Wednesday, February 23, 2011

Pine grosbeak

Nature Watch

By Susan Thurn,
Cable Natural History Museum

This past week my parents have had a special visitor at their bird feeders. It began for them as a flash of slightly different colors – a rusty head and rump, gray underneath, with two white wing bars. Out came their bird field guide to identify their guests as pine grosbeaks, and in this case my parents have been hosting first-year males.

Pine grosbeaks spend most of their time in the boreal forests of Canada, but their wintering areas are determined by food availability. When food decreases, they move to find the food, creating what we call winter irruptions. These irruptions are not common and are irregular for pine grosbeaks.

Pine grosbeaks flock together in winter, and they often frequent a fruit or berry tree until all of it is consumed. They eat through the fruits by biting it with their sharp pointed beak, discarding the pulp, and crushing the seed. Most of their diet is made up of plants, including buds, seeds, and seeds or fruit of spruce, pine, maple, apple, mountain ash, juniper and grass and weed seeds. They are also awkward flycatchers, catching insects, or even spiders. A breeding pine grosbeak develops pouches in the floor of its mouth for carrying insect and plant food to its young. They also eat snow or drink water every day.

Not as much information is available about pine grosbeaks. Even their populations are not well-known because it is difficult to gather data on this species. The boreal forests of Canada are believed to host most of the entire breeding population of pine grosbeaks and some other boreal bird species. Pine grosbeak irruptions are usually in intervals of five to twenty-five years. How lucky any of us are to have this bird species visit our back yards!

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, “In a New Light” photographic exhibit focused on the St. Croix National Scenic Riverway. Find it in Cable at 13470 County Highway M. Also discover us on the web at, on Facebook, or at our blogspot, to learn more about our exhibits and programs.

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