Trying out a new policy towards rattlers

This one visited at breakfast on the patio today. The dogs raced at him, the Laika She-Wolf  just looked and quietly moved away. Frodo (coydog, bitten numerous times) stood close, but save, pointing. Bilbo ran around but stayed away. Cody, who should know better, barked and tried to get too close, so he ended up in time-out indoors. I hope he is not getting senile.

Packrat that was bitten by a rattler. The snake withdrew at first, then came back 5 min later and pulled it under the wood stack

We used to move all rattlers about a quarter of a mile away, only leaving a couple territorial old guys in their burrows. But they seem to be gone. Lately, we are so over-run with packrats that we are now opting to leave the rattlers be. This one is also a good active 'warner', even a hummingbird could set him off. So now he's curled up 10 feet from our table were the dogs are sleeping again and everything is peaceful so far. I looked him deeply between the eyes: he's a Diamondback.

On facebook, an interesting discussion about dog vaccination and treatment with antivenom developed. Of course I do not have any great answers, but at least some experience.
Here is one of the exchanges:

Terry D:
Your dogs all get the vaccine? First year I did for both mine.

Amy D:

I thought if your dog gets bitten it could die? That's why I started getting the anti venom shots. What is the truth about bites and dogs as a rule ? I know as a nurse at the hospital people get admitted right to Icu nowadays then down to the cardiac floor depending on age.

My opinion:
Generally, humans seem to be more sensitive than canines and cats. Wolfs and especially Coyotes probably had a long time to evolve with exposure to rattlers. Immunities do develop (evolutionary), as shown in prey species (Texas A&M). The validity of 'vaccine' has not been proven too well. 
My 5 dogs got bitten about 8 times in our 12 years here. The females and one male never, the oldest male once, the youngest, the coyote mix, 7 times. 

3 of our older dogs were also snake trained with electro-shock collars  and live snake exposure, but one of them was bitten right afterwards. 
The coydog was fed snakes by his mother in the den where he was born, I found the rattles.

We used antivenom once, iv overnight infusion of fluids twice, antibiotics several times (those snake teeth are full of germs). Anti venom after the bite may counter-act organ damage caused by the heamolytics of the snake venom. 
The coydog was treated after some bites, but not after others. He always had strong facial swelling, so none of the bites were dry-bites, but he always recovered after about 6 hours. Several times, he didn't even reduce his activity level and ept playing and eating, but was always very tender in the bite area. The last bite got him in the sponge of his nose and he wined. After that, he finally left the snakes alone, and he is a good, reliable 'snake-barker' now. But Amy mentioned age. And she is  right, that is a worrisome factor. My oldest male dog reliably stayed away after training, one bite and treatment (10 years ago) but he now seems to become forgetful and more grumpy...senile? All I can do is to keep him indoors during main snake activity, because I am afraid that a bite might be much worse for him now. 

It needs to be said that not all rattler venom is the same. Most individuals produce a 'cocktail' of venoms. There are heamolythic and neurotoxic components and the mix is evolutionary linked to the immunity that may have developed in prey species. So far, neurotoxins seem to be more prevalent in Mojave Rattlers than in Diamondbacks. The available antivenom blocks only haemolythic components. The neurotoxins, if present, would kill too quickly for any intervention anyway. Hence my attempt to correctly identify the snakes that are left in the immediate vicinity of the dogs.

There is the idea that younger snakes are more deadly than older ones because they have not yet learned to get the dose just right, so they inject always all their venom. I'm not so sure. I have seen big old rattlers bite a mouse which then just fell over and was dead. I watched a younger, smaller snake strike at a young packrat and the rat screamed (for minutes it seemed) before it finally died. The snake actually went into hiding and came back later to retrieve its prey.
 So the older snake must have administered a more potent bite. Of course, defensive bites may be different.     

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.

Yard Snakes in June

Our rattlesnake count for 2013 is finally going up. After several months without any visitors we first had the little one that the quail family pointed out. Then two nights ago, Randy, barefoot in sandals, stepped on a Diamondback that was concealed among some garden hoses on the brick terrace in front of the house. My husband is now turning on his flash light, not just carrying it. The rattler hid in a thicket of barrio petunias and could not be convinced to come out.

This morning a big rattler struck at Frodo on the steps of the back patio. It happened so fast, I heard a hiss but at first no rattle. Frodo has finally learned to fear rattlers (after 7 or 8 bites) and he backed off unharmed, only to let Cody take over the snake-barking duty. That rattler (photo) we carried out to the old lime stone quarry. When we crossed our fence to the state land the horses heard the rattle from the transport bin which has great accoustics. They threw up their heads and spooked with Cody in deliriously happy persuit.

When released from the bin, the snake recoiled and rattled. Trying to encourage him to move on, I threw some dry horse manure and sticks, not hitting him but very close. He didn't react at all to the flying objects, just kept his head turned toward me ready to strike. Maybe the  heat-sensing "pits" on his face read my thermal radiation and told him where the living threat was, or he could smell me. Looking at the photo I think his eyes look filmed over, so he may have been temporarily blind because he's close to shedding his skin. I'm wondering: what information do the heat sensors provide when the environmental temperature raises above the core temperature of an endotherm bird or mammal? Of course the rattlers are mainly night active in summer.

On the way home I was speculating how to test my theory (the one about the ignored inanimate clods of horse manure) on a non-viper, when Randy said "Like this one? Camera??"
A four to five foot Gophersnake was beginning his day with a dip in our bird bath. He was lying quietly, and as I watched him breathing while all of his body remained submersed, I found another physiological problem to ponder: He seemed to pump the air rythmically from his gular and neck region into his elongated lung (click to see video).  The entire rest of the body was lying completely motionless. I had never noticed this 'air gulping' in snakes before, just in amphibians. When the snakes left the water, its breathing movement became invisible.
Answer:  the lungs of a snake are usually ventilated almost exclusively by its axial musculature. That is the same musculature that is used for locomotion. What I saw in my 'water snake' was buccal pumping which is indeed a form of swallowing air  (into the lungs, not the digestive tract). It is used in situations where axial breathing is not feasable.

Gophersnake swallowing a rabbit. This is after the strangle hold is released

Another question: how do these constrictors breathe while they are squeezing the life out of a squirrel or bunny? How do they manage not to suffocate themselves? Buccal pumping doesn't seem possible then either, because the mouth is open. Maybe snakes, being heterotherm, just need so much less oxigen than their warmblooded prey that they can afford not to breath during this act. But what if the prey is a lizard?