Recent studies have shown that animals previously considered to be utterly asocial actually exhibit strong social skills similar to humans, bordering on genuine altruism and sense of community.
Q: In your work, you’ve found that some snake species actually spend quite a bit of time together. One of your current studies1 explores the idea that some members of rattlesnake families maintain close ties. Can you tell us more about that?
A:In rattlesnakes well-studied enough to know, families stay together until the babies have shed their skin for the first time – ~7-14 days after birth[old enough to hunt for their own food]. And in the few species we’ve investigated, it doesn’t stop there. Timber rattlesnake (C. horridus) juveniles and adult females tend to associate more closely with their relatives at communal dens and rookeries (gestation/birthing sites)2. In our work with Arizona blacks, we’ve observed that many babies end up at their mother’s den (we’ve never observed one at a different den) and continue to associate the following spring.
Q: You’ve observed3,4 mother rattlesnakes protecting and caring for their young. What are some of the ways in which they do this?
A: Newborn rattlesnakes are much smaller and less wary of threats than adults, so the simplest form of care mothers do is to be present (or watching nearby) when babies are on the surface. When the babies are very young (~1-3 days), mothers tend to keep them very close and will herd them back if they move away. If the nest is threatened, the mother will employ the usual rattlesnake defenses: posturings, rattling, and probably striking/biting if it escalates that far (not something I’ve personally tested ). Greene and colleagues previously documented similar behavior in other rattlesnake species. Like other animals, their behavior develops: babies become less naive and mothers less protective during that 1-2 week period.
Q: You’ve also found6 that rattlesnakes will help “babysit” the offspring of other rattlesnakes. What do the snakes do when looking after these other young?
A: Except for threatening potential predators, we have observed babysitters doing everything we’ve observed in mothers. Whether they don’t defend, or we haven’t observed it yet, we don’t know (haven’t tested it). Unless the babysitter is a male or still-pregnant female, genetic testing is required to determine if it’s babysitting, so this behavior has likely been observed more often than we think.
T. animalcognition.org
On mutual attraction between parent and offspring
The researchers tested 16 rattlesnake families by putting the mother in one side of a terrarium and the offspring in the other. To see whether the youngsters were drawn to the mother, the researchers connected the compartments with a tube lined with rows of nails. The little snakes could fit between the rows of nails, but the mothers couldn't. By the third afternoon, 84 percent of the newborns were in the mother's compartment, May and his colleagues reported in 2002.
To see whether mothers were attracted to their young, May and his colleagues divided a terrarium in two with a cardboard partition low enough for an adult snake to cross but too high for the babies to manage. In the experiment, more than half the adult snakes climbed over to their young. Eight stayed there throughout the experiment, and four others made multiple trips. Of the 23 barrier crossings, 18 went toward the side of the babies.
Yes, there is a mutual attraction, the researchers concluded.
T. phschool.com