I have fond memories of spending two two-week periods of my
first summer vacations from teaching as a student at the
Wisconsin Audubon Camp in the northwestern part of the state.
One of my favorite leaders was Dorothy Treat, a full-time staff
person with the National Audubon Society, who was an excellent
interpretive naturalist and outstanding nature-study teacher.
A concept she strongly stressed was the good word
"BON," Balance Of Nature. Fortunately I was able to
use many of her techniques in my own classroom and nature center
teaching. As the years went by I began to realize that the more
populated our Earth became the more difficult it was to find
areas reflecting really good balances of nature. Ordinarily one
assumes that an increase of any animal is usually followed by a
relative increase of its natural enemies. Sadly such is not the
case today in many parts of the world.
I think of one particular bird of prey, the red-tailed hawk,
and here is a perfect example of the innocent suffering for the
guilty. It has been common practice for many years to kill these
raptors, out of pure ignorance, thinking that they are guilty of
taking poultry or other small game animals when in a great
majority of the time this is not the case. You kill the
red-tails, the rodent population rises and there goes the balance
of nature. Fortunately all birds of prey in Wisconsin, and in
other states as well, are protected by law today. Sadly,
however, far too many red-tails were killed before good laws were
passed.
Red-tailed hawks could appropriately be called one of the
leading members of nature’s sanitary corps. Around 65% of their
diet consists of mammals considered to be injurious to
agriculture. Not more than 7% of their food consists of poultry,
very likely old, diseased and disabled fowls. What a wide
variety of wild mammals they are known to prey upon including
shrews, gophers, skunks, raccoons, muskrats, porcupines, rabbits,
weasels, mice, rats, chipmunks, squirrels, snakes, toads and
insects. Young red-tails in the nest are fed largely a diet of
squirrels and mice.
It was during the past few winters, at least the early
portions of them when there was little to no snow cover, that we
observed so many red-tailed hawks throughout the countryside
usually perched on dead or bare trees or on power poles,
patiently waiting for their prey to make a move. Presumably
some of these birds were northern red-tails that found good
hunting and remained in the area until the snow cover became too
thick, then moved southward.
The other bird of prey often confused here in winter with the
red-tail is the rough-legged hawk. As soon as this raptor takes
to the air you usually can make out its distinctly dark wrist
makings on its lower wing surfaces and also the large white rump
patch. Actually the bases of the bird’s tail feathers are white
making it appear from a distance as a rump patch.
Should an adult red-tail in flight give you a good look at the
upper surface of its tail, as the bird banks, it is then that its
real trademark shows up so nicely, its brick-red tail. Seen from
below, the bird’s tail is actually quite white. The red feature
is acquired after midsummer of its second year. First-year
red-tails do not have red tails. Any buteo (BYOU-tee-o) in
flight usually has its short wide tail fully extended. This in
itself can be a very good field mark to observe.
In general the red-tailed hawk is dark brown above, has a
white throat, dark spotted band (not solid) across the breast,
then a large white area, a faint band of dark markings across the
belly, and then white to the tip of the underside of the tail.
Come summer, a red-tail in flight is quite easy to identify,
even from a distance, by its sheer size. Only ospreys and bald
eagles top them in size in our state. The rough-legged hawks,
comparable in size, having flown to their far northern breeding
grounds, are nowhere to be seen in Wisconsin in summer.
Red-tails are thought to mate for life. Their courtship and
nesting begin by the end of March and into early April. These
birds prefer open farmland bordered by mature woods and
frequently build their nests as high as 35-70 feet up in a large
tree. The three-foot-wide structure is made of sticks and twigs
half an inch or less thick, and the nest is then often lined with
strips of inner bark of, for example, cedar trees.
Finally the nest is adorned with several sprigs of fresh green
pine, cedar or hemlock. Close observations indicate that the
adults rarely miss a day during the nesting period of adding a
new evergreen bough. The young are known to pull the green
boughs over themselves, perhaps to be shielded from the hot sun
as well as from possible predators.
It was from Fran Hamerstrom, expert researcher and handler of
raptors, very knowledgeable about the ways of predatory birds,
that I learned that a parent red-tailed female will tear off bits
of meat half the size of a pea from its prey, moistened by its
own saliva, and very meticulously feed this to the small babies
in the nest. Even before the young have grown their own feathers
they already are capable of tearing up their own food.
While in the nest, the young void their excrement in long
streams over the edge of the nest. The ground below the nest
becomes quite liberally marked in white by the babies’
"calling cards" they have dropped – quite an unusual
way to prevent the nest from becoming soiled!
It’s not uncommon to see where a great horned owl has used an
old red-tailed hawk nest from a previous year in which to raise
its young. These two species, the red-tail hawk and the great
horned owl, exist quite nicely in the same general area as
supplementary species, both feeding generally on the same prey
species. One is the day-hunter while the other hunts at night,
an excellent example of partners in nature.
I hope you get a chance to enjoy a large red-tailed hawk on a
lazy summer day on set wings cutting circles high in the sky as
it searches the ground below for its next meal.
Chances are good that the large hawk you may see on a
lazy summer day, on set wings, high in the sky, is a red-tailed hawk.
This permanantly injured adult red-tail is part of the education program
at Milwaukee's Schlitz Audubon Nature Center.
This column appeared in the Door County Advocate
on 04/17/2004.
© Copyright 2004 Roy Lukes. All rights reserved.
