Black-tailed Rattlesnake (Crotalus molossus), Little Ray's Reptile Zoo, December 20, 2008.

Black-tailed Rattlesnake (Crotalus molossus), Little Ray’s Reptile Zoo, December 20, 2008.

Some links on venom, rattlesnakes, and rattlesnake venom:

  1. In April, BBC Earth explored venom overkill — why are jellyfish, snake and other creatures far more venomous than they need to be, especially given the metabolic cost of producing venom? The answer is deceptively simple: “[t]here’s no such thing as absolute toxicity” — venom is tailored to specific prey that may have evolved resistance to it.
  2. Most North American rattlesnake venom lacks neurotoxins, but a recent study finds that their common ancestor did have the genetic ability to produce neurotoxic venom 22 million years ago. That ability has since been lost to specialization (see above): Western and Eastern Diamondbacks lost the ability to produce neurotoxins about six million years ago; Mojave Rattlesnakes, whose venom is neurotoxic, lost a myotoxin gene about four million years ago. [Science News]
  3. A 36-year study of a population of Timber Rattlesnakes in the Adirondacks found that female rattlesnakes waited, on average, until they were 10 years old before having their first litter, and that most had only one litter in their whole lives. This has serious conservation implications. [via]