Canada Goose Study Resumes

by Carl Strang

Last year I began a study of Canada goose winter roosting behavior in the western suburbs of Chicago, focusing on DuPage County. I found a number of roosting sites scattered around the county, open water places where the geese spent the nights. In the mornings the geese in the roosts dispersed, departing in groups of 20 or so, flying out to find food. In this suburban area, grazing on lawns was the primary winter fare. A period of severely cold temperatures froze three of the four largest roosts in January, and the birds departed the area rather than crowding into the remaining roost. By the time the roost areas thawed and the Canada geese returned, the time for territory establishment and migration had arrived for local birds and northern migrants, respectively, and the roosts quickly broke up.

Canada goose pair 3b

In September I noticed familiar winter patterns, with groups of geese flying out from the Blackwell and Hidden Lake roosts as I passed them on the way to work in the mornings. On October 12 I went to the Blackwell roost to make an assessment.

CG Blackwell 12OC 1b

Some geese, like these, already had left the roost by 7:30 a.m. and landed on nearby Silver Lake for preliminary staging. Others went straight to the lawns of Blackwell Forest Preserve and other nearby open areas to feed.

CG Blackwell 12OC 2b

A few hundred such geese had left the roost by then, and 1000 or so remained when I reached it. I found none of the tiny cackling geese, but I did see one distant individual wearing the orange neck collar that identified it as a Hudson Bay region bird. Thus some Canada geese had arrived from the north, but the roost had not reached its 2008-9 peak of 3000 birds. It seems likely that, in addition to a continuing influx of geese from the north, smaller local roosts such as the ones I observed last year are active. If last year’s pattern repeats, those satellites will merge with the larger roosts later as the smaller lakes freeze over.

Driving back home on the 12th, I saw a group of geese landing with others already feeding on the lawn at the edge of Butterfield Road near the Warrenville town center. Among the arrivals was an individual that stood out with much paler wings and back. It proved to have white (or nearly so) body plumage, but head and neck were normal colored.

CG leucistic 1b

I drove to where I could park, and took some photos in the dim light.

CG leucistic 2b

I suspect that this leucistic individual is a bird mentioned last spring by a friend, Anne S., who has observed it for several years. If it is the same goose, it usually feeds in another nearby location I don’t typically frequent.

CG leucistic 3b

I am hopeful that unusual individuals like this one and the neck-collared birds will allow me to track the daily movements of Canada geese resident in our area during the winter. My main goal this year, though, will be to see if the patterns I observed last year are repeated.

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