In 1983, one year after publishing The Amphibians and Reptiles of
Manitoba, Bill Preston, then curator of herpetology and ichthyology
at the Museum of Man and Nature, heard a Great Plains toad for the first
time in Manitoba. "It has a pulsating, metallic trill that's quite
different from any of the other frog calls,"
According to Manitoba Conservation Data Centre zoologist Jim Duncan,
less than a dozen known occurrences have been mapped for the toad in
Manitoba - until 1999. Heavy rainfalls in spring and early summer in
southern Manitoba that year have resulted in 40 additional sightings of these
blotchy, olive-colored toads that have prickly looking skin. "We've
had more sightings of breeding toads identified this year than any
other," Duncan said. The Great Plains toad is an irruptive breeder,
meaning it does not breed on an annual cycle.
"These toads breed only after heavy and violent rain,"
Preston said. "They carry on calling some time after, up to three
or four weeks." Ken DeSmet, endangered species biologist with
Manitoba Natural Resources, first heard the toads calling the evening of
May 15 while at his home near Melita in southwestern Manitoba.
"I was surprised when I heard them," DeSmet said. He had
spoken with Preston and didn't anticipate hearing the toads until the
weather had warmed up. "I could heard these calls so I raced out in
the truck and there were a whole pile of them."
The toads are adapted to the broad expanses of prairie habitats and
according to Preston, their calls can be heard up to four kilometres
away. Preston said the toads have probably always been in the area, but
just haven't announced their presence with calls. They can spend weeks
at a time underground during dry conditions. Despite recent sightings,
the Great Plains toad will remain a species of concern in the province.
"While it appears the toad is more abundant than previously
thought, it still warrants close attention due to its limited range in
Manitoba," Duncan said. The Great Plains toad was recently listed
nationally as Vulnerable by the Committee on the Status of Endangered
Wildlife in Canada.
Other Manitoba species assessed and listed for the first time this
year include the Yellow Rail (designated as vulnerable), a small
ground-dwelling marsh bird that is threatened primarily by wetland
drainage, and Sprague's pipit (designated threatened), a grassland bird
that breeds in southern Manitoba and is threatened by overgrazing and
occasional brown-headed cowbird nest parasitism.
- reproduced with permission from the Manitoba Conservation Data