US Department of Agriculture, Farmers' Bulletion No. 1598:1-18
Monday, July 28, 2008
Cute, isn't it?
Well, the codger's reaction is less adoration than amusement tinged with cynicism.
Here the log-perching Bambi is displaying the heart-warming curiosity of juvenile deer, a fetching trait that renders it highly attractive as fly bait. In fact, a number of mammals are known to be more vulnerable to parasitic fly infestation as juveniles than as adults.
Entomologist John R. Anderson wrote a fascinating paper about the infestation tactics of nose bot flies that parasitize black-tailed deer. (Unfortunately, I can no longer find the paper among 3000 uncatalogued reprints in the garage, so I am jogging my memory and give you the reference below).
You see deer and cattle share a very long history of relations with various species of bot flies that detect their hosts by very general (e.g. CO2 and urine) and very specific chemical signatures, such as volatile compounds from scent glands.
Out here in the west, two species of nose bot flies infest our black-tailed deer. How they zero in on their hosts isn't well known, but Anderson spent a lot of time watching parasitic flies dupe deer.
One species (Cephenemyia apicata), he found, takes advantage of the deer's curiosity.
The gravid fly chooses a bush in plain view of Bambi, and then buzzes about in a come-hither-come-yon dance. Bambi approaches to inspect this curious thing, and is rewarded with a tiny fly larva squirted onto it's moist muzzle. If the deer doesn't lick and swallow it, the larva wriggles into the nostrils.
Cephenemyia jellisoni, the other species, is a stealth hunter. It approaches the deer out-of-sight and from behind, and slowly moves forward beneath the soft underbelly. Then it quietly hovers into position under the animal's throat and muzzle, taking care to remain undetected by tracking the animal's head movements. When the time is right it dashes into position and squirts its larva ('larvaposits') on the moist lips or muzzle. Numerous females may attack a single deer.
The larvae settle in the pharyngeal pouches at the back of the throat, where they feed on tissue secretions and grow into beautiful bots. (I'm kidding of course.)
I still recall my revulsion the first time I saw nasal bots in the throat of a necropsied deer. We were having a wonderful time being young biologists, measuring testes, preserving uteri, while eating curried venison and drinking beer.
When we started to pull mandibles for aging, there they were at the back of the throat: a writhing mass of inch-long white maggots. We gagged and came close to tossing our cookies, but we were tough.
So I don't turn up my nose to insects. They are here to stay, and when nature pits Bambi against flies there's just not much of a contest.
Anderson JR. 1975. The behavior of nose bot flies (Cephenemyia apicata and C. jellisoni) when attacking black-tailed deer (Odocoileus hemionus columbianus) and the resulting reactions of the deer. Can J Zool., 53(7):977-92.
Anderson, JR. and & W Olkowski. 1968. Carbon Dioxide as an Attractant for Host-seeking Cephenemyia Females (Diptera: Oestridae). Nature, 220:190-191
Cogley, TP. 1987. Effects of Cephenemyia spp. (Diptera: Oestridae) on the nasopharynx of black-tailed deer (Odocoileus hemionus columbianus). Journal of Wildlife Diseases, 23(4):596-605
Olroyd, H. 1964. The natural history of flies. Weidenfeld and Nicholson, London
Tømmerås, BÅ., A. Wibe, AC. Nilssen, and JR Anderson. 1993. The olfactory response of the reindeer nose bot fly, Cephenemyia trompe (Oestridae), to components from interdigital pheromone gland and urine from the host reindeer, Rangifer tarandus. Chemoecology 4(2):115-119
Sunday, July 27, 2008
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.)
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
Wednesday, July 16, 2008
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.
Tuesday, July 15, 2008
Only one bobcat showed itself during the two months of our second session of camera trapping at the Cleary Reserve. This was the only picture, and it was the wrong side of the cat to compare with the earlier animal.
I suspect it stopped to sniff the scat between its hindlegs, which gave the camera enough time to power up and take the picture -- about 4-5 seconds.
Monday, July 14, 2008
The coons were back last night, and they encountered the cameras in new positions. For some reason this camera managed to offend the two kids.
What you see is a common mammalian threat display -- piloerection. They're all puffed up, they've arched their backs, and one is standing on its tippy toes trying to look bigger.
Real scary. If that camera could burp, they'd be falling over one another trying to get away.
Finally they backed down, and joined mom.
She showed them how to find hornet nests under the deck, but they were still a little spooky and acting tough.
Sunday, July 13, 2008
The pool coon was back with her two kids last night. The cameras started flashing at 11:00PM and ended this morning at 5:10. I missed the action, but not the redhead, whose awakening words were: "You got a lot of pictures last night".
Three cams were ready for the action. The three coons made 8 visits and left 67 images.
The pool intake is a big attraction. That's where the floating leaves and insects accumulate.
She's teaching them well,
and they act like they own the place.
Saturday, July 12, 2008
The redhead awakened me at 5:30 yesterday to announce the visitors. There in the smoke was one big and two little raccoons peering intently into the swimming pool. (Whur's the fish?)
I set a camera last night , and shortly after sunset the redhead called from the living room saying the camera just flashed.
I switched on the outside lights, and there she was -- Ma Coon staring suspiciously at the camera across the pool. Obviously, this was her first experience with the electronic flash.
What you see above is the best I can offer -- "raccoon pondering the deep waters". I am afraid the poolside menu offers only backswimmers and soggy insects. Unfortunately, the kids were a little bashful -- no pics of them. My firefighting equipment (pump and hoses) is in the background.
(Hey! Calfire lifted the evacuation orders today, and I also finished the camera trapping manual.)
Friday, July 11, 2008
A family of gray foxes gave us pictures at several cameras on the mountain.
The fellow cocking his leg above is probably the father, and below he is with his mate. I can't tell them apart. The one in the foreground is rubbing its neck on leaves of catmint.
Here is one of the parents with a pup (I think). Sniffing lips. The youngster looks to be about two thirds adult size.
And here are two pups resting on the same log. The coat has adult colors (washed out by the flash), but it's still a bit fluffy. The short muzzle gives them the puppy look.
Sunday, July 6, 2008
Rich and I met on the mountain the day before the 4th of July. There was no time for an overnighter, so we hit the trail a little before noon, and finished at 6:00.
The cams had been out for 2 months, and I was sure the batteries would be dead, but the auxiliary D cells were still going, though barely.
We collected the cams, so I would have some extras for the workshop, and replaced them with Rich's new cams.
The trail-scat set seen here is the most productive location. There were 144 exposures, and the puma was one of the new species. There were only two exposures, but both were full body images. The scat gets their attention long enough for the camera to power up and snap a picture -- about 3-4 seconds.
I'll post a few other shots of interest in the next few days.
Wednesday, July 2, 2008
You're damn right the codger's been quiet. The Humbolt fire, which started on June 11 was too close for comfort and a lot of good people lost their homes. We packed our bags the first day, and then sat around listening to the radio. The fire started on Doe Mill Ridge as seen above from our place. It crossed Butte Creek Canyon, climbed the next ridge, and swept through lower Paradise, the next town down the slope from us.
Hale and rain arrived 10 days later, but not enough to have an effect. Instead, a spot fire broke out under a power line about a mile away from home, and this is what we saw.
A spotter plane and a tanker showed up that afternoon, and 6 dumps of retardant put it out.
Bearing witness is a helpless feeling, and a lot of strange and foreboding thoughts flash through the mind, but your esteem of firefighters soars.
By Sunday the 22nd, it was time to get away. There was no call for evacuation in our neighborhood, it was just that the redhead was fretting so much. We drove 125 miles to the Sierra Nevada Field Campus to meet Jim Steele and put out some camera traps.
We passed a new fire that had just started in the lower Feather River Canyon, and just beyond Quincy we saw this. No, those are not clouds.
SF State's field campus was well beyond the lightning strikes. It was a lovely afternoon, and we set four camera traps.
I couldn't resist placing two in an alder thicket.
The signs of mountain beaver were everywhere.
One good thing has come out of the smoke and fire. I've been housebound and busy hammering out a camera trapping manual for the workshop in a couple weeks.