The Bicknell's Thrush

Bicknell's Thrush (Catharus bicknelli)

A guest to protect!

Due to its climate, Mont Sainte-Anne is a favorite spot for this bird. The limited number of specimens recorded in Quebec as well as the pressures exerted on its habitat, command sustained efforts for the preservation of this bird.

It's an invitation to discover and protect it!

Bicknell's Thrush was discovered in 1881 by Eugene Bicknell, New York State, but was designated as a distinct species only in 1995. Prior to this date, she was considered a subspecies of the Gray-cheeked Thrush that resembles her a lot. It was a Canadian ornithologist, Henri Ouellet, who finally persuaded the scientific authorities that Bicknell's Thrush and Gray-cheeked Thrush were two distinct species. As this thrush prefers habitats that are difficult to explore by humans and is rather rare, it remains one of the least known bird species in North America.

The Bicknell's Thrush is a migratory bird, passing through Quebec in summer for nesting. His presence here is a privilege for all birdwatchers and nature lovers.

The Bicknell's Thrush is a small bird the size of a sparrow. The male and the female are almost identical, the male being a little bigger. Measuring from 16 to 18 cm and weighing between 25 and 30 g, the Bicknell's Thrush is one of the smallest thrushes in the Catharus family. A pale yellow hue is drawn from the face of the bird to half of the lower mandible or a little further. When observed from a distance, the bird seems almost entirely dull olive brown. His thorax, a striking buff color, is dotted with small dark spots, which also decorate his chin, chest and flanks. Its legs are purplish brown, and its feet are pale yellow. His big eyes have evolved to allow him to see.

This bird :

  • is rare: there could be as few as 4 000 in Canada
  • is the only bird that nests exclusively in northeastern North America
  • has a nest guarded by up to four males
  • is one of the least known birds in North America

Reproduction

The Bicknell Thrushes have an unusual mating pattern. In fact, females mate with more than one male. Such mating practice has not been observed in other thrushes. Up to four males perform tasks related to the same nest, including feeding chicks.

It appears that the adult Bicknell's Thrush returns to the same nesting area each year. Bicknell's Thrush breeds when one year old. Males arrive at breeding grounds in the middle or end of May, usually a few days before females. Shortly after reaching the breeding grounds, the male opens the mating season by singing all day to signal its availability to the arriving females. If the cold persists, the song may become intermittent until the weather is softer.

Shortly after the start of mating, a nesting site is chosen, probably by the female. The birds begin to build the nest in early or mid-June. It is usually located in a dense stand of young spruce or fir trees. Birds usually put 7 at 10 days to build their nest, but if it is destroyed by a predator or by accident, it can be rebuilt in just two days.

The female lays one egg a day, usually in the early hours of the day. The eggs are usually bluish green. A clutch has three or four eggs. The female begins to hatch, that is, to warm the eggs, after laying the penultimate egg, and she is the only one to do so.

The chicks are born about 12 days later. They have no feathers and depend entirely on adults to feed and keep them warm. Still 12 days and the chicks are unable to hold longer in the nest and are ready to fly. They remain around the nest and adults continue to look after them. They will be independent before the autumn migration which takes place in September. Each nest produces on average only one or two chicks and in years when the main predator of the thrush, the red squirrel, is abundant, let alone young birds survive.

Habitat

The Bicknell's Thrush breeds in very dense woodlands, composed of stunted trees dominated by balsam fir and red spruce and under particularly wet, cold and windy conditions. This climate is important for its survival, as its reproductive cycle depends on it. It will reproduce and raise its young in these forests.

In Percé, the Bicknell's Thrush frequents Mont Sainte-Anne. His presence is a privilege for all. Although Mont Sainte-Anne has a lower peak than most places frequented by Bicknell's Thrush in Quebec, it is still a prime location. Indeed, since this bird enjoys a cool and wet climate during its breeding season, the proximity of the Gulf of St. Lawrence ensures sufficient amounts of rain, which are accompanied by a cold and wet breeze. Mont Sainte-Anne is therefore a favorite spot for this bird.

After a stay of only four months, Bicknell's Thrush will begin a migration of more than 2 000 kilometers to the south, to reach the Greater Antilles before the start of winter. Each journey north or south leads the Bicknell's Thrush to an uncertain future.

Vulnerable species

This bird is also so sensitive to disturbances that it abandons its nest at the slightest disturbance. Because of its vulnerability and limited knowledge of the size and distribution of its population, Bicknell's Thrush has recently been classified as Special Concern in Canada by the Committee on the Status of Endangered Wildlife in Canada and Canada. Quebec is one of the vulnerable areas.

Several changes in the environment are detrimental to this bird. The Bicknell's Thrush is sensitive to the slightest fluctuations in its environment which makes it very vulnerable to human activities that alter its habitat as well as rising temperatures, among others, caused by the phenomenon of climate change. Logging, the construction of telecommunications towers or wind turbines are all activities that reduce the forest area and therefore the amount of habitat available for Bicknell's Thrush.

Protection of the species

The Geopark project at Mont Sainte-Anne and all that this entails as changes, namely the installation of infrastructures, the creation of new trails, thus causing an increase in the number of visitors to the site, are factors likely to affect the reproductive cycle of Bicknell's Thrush. In fact, the fragmentation of the territory and the alteration of the habitat are the consequences feared by all these changes.

As a result, a lot of work needs to be planned, including an extensive awareness campaign to promote its value and importance in the Mont Sainte-Anne landscape. The interpretation panels on the species can help to identify it but also to explain the issues related to its survival. In this sense, an action plan is desirable, in which it is strongly recommended to carry out a biennial evaluation of its population. Finally, the legal protection of the Bicknell's Thrush can be entrusted to a recognized and specialized organization, which would be mandated to the good management of the grounds. For example, the Nature Conservancy is an organization of its kind whose mission is primarily to protect endangered species.

In addition, a coalition of scientists, natural resource managers and conservation planners forming the International Group for the Conservation of the Bicknell's Thrush (GICGB), is dedicated to the study and conservation of this songbird. mysterious and fascinating. The efforts of the GICGB have resulted in an innovative action plan to ensure that Bicknell's Thrush does not become an endangered species, to the delight of all.

References

Identification of the Bicknell's Thrush range in the Mont Sainte-Anne area, Nature Conservation Study, August 2011.

Greg Campbell "Bird Studies Canada - Atlantic Region, New Brunswick"

http://www.bicknellsthrush.org/