Venomous Snake 'Olympics' Held in Australia
Venomous snake competitions were recently held in Australia, according to a new study that describes the events: sprint trials in a racetrack, tongue flicking, thrashing, biting when held, and wrapping around other bodies.
(Broad-Headed Snake; Credit: berichard)
The goal wasn't to determine the best snake athletes, but rather to study the participants' defensive responses under various conditions. The findings are published in the latest issue of the journal Herpetologica.
Two species of Australian elapid
snakes— small-eyed snakes (Cryptophis nigrescens) and broad-headed
snakes (Hoplocephalus bungaroides)— were selected to participate in
the trials. Both are nocturnal but vary widely in their foraging
patterns, which might explain differences in their defensive responses.
The scientists found that if you ever encounter such a venomous snake in the wild in Australia, you'd better hope it's a small-eyed one. That's because they are more likely to flee than fight when they feel threatened. Small-eyed snakes travel widely to forage for food, while the
broad-headed snake will lie in ambush within sun-warmed rocky retreats.
I can't imagine that the snakes enjoyed this 'Olympics' much, since the events involved a fair amount of annoying, yet harmless, poking and unwanted handling.
For example, during the speed test trial, the University of Sydney's Richard Shine and colleagues poked snakes in the tail with a paintbrush to urge them to move forward. They then measured how fast the snakes slithered.
Another event involved a researcher grabbing the snakes with a gloved hand to observe their response to predators. All of the events were tested at three different temperatures—20, 68, and 86
degrees Fahrenheit—and during both darkness and bright illumination,
simulating night and day.
Here's what the scientists determined:
• Because they are nocturnal creatures, the snakes displayed more
intense antipredator behavior at night than during daylight hours.
When cold, both species of snakes tried immobility as a defense,
becoming more vigorous in their responses at warmer temperatures.
Small-eyed snakes experienced less decline of their sprint speed and
alertness at lower temperatures than did broad-headed snakes. This would
be expected of an active nocturnal forager like the small-eyed snake
and gives it a better chance to flee.
• The wait-and-pounce habits of
the broad-headed snake would leave it less prepared to flee, but also
in a better location to make a stand, such as in a crevice or near rocks
rather than out in the open.
Both species of snakes most often
chose to flee from the perceived predator, but the broad-headed snake
more consistently switched to retaliatory behavior and responded more
intently at higher temperatures.
The full study can be downloaded online.