Relocating 'nuisance' animals often unhealthy for wildlifeFebruary 14th, 2014 in Biology / Ecology
URI graduate student Anne Devan-Song holds a bamboo pit viper as research assistant Vignesh Mohandasan looks on. Credit: Anne Devan-Song
(Phys.org) —It's a common phenomenon around the world: when humans observe wildlife in their neighborhood that they consider a nuisance, they call government wildlife officials to have the animal removed and transported elsewhere, often great distances away. It makes people happy to think they are ridding themselves of a potential problem without killing the animal.
What they don't know is that they may be killing the animal after all, and it can be a long, slow death.
That is the finding of a study by University of Rhode Island graduate student Anne Devan-Song, who studied the conflicts between people and snakes in Hong Kong, a region of high population density and high snake density and diversity.
"Human-animal conflicts happen everywhere, but translocation of the animals should be the last option considered," said Devan-Song, who collaborated on the research with URI Assistant Professor Nancy Karraker. "It should only be used if it has been proven to work."
Relocation of wildlife appears to be successful with some species, including some larger mammals and tortoises, but Devan-Song says that it doesn't work for snakes and it does not appear to be very successful with many other small animals.
The URI student studied the relocation of bamboo pit vipers , a small, slow-moving venomous snake commonly found in rural and suburban regions of Southeast Asia. They eat rodents, lizards and frogs and are highly adaptable to a wide variety of habitats.
In her research experiment, she placed transmitters on resident snakes and on snakes that had been relocated to a national park far from where they were captured. Most of the relocated snakes died within a year.
"Snakes know their home range really well, so if they're dropped off someplace else, they take off and make all sorts of unusual movements that aren't typical of snakes," Devan-Song said. "The more they move, the less time they spend eating, reproducing and finding hiding places. Movement is a good indication of how well the animals were doing, and the relocated snakes moved a lot and didn't do well."
Most of the relocated snakes were killed by other animals or run over by vehicles, and Devan-Song said that some appeared as if they had just given up and died a slow death from stress.
"Long-distance translocation is clearly not the answer to the snake-human conflict. We shouldn't be wasting time and money on it," she said.
She recommends instead a short-distance relocation to the nearest natural habitat, which may be as close as 20 yards away and probably no farther than 500 yards away. That way the animal does not become completely separated from its home range.
"In the case of bamboo pit vipers, I'm quite sure that they'd never be seen again, since they prefer to avoid people. But I suspect people aren't going to like the idea of short distance translocation," said Devan-Song. "With public education, I'm hopeful that short distance translocation will work, especially in snake-tolerant communities. Otherwise, euthanizing the animals might be a better answer, since it's more humane than a long death."
Devan-Song's next step is to share her results with the public and wildlife officials.
"There is a widespread notion that translocation works. People want to save the animal, take it away from the area and put it in a pristine environment," she concluded. "But it's not that simple. They don't understand that individual animals are tied to their home range. There are many things to take into account when considering translocation."
Provided by University of Rhode Island
"Relocating 'nuisance' animals often unhealthy for wildlife." February 14th, 2014. http://phys.org/news/2014-02-relocating-nuisance-animals-unhealthy-wildlife.html