| Transcript |
ARTICLES
WEST HARRIS COUNTY - FEBRUARY 24
OG WEEKDAY FIELD TRIP REPORT
by Gail Diane Luckner
Nineteen birders gathered at Bear Creek Park to begin a
"caravan-style" field trip through west Harrk County in
search of sparrows, raptors and waterfowl. Although the
cloudy, cool, very windy day yielded very few raptors, ten
species of sparrows were found, including excellent looks at
several Harrk' Sparrow in various plumages, a lifer for two
members of the group. Side-by-side Field and Chipping
Sparrow allowed Winnie and I to point out the key field
marks of these two species which some birders find
confusing. Ako obliging us were many White-crowned
Sparrow in both adult and immature plumage, and several in
the group learned how to distinguish these.
We found nine species of waterfowl, including Snow,
Canada and White-fronted Goose. Despite close looks at
hundreds of Snows, we were unable to spot a Ross' among
them. We did flush large numbers of Common Snipe from
nearly every field where we stopped. A lovely Black-
shouldered Kite turned out to be the raptor highlight of the
day.
The trip ended a little after 11:00 a.m. By then, the
wind was blowing so hard it was difficult to hold our scopes
and binoculars steady. We ended with 55 species for the
day. Weekday field trip regular Al Clarke once again made
the drive from Lake Jackson to join the outing.
RABBITS BEWARE!
Some Birds of Prey Hunt in Packs
by William K Stevens
[Reprinted from The New York Times, January 19,1993.]
The majestic image of the lone eagle may often hold true.
But scientists are ako beginning to piece together a more
complex picture of eagles, hawks and falcons as team players
whose hunting tactics and cunning intelligence invite
comparison with the wolf and the fox.
Eagles, in fact, not only mount concerted and
successful attacks on the fox itself; they ako deceive
monkeys, humans' close relatives, in a deadly game of
predator versus prey. By acting together, they are even able
to bring down big animak like deer, antelopes and African
bushbucks.
Diving, swooping and executing barrel rolls,
peregrine falcons double-team rapidly darting swifts, birds
that no single falcon could possibly outmaneuver. As the
swift veers right and left in a horizontal plane, both male and
female come at it from above. The male, smaller and more
agile, reverses course once it k below the swift and attacks
a second time, from beneath. The multiple assaults drive
swifts to such dktraction that they fly into obstructions or
plunge into water, becoming easy pickings.
And in the Southwest, family groups of Harris's
hawks assemble each winter morning, divide into platoons
and scour the countryside for rabbits. When one k found,
the platoons converge and go on the attack. If necessary,
one platoon flushes the prey from brush directly into the
talons of the other. If a speedy jack rabbit leads them on a
chase, the hawks pursue in relays that keep the quarry
running till it drops.
These hawks are "not one whit behind a wolf pack"
in their hunting behavior, said Dr. David H. EUk, an animal
behaviorkt and raptor expert at the Patuxent Wildlife
Research Center of the U.S. Fkh and Wildlife Service at
Laurel, Md.
As the grimly fascinating evidence accumulates it k
forcing scientists to reassess their longstanding treatment of
raptors as solitary predators. Often the birds do hunt alone,
and the difficulty of observing them at work has made it
hard to dkcover other kinds of hunting behavior.
But now, according to a study in the current issue of
the journal BioScience, there are enough observations to
suggest that eagles and their cousins command a wide
repertory of predatory actions, including the most
sophisticated. Thk command may be essential to the
species' long-term evolutionary survival strategy.
Raptors' newly appreciated prowess reveals "a high
degree of intelligence," said Dr. Ellis, the primary author of
the paper in BioScience.. Just how bright raptors are relative
to the intelligent mammak they kill is unclear and a subject
of future research. But in any case, the catalogue of
behavior culled by Dr. Ellk and hk colleagues from the
scientific literature adds up to a chilling picture of raptor
craftiness.
Some hunting hawks travel with similar birds, like
vultures, to dkguke their presence from the prey. A number
of raptors follow the leading edges of fires, rising flood
waters, moving trains and even people to capture prey
flushed by the disturbances. Peregrine falcons have
accompanied a moving train for up to six miles for thk
purpose.
Gyrfalcons in Alaska often followed a trapper to
catch ptarmigans, birds that he flushed while tending hk
traps. In an extreme example, a northern harrier prowled an
active bombing range to nab animak and birds scattered by
|
