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This afternoon I checked the two Great Blue
Heron rookeries on both branches of the South Fork of the Ogden River
in Ogden Valley. The trees lining both branches of the river are
mature, very woody, and offer great habitat for big birds that build big
nests.
Many herons have claimed nesting sites. A few
of the bird-condominiums could still post 'Vacancy' signs.
From my vantage point, it looked like one
dead tree in particular sported five nests at a height of 60-70 feet.
Two of the five nests were vacant. Two were occupied by Great Blue
Herons. And the final one was occupied by...no, not a Red-tailed or
Swainson's Hawk...no, not a Double-crested Cormorant...and no, not a Great
Horned Owl. The big bird comfortably settled on the nest was a Canada
Goose, sitting beak-to-beak with the herons up in the penthouse
apartments. I was unprepared for the sight and it took a minute for
the long black neck and white cheek patch to register. Of course, it was
not just any old Canada Goose, it was obviously a silly goose!
The goose's choice of nest sites is a far cry
from a grassy hillock at water's edge or a nesting platform outfitted with a hay
bale. And just think of the hazards those precocial, newly-hatched
goslings will have to negotiate! They could become breakfast in
the sword mandibles of their neighbors. If that hazard doesn't get
'em, think of their first 60-foot step out into the wide, wide
world. It's a good thing our kids don't have to take such a big leap
when they're ready to leave the nest!
I reviewed the Canada Goose species account in
Kaufman's Lives of North American Birds to see if this particular nest
site selection was described. "...always nests near
water." Well, the water IS only 60-70 feet away.
"Nest: Site (probably chosen by female) is usually on slightly elevated
dry ground near water, with good visibility." Yes, the
site IS elevated, dry, and it certainly has good visibility!
"Much variation; may nest on cliff ledges, on muskrat houses, in trees, on
artificial platforms." There we go...in trees! And finally,
from Kaufman, a hint that the gander of this pair is going to have to
become a passerine, or perching bird: "Incubation is by female, 25-28 days;
male stands guard nearby."
Kris
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