Biology Reference
In-Depth Information
Great Blue Heron. (Richard Bohnet)
where their prey tend to concentrate, or anywhere fish might be swim-
ming by. Once they get there, they're pretty patient. You watch them and
they'll stand for long periods of time and nothing will happen, and all of a
sudden they'll pull up something really big. I opened up a dead Great Blue
Heron once that had a 14-inch Sacramento Sucker occupying most of its
insides. They're generalist feeders. Whatever they can cram into their
beak, they will.”
Kelly says herons are also primarily solitary feeders, and they can be
quite territorial about their feeding grounds. He's seen herons chasing
each other away on the ground, and even engaging in full-body blows to
protect their foraging turf. Kelly estimates that, on average, the San Fran-
cisco Bay area supports at least 500 pairs of Great Blue Herons, nesting in
at least 62 colony sites.
Though not nearly as tall and slim as great blues, Black-crowned Night
Herons are also fearsome fishing birds and predators (see cover inset
photo). These black, white, and grey herons live and nest around the bay,
especially on Alcatraz Island. They come out to hunt at dusk, dawn, and
through the night, preying on fish, insects, crabs, and amphibians. They
have even been known to eat other birds. A South Bay birdwatcher once
watched a couple of Night Herons make a meal of six Gadwall Ducklings
in the South Bay. A copycat Western Gull made 17 similar attempts, with
no success.
Peeps
The most diminutive of the bay's shorebirds are the “peeps,” small sand-
pipers that can be difficult to tell apart. The peeps of San Francisco Bay
