CORNER BROOK Bird populations may be a sign of the health of the environment, but declining numbers don’t always mean there is something wrong with the local habitat.
A recent report by BirdLife International, an organization based in the United Kingdom, indicated that 1,313 species — one in eight globally — are considered to be at threat of extinction and their continued decline is a warning of trouble in the environment in general.
Gros Morne National Park is marking its 40th anniversary this year. Ever since the park was established in 1973, there has been extensive monitoring of bird populations, resulting in records of the sort that would be hard to find anywhere else in Canada.
Those studies have shown increases in some populations thanks to the establishment of protected areas, improved waterfowl harvest management, habitat protection and banning harmful pesticides.
Some species, such as the grey-cheeked thrush, have not fared so well. Once the fifth-most common songbird found in Gros Morne National Park, has dropped 95 per cent since the early 1980s.
Last week, Parks Canada staff assisted a group of researchers from Utica College in New York studying the genetics of the Newfoundland subspecies. In all, seven birds were captured and banded in the Main River watershed, just east of the park.
Numbers of other species found in Gros Morne, such as the rusty blackbird, olive-sided flycatcher, Newfoundland red crossbill, bank swallow and red knot have fallen by 50 per cent in the last three decades.
“Most of these species are migratory and may be declining due to factors acting during migration or on the wintering grounds,” explained Darroch Whitaker, a species conservation specialist with Parks Canada in Gros Morne National Park.
“This highlights the fact that conservation is a global concern that requires a high level of good faith and cooperation between nations.”
The red knot, for instance, migrates from the tip of South America to the high Arctic. It has traditionally depended on feeding on horseshoe crab in Delaware Bay halfway through its journey.
In recent years, the horseshoe crab fishery has become lucrative and, with crab stocks heavily harvested, the red knots numbers have declined.
“One step along the way in a long migration can actually disconnect the whole system,” said Whitaker. “What we can do is provide them with the best possible habitat while they are here to help them get back to where they came from.”
One of the better known endangered species in Newfoundland and Labrador is the piping plover. There are between 25 and 30 nesting pairs of plovers, who require sandy beaches to successfully reproduce.
Fortunately some of these beaches are in communities or, in the case of Shallow Bay and Western Brook in Gros Morne, within a protected park area. Still, people enjoy those same sandy beaches the plovers need.
All it takes is one careless person on an ATV to run over a nest or one stray dog to snap up eggs and the plover’s hopes of reproducing are dashed for the season.
“The park offers ideal habitat for the species because, as a protected area, its beaches are free from many of the types of disturbance and habitat degradation that plovers face in other areas,” said Whitaker.
Parks Canada is currently in the process of developing an integrated Species at Risk Action plan for Gros Morne National Park, which Whitaker said will help to focus recovery efforts and promote opportunities for visitors to learn about imperilled species.
Moose-induced changes in the Grose Morne forest habitat are affecting bird populations. High consumption rates of the trees mean less healthy habitat for species such as magnolia warblers, black-throated green warblers, boreal chickadees and ruby-crowned kinglets. At the same time, those same changes in forest structure favour birds such as white-throated sparrows, fox sparrows, and mourning warblers that prefer more open habitat.
Gros Morne National Park is currently engaged in an initiative to promote forest health in the park, largely through reduction of the moose population, which should return balance to the composition of forest habitat in the park,” said Whitaker.
A number of other songbird species have been increasing in more populated areas, likely because of cleared land and the presence of bird feeders. Species such as saw-whet owls, common eider ducks and bald eagles have also enjoyed an upturn in their numbers in recent times, said Whitaker thanks to conservation measures that have been taken.