Evening Grosbeak
(Coccothraustes vespertinus)
Status: Special Concern (ESA 2018, SARA 2019)
Species Identification:
The Evening Grosbeak is a robin-sized finch, notable for its bold colours and large bill. The male has a black head with a thick yellow streak across his face. The body is golden-yellow, and wings are black with white patches. The female is a more subtle yellow with black and white streaked wings. Their thick bill is very powerful and can easily crush cherry pits.
Diet:
During outbreaks, more than 80% of their diet consists of Spruce Budworm pupae and larvae. Spruce Budworm will harm trees by eating buds and leaves, so Evening Grosbeaks are an important predator. They also feed on other insects like caterpillars and aphids. Outbreaks of Spruce Budworm in Ontario are related to summer and winter minimum temperatures, which are being affected by climate change. The outbreaks are also related to the forest composition, especially the presence of Balsam Fir and White Spruce. Between outbreaks, Evening Grosbeaks rely on seeds and berry pits from shrubs and trees. In the winter, they are attracted to berry-producing ornamental plants and feeders, especially those with sunflower seeds. They will also drink maple sap by snapping off small twigs.
Habitat and Range:
The majority of the Evening Grosbeak’s habitat is within the Boreal forest in Canada. Their range extends across the country from the Pacific to the Atlantic, and into the southern edge of the Yukon and Northwest Territories. The range extends south of the border into some northwest states like Washington and Oregon, and in the east from Minnesota across to Maine. There are isolated populations in the interior of Mexico, and some scattered across the southern United States. Historically this species was only found on the western half of the continent, but it has moved eastward over the past century, following the spread of spruce budworm outbreaks.
Within Canada, Evening Grosbeak populations are highest in BC, Ontario, and Quebec. Ontario is home to 12.8% of the global population of Evening Grosbeaks, or about 500,000 individuals. It breeds across Ontario with higher concentrations in the Lake of the Woods region, east of Georgian Bay, and along the southern edge of the Canadian Shield (including The Land Between).
The Evening Grosbeak lives in mixed-wood or coniferous forests. Dominant trees are typically firs, spruces, larch, pine, and aspen. Nesting habitat includes large, mature trees with open canopies. Only some flocks of Evening Grosbeaks will migrate to the United States for the winter, most others will remain behind.
Biology and Behaviour:
Evening Grosbeaks are irregular breeders in Ontario since they follow Spruce Budworm outbreaks and base their breeding off of their success. Any adults that migrate to the United States for the winter arrive at their Ontario breeding grounds in late April or early May. Females build a nest high on a conifer branch out of twigs and roots. They lay 3-4 eggs which are incubated for about two weeks. Nestlings are fed for another two weeks before they leave the nest. Researchers have recorded the oldest Evening Grosbeak to be 15 years old, but the average age is around 3-4 years. Known predators include raptors and domestic cats, and nests may be preyed on by corvids.
Similar Species:
- The American Goldfinch is much smaller with a smaller bill, and male has a black cap
- The female Evening Grosbeak looks similar to the Pine Grosbeak, but the Pine Grosbeak has a black beak and is more grey-tinged than yellow
Conservation and recovery strategies:
An estimated 9% of their Canadian habitat is on protected land, with most of their range on public land. More research on their northern range should be conducted. Surveys tend to be biased towards southern parts of their range which are more heavily populated. Since this species is listed as Special Concern in Ontario, there are no direct conservation efforts for population and habitat at this time.
Quick Facts:
- The unexpected presence of an Evening Grosbeak may be an early indicator of Spruce Budworm infestation
- Populations of Evening Grosbeaks increased after decades of fire suppression resulted in more available boreal forest habitat. Numbers have been declining in relation to increased logging of these forests
- Evening Grosbeaks show a strong preference for Manitoba Maple seeds, which are often planted ornamentally
Additional Resources:
- Cornell Lab of Ornithology page
- FLAP Canada’s website at https://flap.org/
- See the Hinterlands Who’s Who page for fun facts and pictures
- COSEWIC Assessment and Status report, 2016
Sources:
COSEWIC. 2016. COSEWIC assessment and status report on the Evening Grosbeak Coccothraustes vespertinus in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xi + 64 pp.
Hoar, T. 2007. Evening Grosbeak. Pages 626-627 in Atlas of the Breeding Birds of Ontario, 2001-2005. Edited by M.D. Cadman, D.A. Sutherland, G.G. Beck, D. Lepage, and A.R. Couturier. Published by Bird Studies Canada, Environment Canada, Ontario Field Ornithologists, Ontario Ministry of Natural Resources and Ontario Nature. 706 pp
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