Snake encounters

Lots of snake activity today, but no good photos.
This morning my dogs reacted to a loud keening noise and stormed to the side of the yard where our fire wood is stacked. I heard the buzz of a retreating rattler and found a dying packrat. Cody and Frodo were so excited that I had to pull them away. I wanted to watch the rattler come back to its prey, but I got distracted until I heard Frodo bark again. I arrived to see the rat, pulled along by the snake, disappear under the wood pile. The snake, probably a Diamondback Rattler, had moved into the packrat's nest. The packrats themselves are very disruptive neighbors, so we will try to let the snake stay and hope nobody gets bitten except the rats.

Gopher Snake tracks

Crossing the dirt road to visit our neighbors, we found the tracks of a big Gopher Snake that had crawled into a squirrel hole. This snake must be huge and heavy judging from the deep undulating imprints. (Diamondbacks move in a much straighter line)

 In the late afternoon I took the dogs on a walk into the state land next to our property. This should have been the first 100F day of the season, but the sky was slightly overcast and it never got quite so hot. Zebra Tail Lizards were hiding under a thin layer of sand and kept jumping out right under the dogs noses. The dogs are getting old and experienced by now, and Cody has pretty much abandoned the chase. He used to be so intend that he'd jerk the leash from my hand and jump right over the creosote bushes. Young Jackrabbits were zigzagging between the shrubs, taking Laika and Frodo with them in break-neck pursuit.

Sidewinder Rattlesnake, Photo by the late Young Cage

Suddenly there was a quick motion in the sand, and both Cody and Bilbo tore towards it. I heard the buzz from a small rattle. A small, light colored snake was launching itself backwards, nearly flying over the sand. Only the head seemed to stand still, focusing slit-pupiled eyes on me. And there was a little horn over each eye - a Sidewinder, my very first! I got no photo because the dogs were misbehaving and getting much too close. They seemed to know that this was no Diamondback. The snake headed backwards straight to a hole in the ground and disappeared.
Picture Rocks is at the eastern border of the distribution of this sand-loving species. I know that they have been found in Red Rock and along the Santa Cruz River bed.
This is the 4th species of rattlers in our direct vicinity. Diamondbacks are the most common, followed by the occasional Mojave and so far a single Tiger Rattlesnake in our wash, and now this Sidewinder.

I have been watching more and more Desert Iguanas over the last years, while the numbers of Ornate Tree Lizards and Spiny Magisters seem to be declining sharply. It is a if the warming climate and the prolonged drought are pushing western species from the infamously hot Yuma Dunes deep into our area.

Bird Pointers

Artistic freedom: the ptarmigan covey is flushed. A good bird dog would NOT do that, he'd just freeze on point

In the late eighties I studied circulatory adaptations in the brood patch of Ptarmigan in Norway. To find these secretive birds, I often relied on the sensitive noses and natural pointing instinct of bird dogs. Every family in Trondheim seemed to own a couple of Setters or Pointers.

Pointing Gambel's Quail family click for better video quality

To my surprise, I recently observed very similar pointing behavior not in dogs, but in Gambel's Quail. Coincidentally, these birds are close relatives of the northern Ptarmigan. Both species are galliformes,  chicken like ground dwellers with short wings, strong running legs, and strong family bonds that outlast the breeding season so you find them all year round in their typical coveys.

This morning I watched a couple with two fairly grown chicks at the feeding station in front of my studio window. They were long and thin with excitement, their necks stretched and their beaks pointing. They held this pose and focused on a spot on the ground that from my view point was obscured by a rock and an agave. Clearly the chicks were learning to fine tune their maybe instinctive pointing by this concerted effort. In social animals, learning and memory are facilitated by highly-emotional situations. These chicks were learning their lesson well.
But what was triggering the excitement? Different from most bird mobs these guys were quiet and the other bird species were not drawn into the melee. The Mourning Dove seems hardly interested, the Thrasher keeps eating, only a sparrow seems ready to chime in.

Diamondback Rattler

But I got up from my desk and got my snake stick knowing exactly what was hiding under the agave. A Diamondback Rattler was tightly curled, absorbing heat from the warm sand and the morning sun. It is now so hot during the day that he is most likely night-active. The feeding station is visited at night by rodents, so this is a popular spot for rattlers.

This one was a small guy and his rattle didn't make any sounds. The small ones tend to wander straight west from that location, right into our dog run. So we decided to move him several hundred meters north. When he resumes his journey next night, he will hopefully bypass our house and the dog beds.

Western Diamondbacks' mating attempt in fall

October 16, 2010
In front of my studio window, we have a little 'house' that protects one of our quail blocks from being carried off by coyotes or dogs - havelinas can't get through the backyard fence. This morning there were coils moving inside.

At first, we couldn't quite make heads or tails of it - there were too many loops. Then we saw the head tapping the back in an unusual motion, tenderly?.

Ok, two tails, and intertwined in a suggestive position. They mate in October? Normal mating season is in spring, I saw them in April. Fall matings do occur, though. In that case, the sperm will be retained viable by the female until spring, resulting in birth in next years warmer season. Interesting, but right under my window? in the dog run? Sorry, but we asked them to move.
Free transport provided - into the State Land next door. Yes, they can come back, but if they don't, others will. There's no vacuum in nature.

Pretty angry at first. Who wouldn't be. But we picked a nice place for theme in a dry wash with lots of rodent holes.


They took off together. I hope we didn't spoil their mood.

Squirrel's Revenge?

As a biologist, I deeply dislike anthropomorphic interpretations of animal behavior. To me it's far more intriguing to try to understand animal behavior in its own context.
Here are some interesting interactions between prey species and predator.

'Herpers' who feed live rodents to snakes can attest to the fearless indifference of many store-bought rats and mice towards snakes. In contrast, wild, experienced rodents seem to be anything but indifferent towards rattlers. But terror and caution are not the only reactions.
I once observed Round-tailed Ground Squirrel running up to a rattler that was sliding towards the squirrels burrow. The agitated rodent (tail flicking and vocalizing) approached the snake several times and came within easy striking distance. The snake ignored him and determinedly slithered into the burrow entrance, leaving the fussing squirrel behind.




Today, loud mobbing calls came from the ground feeder for birds in front of my window. Quail were pointing with greatly elongated necks. Thrashers were fanning their tails and Doves were lifting their wings menacingly. All the birds were apprehensive and jumpy, but stayed in striking distance - of a Diamond-backed Rattlesnake.





The snake ignored them, crawled into the cool shade by the bird bath and settled to stay. Its eyes were filmed over and blue - it may have been pre-occupied with molting.






But it was now inside our dog-run and very close to our patio. So with my snake stick, I moved him into a container and carried him about half a mile away from the house. His tail markings told me that he's an old acquaintance - I'd carried him away before.



When released, he took off quickly. May he stay away this time.








When I returned to my window seat there was another commotion. I had dropped the green snake stick where I caught the snake. Now a Harris' Antelope Squirrel was sniffing intently the tip of the stick. The snake end. The end that scares my dogs as much as a live rattler. The end that even smells of snake to my insensitive hay-fever impaired nose.












The squirrel then crawled around where the snake had been coiled. Followed the still visible tracks. Laid in the sand where the snake had rested. Came back to the snake end of the stick at least four times, sniffing, tail flicking excitedly, and ignoring my camera. (These guys are not tame and usually rather unapproachable.)







Then - finally - he jumped the noose end of the stick and started kicking, clawing and biting it. Leaving his toothmarks all over it (click to enlarge).

What the???

Rare encounter: A Mojave Rattler

We live in the Bajada of the west side of the Tucson Mountains. Yesterday morning my husband Randy, our dog Cody, and I went to the eastern part of our property to check out the blooming chollas. A Desert Iguana Dipsosaurus dorsalis was bobbing his head in a territorial display. They aren't very common here and I'd found one of them dead this spring, so we were very happy to see this one.

Then the short dry grass right behind the big lizard moved and a snake slithered by, not two feet from him. The very straight movement identified it as a rattler, other snakes move in a more undulating manner. Where lacy Creosote shadows and its own markings made it nearly invisible, it flattened itself to the ground. Snakes, who have no sternum, actually spread their ribs to do so. This pose allows them to absorb a maximum amount of heat from the warm sand and from the radiation of the sun. It eliminates most of the cast shadow which hides the snake even better.
This snake turned out to be a female Mojave Rattler, Crotalus scutulatus. Thanks, Brendan O'Connor, for verifying my identification which was based only on the wide white /narrow dark bands of the tail. More reliable diagnostic markers are the facial scales and the band that runs from the eyes to the corners of the mouth. I didn't want to get close enough to record those with my 50 mm Macro lens.

We left the rattler alone - with trepidations. Rattlesnake venom is mostly haemotoxic, extremely painful but rarely deadly to larger animals and humans. But with squirrels becoming more and more immune to it, Mojave Rattlers co-evolved by producing a neurotoxic venom component known as Mojave Type A toxin- which puts them in the same class as the deadly Cobras.
This snake had a very small rattle for her 2.5 foot body length. A rattler adds a section to its rattle each time it sheds its skin which happens several times per year. This one must have broken off parts of it. She also never bothered to rattle even though I was very close.



Cody was strolling around but never noticed her. He is snake trained (the hard way) and he flinches even from black and white ribbons, curved branches, or the smell of my snake stick. Occasionally he's fooled by a Gopher Snake. He has a clearly recognizable, rhythmic 'snake bark' that will alert me from my deepest dreams. Rolling out of bed, grabbing some shoes, the snake stick and a flash light, then locating and holding the snake until Randy arrives with a container, has become the routine of hot summer nights when the snakes seem to follow the walls of our house right to the patio and the dog beds. The following morning we carry the captive out to the adjacent State Land for photo shoot and release. From May to September last year we had to move 14 Diamondbacks from patio and dog-run. Elsewhere on our property we leave the snakes alone and appreciate them with the rest of 'our' wildlife.
Western Diamondbacked Rattler
Crotalus atrox