|Flocking Robins - Kirk M. Rogers|
|Robin flock on the ground - Denaple|
|European robin - Wikipedia|
Watch a robin in your yard for a minute and you will probably see it grab an insect or extract a worm. In the winter when insects are scarce, the Canadian robins migrate south to the Midwest, driven primarily by the need for food resources. Now they show their frugivore tendencies, eating all available berries. They look for soft mast and find plenty hanging on into the winter. Some berries like our deciduous holly are bitter in the fall but "ripen" during the winter, providing food at a time when other resources are gone.
An overgrown cedar glade behind our house provides cover and lots of cedar "berries," actually miniature cones but all the same to a hungry robin. I suspect this is a major factor in the large flocks that we see. But we don't have any bragging rights with only 200 birds.
"The largest flock during the GBBC was reported from Mark Youngdahl Urban Conservation Area in St. Joseph, Missouri. Observers there estimated there were 5 million Red-winged Blackbirds along with a flock of 1.5 million American Robins." Great Backyard Bird Count
|Inebriated robin- karenbrockney.com/|
Geoff LeBaron of the National Audubon Society has been in charge of Christmas bird counts since 1987. He maintains one of the largest databases in ornithology.
"Historically most of the robins wintered pretty much in the deep south/southeastern U.S. Over the last 40 to 50 years they've increased significantly, especially in the northern and eastern part of their range. You're likely to see three or four times more robins when you're out on a Christmas bird count now than you were in 1965."There is a lot more on robin migration and winter habits at this Learner.org link.