Weatherhead said the environmental domino effect could mean a reduction in some native bird populations because the snakes he studies are important predators of birds' nests. During the night, in addition to eggs and young birds in nests, adult females may also get caught unawares.
"Females are often on the nest incubating eggs or brooding the young at night," Weatherhead said. "If they are doing that during the day and a snake approaches, they rarely get caught by the snake, but at night they are much more vulnerable because snakes are very stealthy and the incubating birds don't detect the snake approaching. This is good for the snake because it gets a bigger meal.
"The environmental repercussions could be significant if you start eliminating adult females from a population, particularly an endangered species," he said. "The loss of females for native birds will have a big demographic effect on bird populations."
Weatherhead is currently conducting another study in South Carolina comparing a species of snake that appears to only forage during the day with one that can switch to nocturnal foraging to understand more about the relationship between prey, predators and climate.
"We're looking at the whole community of nesting birds that the snakes prey on," he said. "We have cameras aimed at hundreds of nests to determine who the predators are, when the predation happens, and what the fate of the nest is both for the nest contents and the parent birds."
Weatherhead explained that snakes can find nests in the dark because they don't rely on vision alone to find birds' nests.
"Snakes have a really good sense of smell," he said. "We've done lab experiments in which we give snakes three choices under darker conditions. They can choos
|Contact: Debra Levey Larson|
University of Illinois College of Agricultural, Consumer and Environmental Sciences