Coyote gets BT Jack

The coyote caught BT Jack in mid-June, and strolled past the camera 45 minutes before midnight.

BT Jack is the black-tailed jackrabbit; that's how I abbreviate the species in our data tabulations for the Chimineas Ranch.

A 5 lb jack rabbit is a decent meal for a 30 lb coyote, and this coyote seems to have already devoured nearly half of it.

Another coyote happened by but was less composed.

And the bobcat was a bit spooky, though it didn't depart till it had sniffed the bait under the rock.

Black-tail jack at the badger dig

7:09:12 AM

The scent of ripe mackerel lured Black-tailed jack to the badger dig.

That's my guess, because the lagomorph's appetite for protein is high when forage is coarse and low in protein.

When a doe rabbit eats her neonates, the husbandryman's advice it to feed her more protein.

Back to Jack.

Ever vigilant, he startled.

Then he returned to examine the burrow wherein the ensconced can emitted its bacterial bouquet.

 7:09:46AM

Looking puzzled, he paused.

7:09:58AM

And then disappeared into the gloamy light of a new day.

Poison Water guzzlers-thirsty bunnies

Desert cottontails and black-tailed jackrabbits were Poison Water regulars.  

Drinkers in the spring can not easily see approaching predators. 

Which makes you wonder how many have been stalked and caught by bobcats and coyotes while drinking behind the boards of the spring. 

Animal Psychology for Camera Trappers-Part 1

[A raised forefoot while immobile and staring often indicates uncertainty. This full-frame photo shows an alert young squirrel fixating the camera with hesitation. In the next frame it resumed eating sunflower seeds.]

Many animals are cautious or fearful of unfamiliar objects or situations. This healthy response to the unknown is called neophobia or “fear of the new”.  

I believe that neophobia was the reason my first camera trap pictures of gray fox were in the distance or half out of the frame. After a few weeks the animal(s) approached more closely, and finally became bold enough to examine the camera at close range. 

 

[A jackrabbit assumes a startled stance in reaction to the camera trap. The widely spaced rear feet indicates it is prepared to bolt.]

If there is bait near the camera you might read ambivalence in a neophobic animal’s body language. 

The attraction to the food is strong, but so is the hesitation to approach the strange object near by. The animal may stare at the camera, or stretch its body and creep forward as though it wants to approach and back off at the same time.

 

Or it may approach and sniff toward the camera, then circle and test the air from a different direction. These are manifestations of approach-avoidance conflict.

Caution wanes quickly when repeated exposure to a strange object proves harmless. Since there are neither positive nor negative consequences, the animal habituates to the stimulus.  

Habituation is why we don’t often see neophobic or avoidance–conflict reactions in camera trap photos. 

Also, habituation usually defeats the clever tinkerer who cooks up various repellents for garbage-can bears and bird-feeder squirrels. Fearful reactions wane, unless the repellent is painful or extremely disturbing . The animals habituate. 

[A jackrabbit in a normal resting stance in its form (nest).  The animal habituated to the camera which was staked closer to the nest on three successive nights while the animal was absent. The camera recorded its daily cycle of rest, grooming, and defecation for a week without apparent disturbance.]

"I'm all ears!"

When H. Ross Perot declared 'I'm all ears' early in the 1992 presidential campaign, he really meant he was listening intently. But the articulate entrepreneur was blessed with robust ears and his statement earned him belly laughs that Jerry Seinfeld would envy.

Now that we're talking ears, how many times have you wondered why rabbits have such long ones? I mean, when you are cruising along and see a roadkilled jackrabbit, or think about the energizer rabbit . . .do you knit your brows and ponder:

"Why? Why is it that they have such large ears? Is it all about good hearing, or is something else going on?"

What? The question has never crossed your mind? You've got to be kidding!

Well then, how about this: the antelope jackrabbit (L. alleni) of our American southwest has ears that are 25% of its body surface. On the other hand, the ears of the black-tailed jackrabbit that you see at my water trough make up 19% of its body surface. Still impressive structures.

Back in the late 1800s a naturalist named J.A. Allen, who spent a lot of time measuring museum specimens (including the ears of rabbits) had a revelation. He noticed that birds and mammals from cold climates have smaller extremities than their relatives from warmer climates. He had hit on a general principle of the natural world, and he wrote it up and published it. Thus we got Allen's Rule.

Since then biologists have spent countless years measuring more museum specimens, and have found Allen's Rule to be less comprehensive than Allen thought. It does not apply to all species, nor to all extremities (legs, tails, ears, noses, beaks). In cottontails and brush rabbits, for example, no extremities 'obey' the rule. But it does apply to the ears (and tails) of jackrabbits.

It makes sense, because the ears of rabbits are like automotive radiators. You need bigger radiators in hot climates. The difference is that jackrabbits have more sophisticated thermostats than cars, and thanks to the studies of Professor Richard Hill and his associates, here's how they work in a nutshell.

Jackrabbits crank down blood flow to their ears when they are resting at temperatures below 24 C (=75F). Under these conditions their ear temperatures are slightly above air temperature (from 0.3 to 2.5 degrees C). When it's freezing on the plains, jacks have chilly ears. That way they conserve body heat.

At warm temperatures (above 31C = 88F) the ears' arteries dilate, blood flow increases, and the ears shed body heat by convection and radiation.

But when jackrabbits are exercising, their body temperature increases just as it does in people. Of course, running jackrabbits pant and thus cool their snouts by evaporation, but their ears can become considerably warmer than the air, and they also vibrate, which to some extent can help shed body heat by convection. After 15 to 25 minutes of rest the ears have cooled off, and the rabbits are back to their resting body temperature of 38C (=100F).

What about when it gets really hot? When temperatures reach 45.5C (=114F) jacks rely on panting and evaporation to shed body heat. Most of the time the ears stay cooler than the air because body temperature is less than air temperature, and their blood flow is restricted. However, every several minutes the arteries engorge for 10 to 20 seconds, at which time they absorb heat from the air. This adds significantly to the animal's overall heat gain.

If you are trying to get rid of heat this seems counterproductive. So, why let those big ears absorb more heat? Why not minimize their blood circulation so this doesn't happen? The most logical answer is that hot ears have their own metabolic demands for oxygen, blood sugar, and waste removal.

If you like the car radiator analogy, think of it this way. You've got to flush your radiator if you want to keep it working.




References

Griffing, J.P. 1974. Body measurements of black-tailed jackrabbits of southeastern New Mexico with implications of Allen's Rule. Journal of Mammalogy, 55(3):674-678. [the temperature data in this paper were in error, as noted in Hill et al (1980)].

Hill, R.W. and J.H. Veghte. 1976. Jackrabbit ears: surface temperatures and vascular responses. Science, 194(4263):436-438.

Hill, R.W., D.P. Christian, and J.H. Veghte. 1980. Pinna temperature in exercising jackrabbits, Lepus californicus. Journal of Mammalogy, 61(1):30-38.

Hinds, D.S. 1977. Acclimatization of thermoregulation in desert-inhabiting jackrabbits (Lepus alleni and Lepus californicus). Ecology 58(2):246-264.

Stevenson, R.D. 1986. Allen's Rule in North American rabbits (Sylvilagus) and hares (Lepus) is an exception, not a rule. Journal of Mammalogy, 67(2):312-316.

The scent of the cat

The puma's lovefest on the rock didn't go unnoticed by three species that no doubt appear on the puma's menu. You saw the black bear sniffing the rock on the previous post. That was 26 hours after the puma's visit. Two more days passed, and then came the gray fox at 3:45 in the afternoon. It looks to me like his coat is bristling a bit -- the old autonomic response of pilo-erection. It could well be that just the scent of the cat made his hair stand up.



The next morning at 7:45 the jackrabbit hopped up on the rock and checked the scent too. In the past 6 months I've gotten perhaps a half dozen pictures of jackrabbits at this camera trap set, but this is the only rabbit that took its picture on the rock.

All of these mammals are sniffing the very same area where the cat rubbed it neck. I'd wager they're tuned in to an important cue -- a predator was here.

Bunny Behavior Pop-Quiz

You weren't expecting this, but it's time for a pop-quiz. (Beware, more than one answer may be correct.)

The jackrabbit in photo 1 (above) is:
a) urinating
b) a young adult
c) an aged adult
d) stretching its legs before a race




The jackrabbit in photo 2 is:
a) resting
b) hungry
c) startled
d) looking for a mate




The jackrabbit in photo 3 is:
a) beginning to leap forward
b) spraying urine on a female
c) resuming a normal posture after standing upright on the hindlegs
d) playing




The jackrabbit in photo 4 is probably:
a) suffering from shin splints of the forelegs
b) grazing
c) waking up from a bunny nap
d) cleaning its mouth on the damp grass




The jackrabbit in photo 5 is probably:
a) hopping intermittently
b) running quickly
c) walking
d) posing for the camera


ANSWERS

Photo 1
a) urinating (QUITE POSSIBLE)
b) a young adult (DEFINITELY)
c) an aged adult (WRONG. DEFINITELY NOT)
d) stretching its legs before a race (WRONG. UNLIKELY)
(The animal was born this spring, and is not quite adult size yet. It still has that skinny look.)

Photo 2
a) resting (WRONG)
b) hungry (WRONG. DOES IT LOOK HUNGRY TO YOU?)
c) startled (DEFINITELY)
d) looking for a mate (WRONG. ITS TOO SCARED TO BE THINKING ABOUT THAT)
(This stance has all the signs of a startled animal -- hindlegs spread, body crouched, and ears forward. The sound of the camera might have triggered the response.)

Photo 3
a) beginning to leap forward (POSSIBLY)
b) spraying urine on a female (WRONG. DO YOU SEE SOMETHING I DON'T SEE? TRY AGAIN)
c) resuming a normal posture after standing upright on the hindlegs (PROBABLY)
d) playing (WRONG)
(Jackrabbits stand upright (bipedally) when scoping out the neighborhood for danger. I think this animal is resuming its normal stance after standing upright. Urine spraying is also a courtship behavior seen in rabbits and some rodents, but that is NOT what you are seeing here.)

Photo 4
a) suffering from shin splints of the forelegs (WRONG)
b) grazing (CORRECT)
c) waking up from a bunny nap (WRONG)
d) cleaning its mouth on the damp grass (WRONG)
(Sometimes jackrabbits graze while kneeling on bent forelegs, just as warthogs do. The legs may look injured, but they aren't.)

Photo 5
a) hopping intermittently (DOUBTFUL)
b) running quickly (MOST PROBABLY)
c) walking (WRONG)
d) posing for the camera (WRONG)
(Looks to me like this animal is running (technically, galloping), but doesn't appear to running "full-speed ahead".

If you answered all the questions right, you have wasted a lot of time watching animals and you have a healthy dose of biophilia.
If you answered them all wrong, you were probably thinking this was about two-legged bunnies.
If you answered one or two correctly, you need to spend more time out-of-doors.

Macavity Cat

My first glimpse of Macavity was back in February. I was puttering around outside when I surprised a large tabby cat slipping under the deck. My best falsetto "Here kitty kitty kitty kitty kitty. . ." had no effect. Joy. A new stray was here to prey on birds at the feeder.

Two days later the same cat dashed out of the garage when I surprised it gulping chicken parts consigned to the garbage. I had left the door open for only a few minutes, but Macavity had been watching and made his move. This cat clearly knew far more about us than we knew about him. When I didn't see the cat for a couple of months I concluded it had moved on.

Then one day about three weeks ago I was putzing about the garden, and I kept smelling cat piss. Wherever I went I would suddenly catch a whiff. I was on hands and knees sniffing for a scent post when the redhead casually observed that a cat had urinated on the polar fleece I was wearing.
"Isn't that the polar fleece you left hanging outside for the past few days?" she asked.
(How come women are so perceptive?)
She was correct, of course, and offered to wash it right then and there.
My woodsy codger musk had offended the cat, and my wife advised me not to leave it hanging outside anymore.

A couple weeks passed before our next encounter with Macavity. My wife needed help in the garden. An unknown mammalian herbivore had started to nip buds off the plants. I assured her that the codger could solve the problem, first by identifying the offender, and then by prescribing appropriate measures in behavioral modification. I set a camera trap in the patio.

The only mammal photographed (above) was Macavity on his nightly beat, strolling down the garden path to the back gate, looking confident and in fine fettle. The herbivory ceased and the plants started to recover.

Finally, yesterday I went to the potting shed and noticed a trail of blood and rabbit hair on the ground. I followed the drag mark through the leaves to the water tank. In the narrow space beneath the platform was a dead fully-grown black-tailed jackrabbit.

I put a camera trap under the platform, and this morning found 6 photos. Macavity returned to his prey at 8:12 PM, and apparently fed for 25 minutes. In the last photo at 1:18 AM he had moved the carcass closer to the camera. In the morning there was no trace of it.

The felid body plan is a design for killing warm-blooded vertebrates, and even a house cat has the equipment to take down prey as large as itself.

Bean counting

Sometimes bean-counting is a necessity. In my former life as a science administrator my colleagues and I were required to count beans regularly. It started shortly after the new chief said he was going to get the scientists under control, and bean-counting became a job priority. We reported commonplace things that had been happening for years, and were reminded monthly to submit our reports to the bean-counting directorate. It was "busywork", and bean-counting became a critical factor in our annual performance evaluations.

Recently I drew upon my store of bean-counting expertise. A year and a half ago I had noticed small dusty patches near my house. I thought I had a problem -- erosion. Then I observed that each bare area had a few bunny beans mixed in the dirt. So I did what came naturally. I sorted the beans by age and counted them.



Two days later I returned and counted them again. The numbers had changed, and the fresh beans had increased in number! (The bean-counting directorate would have been pleased.)

Next, I set a camera trap. A week later I viewed the pictures and learned that the only visitors were black-tailed jackrabbits.



Each night one or more rabbits visited the bare patch, where they hung around and sniffed the ground for a few minutes at a time.



I didn’t get any pictures of the rabbits rolling around in the dust, so we can't call these places wallows. And so far I haven't found any references to jackrabbits counting beans.

As for the supreme bean counter back at the Smithsonian, a recent audit showed that he indulged in rather questionable bean-counting practices himself, and he decided to move on.

Spy pics from the rabbit's boudoir

The "spy camera" has been creeping closer and closer to jackrabbit's boudoir. Now 30 inches away, it gawks at her like a bold Peeping Tom. I got over 250 still pictures and 66 short movies last week, and she could care less. But I can only expect to find her in this boudoir every second or third day. Obviously she has several.

Here's what I learned. She arrives at her boudoir shortly after 6:00AM, but she doesn’t settle down right away. First she sits attentively with rabbit ears alert. Next, she cleans her hind feet as if they were $250 running shoes. This makes perfect sense, since hers have to last a lifetime, which in her case that would be another 3 years max. Then she washes her face, cleans her forefeet, and licks her breast, sides, and lower back.




She's a very clean animal, except for the business of eating the feces.

When that is about to happen, she gets a certain look, "Oh oh, . . . something's coming!" Then she bends to one side with the flexibility of a contortionist and receives the pasty contents of the caecum, which is a large appendix to the intestine. (View the following 4 photos as a clockwise sequence--they took place in 32 seconds).



If I am reading the photos correctly, the caecum evacuates its contents about every half hour or so, because that's how often she goes through the manuever.

Soft feces isn't the finished fecal product, but it isn't partially digested vegetation either. They reportedly have a protein content of 36% and a water content of 80%. Pelleted feces have 14% protein and 74% water. In rabbits, coprophagy seems to be a way of recycling protein that fails to be absorbed on the first passage through the intestine. In other words, it's a way of extracting maximum protein from food. Thus, rabbits were among the earliest recyclers.

I think it's time to end this post. I am hearing "Something's coming" from West Side Story, and I'm feeling poetic....

"Something's coming, something good,
proteinaceous caecal food, its time to eaaaaattttt!

Enough!

References

Best, T. 1996. Lepus californicus. Mammalian Species, No. 530:1-10.
Lechleitner, R.R. 1957. Reingestion in the black-tailed jackrabbit. Journal of Mammalogy, 38:481-485.

Jackrabbit hideout

A couple days ago I scared up a black-tailed jackrabbit. It was hiding in a rabbit-made depression (or form) under a live oak on a steep slope near the house. Resting nearby was another jack that joined it as it fled. I assume the female was the one in the form. When I returned with a camera trap an hour later she was back in the form. So I frightened her twice in the same day.

After that mistake, I checked the site with binoculars several times that day, but a day and a half passed before she returned to her form around 6:12AM. I got only 20 pictures over the next hour because the cam was using internal memory. I checked on her periodically during the day and found her hunkered down in the form. She had retreated to it after the cam stopped shooting

Rabbits have a peculiar nutritional habit of eating their own feces (its called refecation). I think she might be doing that in this photo. I'm leaving the cam in place, and with luck will have more to say in a few days.

Jackalope shed its horns

The jackalope rut must be over, because this buck is no longer wearing his headgear. He has that alarmed and bug-eyed look that many bucks get when they lose these weapons and status symbols that are so important for reproductive success in jackalope society.