Wednesday 25 March 2015

Why do some Geese have rust coloured markings ?

March 20 2015 Ladner BC Overcast with sunny breaks 11c

Snow Goose (Chen caerulescens)
The rufous heads are the result of these birds foraging in the iron rich soils of Washington State. This flock of about three hundred birds were photographed in Ladner.

The bird in the foreground has far less colouring, perhaps feeding in a different area and then joining this flock for the northward migration.

A hungry Coyote (Canus latrans) contemplates his next move.
I have included a shot below taken on their southward migration to show the Blue morph variety of the Snow Goose.

Adult dark morph Snow Goose with 'regulars'
This shows a large congregation of Snow Geese preparing to leave on their northward flight to Wrangel Island, Alaska.

Since this last picture (below) was taken in 2009 their population has almost doubled and their breeding grounds are not going to able to support their presence. A population crash is inevitable at some time. I recently returned from Churchill Manitoba where research group say large swaths of tundra have stripped bare by the geese.
Thousands of Snow Geese and Reifel Migratory Bird Sanctuary just outside Vancouver.
       Around Reifel Migratory Bird Sanctuary winter crops are sown to provide migrating Geese and other birds access to forage on their migration.

If anyone can provide a detailed explanation about the rust coloured stains on the Snow Geese I will gladly publish it here with a full credit, thanks.

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"It's never too late too start birding"

John Gordon
BC Canada

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