URI researcher gets the scoop on (rabbit) poop
New DNA technique may save New England cottontail
KINGSTON, R.I. -- March 29, 2000 -- Collecting rabbit droppings is a
messy job, but it might just be the key to protecting the rare New England
cottontail from extinction.
According to University of Rhode Island mammalogist Tom Husband of West
Kingston, populations of the once-common rabbit are declining rapidly.
"We're finding them less and less often. They look to be on the way
But Husband has perfected a technique for extracting DNA from the rabbit's
droppings that might just save them.
New England cottontails are almost impossible to distinguish from their
common cousin, the Eastern cottontail, which was introduced to New England
by hunters beginning in the 1930s. In fact, the only way of absolutely
determining which species is which is to examine a clean, undamaged skull.
"Since you can't tell them apart in the field, and they are very
difficult to trap, we don't have a very good idea of what their range is,"
explained Husband, a professor of natural resource science at URI. "But
if we extract DNA from rabbit feces collected from throughout the region,
we can provide an excellent picture of where the New England cottontail
is found and where the Eastern cottontail is found."
Identifying a species' range is a crucial step in managing its population.
"To manage the two rabbit species properly, you have to know where
they are and where they aren't and what kind of habitat they require,"
said Husband. "Range becomes very important."
Under Husband's guidance, URI graduate student Melanie Smith of Portsmouth
has been studying DNA extraction and purification techniques in the lab,
and conducting a survey of road-killed rabbits in Rhode Island in an effort
to determine their population. So far she has found very few New England
"We don't know why New Englands are declining so rapidly,"
said Husband. "It could be because of aggressive behavior by Easterns.
It could be habitat changes. It could be fertility levels. We just don't
Husband's research is especially good news for local rabbit hunters.
"The great fear in the hunting community is that if the New England
cottontail is listed as endangered, which seems likely, it may preclude
hunting of all rabbits," said Husband. That's because hunters can't
tell whether they are shooting the endangered rabbit or the common one.
"This research is in the best interest of the hunting community."
In 1996, Husband spent several months learning modern DNA techniques,
and he applied his new-found skills to identifying a genetic marker to more
easily distinguish between New England and Eastern cottontails. But since
rabbits are notoriously difficult to capture for every 100 traps set
out, most biologists only catch one or two rabbits he began experimenting
with new DNA techniques.
"Rabbits routinely drop fecal material all around their territory,"
he said, "and included in the feces are cells which have been sloughed
off from their intestines. Those cells are what we're testing."
The technique is being used by just a small group of researchers in the
world, mostly on animals that are very difficult to catch or see.
Soon Husband will also begin using the DNA technique in cooperation with
Lisa Dabek of Roger Williams Park Zoo in Providence, the world's leading
expert on the tree kangaroos of New Guinea.
"Biologists may study tree kangaroos for five years and only see
half a dozen animals," Husband said. "Extracting DNA from their
feces will help to distinguish between tree kangaroo species and establish
And just like with the New England cottontail, the effort comes not a
moment too soon.
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For further information: Todd McLeish 874-7892