30, 2003 Commentary: The
observations in this commentary are based on my observations and
experiences as a volunteer for the Osprey Introduction Program at
Tioga-Hammond Lakes, Tioga, PA (and later by osprey choice at the
Cowanesque Lake, Lawrenceville, PA) during three summers of the
5-year project and during several follow-up years. Dennis Puleston's
influence is the reason for my family's interest and involvement
in this project and for our support of the Dennis Puleston Osprey
Fund. More details about our connection with Dennis are related
in an article entitled "Remembering
Dennis" in the Spring 2003 issue of the Post-Morrow Newsletter,
also available at the corresponding link on the Homepage of this
Status of the Osprey
Mike Scheibel, Wildlife Manager for the Nature Conservancy's
Mashomack Preserve on Shelter Island:
(like other raptors found in NY) are protected by both state
and federal law. In addition to the legal protection afforded
most native avians in NY, the osprey was listed in or about
1976 on NY's first endangered species list.
additional layer of protection increases fines and other
penalties for harassment, take, etc., but perhaps more importantly
opens funding channels for management activities associated
with recovery strategies. Due to the ospreys' dramatic recovery
in NY over the past quarter century, DEC has down-listed
this species to "threatened" and then "special
The level of legal protection has not decreased, but rather
the down-listing reflects the less critical population status
of the species in NY.
— Marilyn Porto Abbey (Retired teacher; osprey watcher)
through 1994, biologists worked in co-operation with the Army
Corps of Engineers and with the support of volunteers to establish
an inland breeding population of ospreys near the South-central
border of NYS and the North/central border of PA. The project
used a technique called "hacking" developed by Dr. Charles
Schaadt, Penn State University and Dr. Larry Rymon, East Stroudsburg
University. Hacking involves the process of removing young osprey
chicks from "donor" nests and raising them in a tower
in enclosed artificial nests at the reintroduction site. Near
the time of expected fledging, the enclosure screen is lowered
to form a platform from which the young ospreys are free to fly
when they are ready. Volunteers assist in weighing, banding, reporting
observations, feeding the chicks their normal diet of fish until
the birds are fishing successfully on their own. The ospreys become
imprinted on the area, migrate in the fall to Central or South
America and return from their wintering grounds in 1&1/2 yrs.,
when they are mature.
Take-Offs: A remarkable incident at a Hammond Lake Hacking
Tower, Tioga, PA, summer 1993. This incident demonstrates the
amazing skill of young ospreys: One of our ospreys was standing
on the edge of the tower platform exercising her wings. At one
point, she lifted off about 6 inches and was watching her dangling
feet when a gust of wind came and tumbled her backwards off the
platform. At about 3-4 feet off the ground, she flapped her wings
and righted herself. She arched around in a most graceful flight
and landed in a dead tree about 100 yards away, as though she
had been doing it for years!
Concern: There has been some concern about the belief of
some people that the female osprey won't return to the nest to
feed the chicks if humans go near the nest or disturb the chicks
in any way.
Unlike condors and vultures, ospreys can't smell worth a darn,
so human scent is not an issue here. Maybe that's how they can
ignore the smell of decaying fish parts after so many fish meals
have been served in one place!
Here is an eye-witness account: The scene is the
first natural nest in our area, built by a pair of ospreys, on
a dead tree in Cowanesque Lake, Lawrenceville, PA. in 1994. The
biologists/naturalists approached the nest by pontoon boat. The
purpose was to band the chicks for research (tracking, survivors,
returnees, etc.) The adult female flew off the nest and the male
soon joined her flying around overhead. The three chicks were
banded in approximately 20 minutes, and from the time we left,
the female parent was back on the nest in 20 seconds. They did
scold us, but they never tried to attack us, and our interruption
didn't discourage them from coming back in a flash! The chicks
thrived and lived to fledge and fish on their own. The ospreys
have returned to that same nest for nine years and have raised
a total of 27 healthy chicks.
Asked Questions about Ospreys
Hatching to fledging: 7-8 weeks
Average weight: 3.1 lbs. (Females slightly bigger/heavier)
Wing span: 4 1/2 Ft. to 6 Ft.
Number of eggs per season: usually 2 the first year and
3 every year after the first.
FAQ: As the chicks get older and can be left alone for
longer periods of time, does the mother ever go out and catch
any fish for them? Or is it only the father that goes for food?
A: Osprey chicks are left alone for longer periods of time
as they get older. (Eagles do it too,.... small birds, too). The
female does most of the feeding especially when the chicks are
young. It would be too risky to leave them alone until they are
much larger. At this point in the chicks' development we have
watched the female osprey wait and call for the male to come back
and when he didn't, she would finally leave the nest and do the
fishing herself. She would eat a little herself and then feed
the chicks. I have also seen the male come to the nest "empty-taloned,"
watch the female leave to go fishing and then take over the incubating
or "chick sitting" while she is gone. The male does
help with the feeding as the chicks get older and after the chicks
fledge, they still depend on both parents for food, sometimes
for as long as 4-8 more weeks. Normally, the male does most of
the fishing and delivery of meals and he is an expert at it.
at this nest Submitted by Dave Shore:
arrive March 23, begin fixing nest and doing their spring ritual
of he feeds her, she submits to copulation, they both build on
egg is laid April 8, second April 11, third April 15, fourth and
last on April 18. Both adults take turns sitting on the eggs.
hatches on May 17 at approximately 7:00 AM. Male stops sitting
on chick and eggs, female assumes full duty, male supplies fish.
hatches May 17 at approximately 6:00 PM, the third hatches May
20 around 1:00 PM and the fourth on May 24 around 6:00 AM. Fourth
chick only survives a few hours, the weather was cool and very
all three remaining chicks got fed regularly. Starting on May
25, the older, bigger two chicks began their aggression against
the younger third chick. They would take turns pecking and blocking
the chick from feeding until they had eaten themselves to sleep.
As time passes the aggression becomes more frequent and severe.
in June, the by now much smaller third chick is regularly kept
from feeding. The pecking and pushing are more severe and the
third chick is forced to lay still while the other two feed. If
there is anything left when the older chicks are done, the female
feeds it to the third chick.
By June 11,
the third chick is no longer getting fed, or very little. It
dies sometime on June 13, but remains in the nest until the next
day. We are trying to figure out how it was removed by reviewing
June 14, the
remaining two chicks begin aggression against each other, they
stand and stretch their necks and wings and then peck. The dominant
one then would get behind the other and herd it to the edge of
the nest where it is forced to lay with it's head down. The dominant
one then eats until satisfied and the other gets what is left.
The adults show no sign of intervening. Both chicks are about
the same size and have lots of feathers coming in. They will stand
facing the wind and flap their fuzzy wings, stretching and exercising.
They also are very vocal, calling out like the hen when she is
calling the male.
June 27, the chicks were observed practicing takeoffs by facing
into the wind, flapping their wings and hopping into the air a
few inches, then landing back in the nest. The chicks have also
become very vocal. They sound like the adults, although not quite