| There are signs of spring
in the North. Although early February seems a little premature
for serious migration, formations of sandhill cranes have
been spotted in the lower Great Lakes, including in southern
Indiana and even a few bold Red-winged Blackbirds have been
seen north of the Ohio River.
You
probably know what a sandhill crane is, because of the wide publicity a small group of
cranes received last fall as they followed an ultralight airplane through Indiana on their
way to Florida. It is the largest bird most of us are likely to see, standing up to four
feet tall. Only the whooping crane tops the sandhill, and only by a few inches. However,
your chances of ever seeing a whooper are slim, considering the species is nearly extinct.
On the other hand, sandhills appear to be thriving. The International Crane
Foundation estimates there are 650,000 of them. One can see them passing overhead in
nearly every state during migrations, and those migrations are indicative of this hardy
birds tough nature. Sandhills winter primarily in Florida and Texas, but they breed
in Canada and Alaska. The northern plains states were major breeding areas in the past,
and some breeding still occurs there, especially in wet years.
There is a resident, non-migratory population of
sandhills in Florida, and they are considered a threatened
species. A bonded pair lives in my neighborhood near the
Withlacoochee River. They are among only 4,000 to 6,000
of the Florida subspecies.
The neighborhood cranes have been resident for over three years and are seen
and heard daily throughout the subdivision. This pair is habituated to humans, owing to
the fact that they spend most of their days foraging on the local golf course and in our
yards.
One pair of resident cranes got in trouble here last week.
Wildlife officials received a call from a man who reported a crane was repeatedly
attacking the windows and screens of his home. The crane began attacking windows last
October and is still at it.
A state biologist explained that the male crane was interpreting it reflection
as another male crane, competing for a territory and for his mate. The biologist is going
to try and trap them, band them, fit them with transmitters and turn them loose. He
explained that transporting the birds to a distant location would probably not keep them
from returning, because of the cranes "keen sense of direction." He hoped
the experience of being trapped, banded and held for 30 minutes will be enough to
discourage this pair.
In general, all cranes are very aggressive, according to the International
Crane Foundation: "When fighting, they leap into the air to rake opponents with their
sharp claws or stab at an opponent with their bill. This continues until one bird runs or
flies away, sometimes closely pursued by the victorious bird. Fighting is dangerous to
both participants, however, so cranes use a complex system of threat behaviors allowing
rivals to avoid fighting. Communication includes both physical postures and
vocalizations."
That keen sense of direction and fearless demeanor are musts for the migratory
sandhills who must brave ice and snow on their early return flights. Some go all the way
to the edge of the Arctic Circle. They can fly at 52 m.p.h. but prefer to soar at
altitudes of 3,000 to 5,000 feet in North America.
During migration, large numbers of these birds drop into resting and staging
areas every spring and fall. One of the main staging areas is in northern Indiana.
"Staging areas of some species are traditional resting spots that have
been used for hundreds and possibly thousands of years. Examples of staging areas used by
sandhills include the Platte River (Nebraska), Jasper-Pulaski State Wildlife Area
(Indiana), and the Sandhill Wildlife Demonstration Area (Wisconsin)," says the crane
foundation, http://www.savingcranes.org/
Sandhills put on impressive displays at Jasper-Pulaski. It is
common to see spring courtship rituals performed by hundreds, sometimes thousands of birds
there every spring. Crane courtship is very athletic. Cranes will jump and flap, bow and
vocalize. They toss grass into the air and run with their wings extended. They are very
vocal and very loud.
Among the odd behaviors seen in sandhill cranes is something called
"painting." As described by the crane foundation: "Sandhill cranes and
Eurasian cranes paint themselves by preening mud into their feathers prior to
the breeding season. Painting acts as camouflage, helping the cranes hide amid the brown
vegetation of an early spring marsh."
Sandhills and other cranes are monogamous and live to be 25 to 35 years old in
the wild. The female typically lays 2 eggs a year and, also typically, only one offspring
survives. Cranes do not reach sexual maturity until they are between three and seven years
old. The pair shares incubation and feeding chores, although the male usually guards at
night while the female takes over incubation.
Sandhill nests are massive piles of sticks, moss and aquatic vegetation piled
high enough to keep eggs out of the preferred marshy habitat. Crane territories range from
a few acres to over 50 acres, depending upon food availability and other factors. They eat
literally everything, from crayfish to mice to insects to grasses and other vegetation.
If you get a chance to watch the cranes at Jasper-Pulaski this year, you
wont be sorry. Keep in mind that the birds will be there when the weather is still
raw and dress accordingly.
From Hoosier Times, Feb. 18, 2001
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