Rattlesnakes are a much-dreaded phenomenon of the American Southwest. It’s important not to vilify them too much because
- They help to keep mice and other rodent pests to manageable numbers
- They don’t attack unless cornered – they’d much rather slither away
- Their skins are highly sensitive and they can feel pain
- Only literally a handful of people die in the US from the thousands who are bitten by venomous snakes each year
- Several species of rattlesnake are endangered in many US States
All that having been said, most snakebites in North America are from rattlesnakes and of the various types of rattlesnake, the Western diamondback comes out top.
Rattlesnakes have their enemies, particularly when newly born. The female appears to have live young, but she in fact carries eggs which hatch inside her. She will, to an extent, look after her brood, but this doesn’t stop birds, animals and other snakes from killing her babies and she normally reproduces only once every 3 years. A great many rattlesnakes are killed in round-ups and deliberate extermination campaigns as well as being run over by cars when they’re lying basking in the middle of roads.
The rattle of a rattlesnake, which is used to warn off predators it would rather not engage with, is made of hollow interlocking segments of keratin, the material from which hair and fingernails are made. Every time a snake sheds its skin, it grows another segment. However, unlike tree rings, the number of tail segments isn’t a reliable guide to the age of a snake because very often the end segments fall off. It might have been a handy guide, though, because it’s the older snakes which have the more potent venom.
One thing to bear in mind is that some rattlesnakes don’t rattle, and this is becoming more the case particularly in urban areas. The reason is that naturally occurring snakes which either can’t or don’t rattle are being favoured in the evolutionary process, since they more often avoid being killed by humans.
Some snakes don’t rattle and some snake bites don’t inject venom. If the skin around the fang marks hasn’t swollen up after 8 hours, then you’re in luck – there was no envenomation. Around 20% of bites are ‘dry’ like that. The other side of the coin is that a rattlesnake can control the amount of venom it puts in you. If you brush against it by accident and it’s feeling good about life after a hearty meal, then it’s likely to pump less venom into you. However if you step on it and it’s hungry as well as angry, you’re likely to cop the whole contents of its venom sack.
The main factor in whether a snakebite victim lives or dies is how quickly they’re got to hospital where antivenom is usually given. Knowing what kind of snake it was – by careful field observation – can be vital. Other than that, the advice is mainly to stay calm because a lower heart rate slows the spread of the venom. No tourniquets, no incisions, and no sucking out the bite. Concentrate on getting to a medical facility with all speed.