Peregrine Falcon
Commonwealth of Massachusetts
Division of Fisheries & Wildlife
Route 135
Westborough, MA 01581
Phone: (508) 389-6360 Fax: (508) 389-7891
www.nhesp.org
Peregrine Falcon
Falco peregrinus
State Status: Endangered
Federal Status: None
DESCRIPTION: The Peregrine Falcon is the fastest bird on earth,
capable of diving from great heights at speeds of up to 200 miles per hour.
It is a beautiful raptor with long, pointed wings and a long, slightly
rounded tail. Adults have a bluish-gray to slate-gray backside and a buffy
white underside interspersed with black. Adults also possess a black
crown, black moustache-like markings or “sideburns”, a white throat, a
dark bill with a prominent yellow fleshy base (or cere), and yellow legs
and feet. Immature Peregrines have a brown backside and heavily streaked
underside. Peregrines are medium-size falcons; males are slightly smaller
than a crow 0.4 to 0.45 m (15 to 18 inches) in length with a wingspan of
0.9 to 1.1 m (35 to 42 inches), while females are slightly larger than a
Illustration by Frank Taylor, from the
crow, reaching a length of 0.45 to 0.5 m (18 to 20 inches) with a
Raptor Research and Rehabilitation
wingspan of 1.1 to 1.2 m (42 to 48 inches).
Program pamphlet 1988
SIMILAR SPECIES IN MASSACHUSETTS: Most incorrect
reports turn out to be Cooper’s Hawks which are in the group of raptors (birds of prey) called
Acciptors. Birds in this group have long tails and short-rounded wings for dodging through the
maze of branches in forest habitats. The confusion comes from their being very similar in size to
the Peregrine Falcon, and from the fact that adults have a blue-gray back which is very similar to
the Peregrine. Cooper’s Hawks frequently take songbirds from backyard feeders, so they are
often seen at close range in suburban yards. Peregrine Falcons would almost never be seen in
these areas.
In the fall and winter, especially along the coast, smaller Merlins and larger Gyrfalcons may be
confused with Peregrine Falcons.
HABITAT IN MASSACHUSETTS: Peregrine Falcons in Massachusetts utilize artificial
nesting platforms high up on tall buildings in heavily urbanized areas (Amherst, Boston, Fall
River, Lawrence, Lowell, Springfield, and Worcester). Historical Peregrine nesting sites (eyries)
within Massachusetts were located on rocky cliffs. Of the 14 historical cliff nest sites, Peregrines
currently nest on Mount Tom and Mount Sugarloaf in the Connecticut River Valley. In general,
Peregrine falcons prefer to nest on cliffs or man-made structures overlooking a body of water.
Other man-made structures utilized for nesting in Massachusetts include the Braga Bridge (I-
195) in Fall River, the Goliath Crane in the Quincy Shipyard, and the control tower at Logan
Airport.
RANGE: The Peregrine Falcon is one of the most widely distributed birds in the world,
inhabiting every continent except Antarctica.
Nesting Distribution in Massachusetts
1987-2007
Based on records in Natural Heritage Database
LIFE CYCLE/BEHAVIOR:
Most Peregrine Falcons first
nest at 2 or 3 years old, but a few (particularly males) will breed as one-year-old birds when they
are still in their juvenile plumage. Once established, the adults will remain in the same territory
year-round. Adults generally live about 10 years. The longest known life span of a Peregrine
Falcon in Massachusetts was achieved by the second male to occupy the Customs House tower
territory in downtown Boston. This bird lived to be 17 years old and raised 50 chicks. Although
this pair nested on the Customs House in most years, they also nested on the MacCormack Post
Office and Courthouse Building in Post Office Square and in the 32nd floor balcony garden of the
Federal Reserve Bank. This illustrates the species’ tendency to nest in the same spot year after
year, but to occupy alternate nest sites within their territory in some years.
By March 1st the adult pair has chosen their nest site for the season and are spending a lot of time
in and around the nest site. Four, and rarely 5, eggs are laid around the beginning of April and
the chicks hatch in early May after a 28 day incubation. The chicks fledge (leave the nest) at
about 7 weeks of age in mid-June and become independent of their parents by the beginning of
August. In their first fall and winter most of the young falcons disperse to other areas of
Massachusetts, particularly along the coast, while others disperse throughout the Northeastern
states where they will eventually nest. A very small number of young birds will migrate as far
south as Florida, but will return to the Northeast again in the spring and never migrate south
again. Peregrine Falcons that nest at high latitudes in Greenland and Labrador migrate every
winter, going as far south as South America.
Peregrines are specially adapted to capture birds in flight. Their best known hunting strategy is to
soar up high over their territory and wait for a bird to fly past far below. Once a target has been
chosen, they do several strong wing beats to pick up speed and drop straight down into a
controlled dive called a stoop. It is during this maneuver that they can attain speeds of at least
185 miles per hour and approaching 200 miles per hour by some reports. The small bird flying
below does not usually even know that it has been targeted. The Peregrine will strike its prey
hard enough to kill it and streak right past. The falcon then pulls out of its dive and catches the
falling prey. It is a spectacular scene to watch and is what has made the Peregrine Falcon so
prized in falconry since medieval times.
In Massachusetts, the most frequent prey species are Blue Jay, European Starling and Rock Dove
(pigeon). Other common prey species include: Red-winged Blackbird, Common Grackle,
American Robin, Mourning Dove, Common Flicker, Chimney Swift, House Finch, Cedar
Waxwing, and Woodcock.
POPULATION STATUS: In the 1930s and 1940s there were probably about 375 nesting pairs
east of the Mississippi River in the United States. Fourteen pairs nested on cliffs in
Massachusetts. In 1948 the Massachusetts State Ornithologist, Archie Hagar, discovered that the
pair nesting on Rattlesnake Ledge on the western shore of the Prescott Peninsula on the newly
created Quabbin Reservoir had broken their eggs for no apparent reason. This observation was
the first indication of the affects of the pesticide DDT. Intended for the control of agricultural
insect pests, this pesticide passed up the food chain from insects through song birds to Peregrine
Falcons, and other predatory species, where it became concentrated. The most significant impact
to the falcons was that they laid thin-shelled eggs that broke under the weight of incubation,
leaving no young to replace the adults when they eventually died. By 1966, not a single nesting
pair remained in the eastern United States. The last historically active nest in Massachusetts was
on Monument Mountain in Great Barrington in 1955.
With the ban of DDT in the U.S. in 1972, the stage was set for restoration efforts to begin. The
Peregrine Fund, a non-profit organization originally based at Cornell University in New York,
began to captive breed and release young Peregrine Falcon chicks. Two of the earliest release
sites were on a tower at Mass Audubon’s Drumlin Farm in Lincoln (1975) and on the cliffs of
Mount Tom in Holyoke (1976-1979). Unfortunately, none of these birds survived to breed. With
the creation of the “Nongame and Endangered Species Program” in 1983, funded largely by
voluntary donations on the state income tax form, Peregrine Falcon restoration became the
Program’s first new project. Young falcons were released on the roof of the McCormack Post
Office and Court House Building in downtown Boston in 1984 and 1985. This effort led to the
first modern Massachusetts nest in 1987.
Eventually, more than 6,000 captive-born Peregrine Falcon chicks were released across the
country by several organizations. The number of nesting pairs continued to grow to the point that
on August 25, 1999 the Peregrine Falcon was officially removed from the federal list of
Endangered and Threatened Species, having skipped the status of Threatened. Recent surveys
have documented over 2,000 nesting pairs in the U.S. (2002), over 400 in Canada (2002) and
about 170 in Mexico (1995). In Massachusetts, there were 14 known territorial pairs in 2007.
This was the first year that the numbers of pairs had returned to their pre-DDT levels.
Updated:December 2007
