WatchList Species Account for Manx Shearwater |
Qualifies for the list as a Declining Yellow List Species
|Photo: Glen Tepke
The best-known and most northerly-breeding of the shearwaters, the Manx Shearwater breeds primarily in Iceland, the Faeroe Islands, Great Britain and Ireland, France, and possibly the Azores, Madeira and the Canary Islands; it now also breeds locally in Atlantic Canada and perhaps the U.S. It nests on remote, uninhabited islands with few mammalian predators, from sea level to over 3,200 feet.
Habitat is open grassy areas with few trees and shrubs but with soils suitable for excavation. This species nests in burrows, dark recesses under rocks, and even in crevices in human-made structures. Both sexes excavate or repair the burrow, which may be up to nine feet long. Like other tubenoses, the Manx Shearwater makes feeding visits to the nest at night.
During nonbreeding season, this species is found mostly in the southwest Atlantic off the coast of South America. It feeds on small,schooling bait fish, including herring, sardines, and anchovies, and often associates with marine mammals, including dolphins and pilot whales.
Total numbers are estimated at 4-500,000 pairs. Populations are now stable or slowly increasing, but large declines have occurred during the last several hundred years at some colonies, for example on the Faeroe Islands and the Isle of Man, where nearly the entire population was extirpated by rats in the 19th century.
Conservation measures include the provision of artificial burrows, readily accepted by these birds; gull control is another method that has proven effective in Britain.