Overkill?

[Luvyna]

As far as rattlesnakes, I'd say it's "instinct" to bite first no matter what. They're very quick to bite because they cannot constrict...venom is their only weapon. If you were to offer prey that was already envenomated (say, by another rattlesnake*), they'd be able to smell the break-down of tissues caused by the venom & may overlook the need to bite first & just eat it. *I know because when I kept rattlesnakes, I had one that was venomoid (venom glands removed for previous owner) & he had very poor digestion as a result, to the point that his stools were oily & smelly, and he couldn't gain weight (his body was triangular); for some reason, he had a weak stomach. In a rattlesnake, venom is similar to our saliva & begins the digestive process, then stomach enzymes complete the process, but in that individual rattlesnake, it wasn't apparent that his stomach wasn't up to the task until after they had surgically removed his venom glands. There is no "putting them back" either, so when he was turned over to me, I first tried adding digestive enzymes to his f/t prey, with no success. After that I decided to try a "venom-donor"...I had a wickedly venomous Western rattlesnake that was all too happy to bite as many extra rodents as I presented him with, though he did seem to give me dirty looks when I stole them with my 24" tongs. It was only then that the other rattlesnake (a large Eastern Diamondback) was able to digest prey & gain weight properly.

It's true that venom is a valuable resource that requires a good high-protein diet to "manufacture", but only a tiny bit needs to be installed to kill their typical rodent prey. One "fully-loaded" rattlesnake can envenomate quite a few rodents, one after another, without ever running out. I never tested my 'room-mates' to see just how many, I only know that several extras (enough to fill up a large hungry adult Eastern Diamondback) & then a few more for himself never presented any issue for my "venom donor" rattlesnake.

As far as the larger constrictors that appear to take a long time constricting their prey, it might be that because of their overall size, they feel less threatened by other predators, whereas many of the snakes that I routinely see wolfing down their prey tend to be the slender colubrid types, & they're much easier for other animals to pick off while they're eating...so maybe that explains it??? I'm just guessing...but it makes sense. Different species have evolved with their own habits for a reason...because they worked and the snakes survived.

Wow, thanks for sharing this story Bogertophis! That poor snake who had his venom glands removed It's so cruel that anyone would do that especially since venom is essential for the snake's digestion.

It's fascinating that the donated venom made such a big difference in the Eastern rattlesnake's digestion (even though it was a Western's venom), great job finding a creative fix to the problem with that very eager donor snake! It's pretty funny imagining the disgruntled Western watching you take back the prey that he "killed." Glad you were able to get the skinny Eastern back on track with this method.

Love this thread. Would be interesting if anyone could find research supporting constricting live prey only until the heart stops beating vs. dead prey. I noticed mine hold on to the f/t much longer, too!

Apparently scientists only recently discovered that constrictor snakes kill by stopping the heart and disrupting the cardiovascular systems of prey instead of asphyxiation. Researchers installed artificial heartbeats inside dead rodents and offered them to boas, finding that the boas would constrict prey without a heartbeat with less pressure and for a shorter time (around 10 minutes) while prey with a continuous heartbeat would be constricted for around 20 minutes with more pressure before the boa gave up. If the heartbeat stopped partway through the constriction, the boas would release the prey soon after.

Summary of the research (easier to read)
Original research article

It's pretty amazing that details like this are only being discovered now. There is so much we still don't know about snakes!