Every April the flock managers
of the five
facilities in North America that breed Whooping Cranes get together
phone calls to share information about egg production.
These folks and their staffs (maybe 40 people overall) are
responsible for caring for the 148 Whooping Cranes currently
Timing is Everything
Cranes start laying eggs as early as April in southern captive locations,
such as New Orleans, Louisiana and San Antonio,
Texas. In the north, egg laying generally takes place later.
It extends into June, equivalent to the timing of the wild
Cranes in Canada. Cranes respond to (1) temperature and
(2) day length (photoperiod) to
their time of breeding to the climate.
Disappointing Year for Egg Production
are these precious eggs
kept safe when they are shipped? Read
Mark Nipper, WCEP
year, the egg laying has been a disappointment. The egg laying
has been slow. Some eggs were infertile. Other eggs have
been broken by the parents. The
captive cranes at Calgary did not follow "the rules" and
laid a few eggs quite early. At one point,
all the eggs had to be taken from the Calgary cranes because
of a snowstorm and very cold temperatures. These conditions
would have threatened the eggs if one of the adults stopped
even a short time. All the eggs were placed in an incubator
where the storm could not affect them.
the eggs from the Whooping Cranes when they are laid results in
the female crane then laying
a second or even a third clutch of eggs. Since most clutches
two eggs, one female in captivity can be coaxed to lay about
every year. Both
the male and female Whooping Cranes take turns sitting on the eggs.
This teamwork allows one adult always to be out getting food
to eat. Taking turns makes it less stressful for the adults
to sit on the eggs for 29-30 days until they hatch.
April 30: Count of Possibly Fertile Eggs
Wildlife Research Center
Crane Foundation (fertility unknown at this date)
An Enormous Challenge
is very, very hard to successfully get Whooping
Cranes to breed. Of the 15 species of cranes in the world, I think Whooping
Cranes are the hardest to breed. I am very worried that we will not have
chicks this year to meet our target of releasing about 30 whooping cranes
into the wild population
that migrates between Wisconsin and Florida. The flock managers
are doing everything they can to have a successful production year.
But ultimately it's up to the captive cranes to decide if they are
going to have a good year or a bad year producing eggs. So far, I'm afraid
like it might
be a mediocre-to-bad production year. Keep your fingers crossed for
better luck in the weeks ahead. I guarantee that we've got 40 people
possibly can to help the cranes produce young this year.
Aransas National Wildlife Refuge