Writing in the current issue of the journal Animal Behavior, researchers from the University of Grenada report that female Mexican lance-headed rattlesnakes frequently consume infertile eggs and non-living young after giving birth. This is said to be the first documented case of cannibalism among rattlesnakes (please see below for my observations, however). Interestingly, with a sole exception, the females did not consume young that were born alive, even though these remain inactive for several hours after birth, and appear (to us, at least!) to be dead.
Rattlesnakes bear live young, and females use up a great deal of energy and body mass during gestation (they do not feed while gravid). It is theorized that consuming those young which are dead upon birth helps them to recover their strength.
Rattlesnake Cannibalism in another Species
While working with the comprehensive rattlesnake collection at NYC’s Staten Island Zoo, I had the opportunity to participate in breeding efforts for a number of species. Most births occurred at night and were not filmed, so I cannot say if females of other species ever consumed non-living young. However, newly born Neo-tropical rattlesnakes (Crotalus durissus) did consume litter-mates on two occasions.
Hog Fat and other Unusual Snake Foods
Contrary to popular belief, many snakes consume non-living prey (i.e. carrion) in the wild. The most unusual incident I recall was a note published in the journal Herpetologica…a water moccasin (Agkistrodon piscivorous) was observed stripping fat from a road-killed feral hog!
Of the snakes I have worked with in the field and captivity, moccasins, indigo snakes, black racers and anacondas stand out as taking the widest variety of prey species, and each engages in cannibalism. One particularly large moccasin I cared for consumed a northern water snake that shared its exhibit (not my idea – I had moved on by then!!). I’m sure the same occurs in the wild, in areas where moccasins and various water snakes co-exist.
A Collection for Rattlesnake Aficionados
I had the wonderful opportunity of participating in the renovation of the Staten Island Zoo’s reptile house, former stomping ground of legendary snakeman Carl Kauffeld (known to all snake keepers as the author of Snakes, the Keeper and the Kept and Snakes and Snake Hunting).
As in former times, the zoo now boasts an impressive rattlesnake collection…please visit if you have the opportunity. Pictured here are a few exhibits that I set up for the opening – Neo-tropical rattlesnakes, banded rock rattlesnakes and desert Massasaugas.
Lance-headed rattlesnake photos and natural history information are posted at: