CURRENT STATUS: Pennsylvania, endangered; Migratory Bird of Management Concern in the Northeast
POPULATION TREND: Black terns (Childonias Niger) have declined in numbers both during migration
and at the few nesting sites known in Pennsylvania. The breed annually only in Crawford County and have nested in recent years
at Presque Isle State Park in Erie County. Black terns have been a species of concern in North America because of continent-wide
population declines, particularly since the 1960s. Currently the species is listed as threatened or endangered in six states
and is considered of conservation concern in 18 other states and provinces. Breeding bird surveys show black terns declined
significantly in North America at an average rate of about three percent annually (61 percent overall) from 1966 to 1996.
These declines largely reflect trends prior to 1980, and trends in the Prairie Potholes were reversed in the 1990s. The North
American population recently has leveled off or increased slightly. The species still occupies most of its former range, and
the continent-wide breeding population probably still numbers in the low to mid hundreds of thousands. The black tern was
listed as a threatened species since 1985; it was designated an endangered species in 1990.
IDENTIFYING CHARACTERISTICS: Terns are slender, graceful fliers with long pointed wings.
They are often associated with coastal environments, but the black tern is found inland. During the breeding season this bird
is relatively easy to identify because it is the only all-black tern. In the fall, juveniles and molting adults have black
and white mottled plumages. Flashing light underwing linings make the black tern especially conspicuous in flight.
BIOLOGY-NATURAL HISTORY: Black terns nest across the northern United States and southern Canada, and winter
in South America. They are regularly seen migrating through Pennsylvania, appearing in April and May, and then again in August.
Nonbreeding adults can be found here in the summers, but Pennsylvania’s northwest corner is the only place in the state
where they nest. This area represents the southeast extreme in the species’ breeding range. These terns build fragile
cup-shaped nests in reeds or on floating masses of dead plants, just above the water. A typical clutch consists of three olive
or buff-brown marked eggs. Young hatch in three weeks, and first fly at three or four weeks of age. Black terns are primarily
insectivorous, snatching up insects in flight. They also eat small fish and crustaceans which they pluck from the water surface.
PREFERRED HABITAT: Black terns leave coastal areas behind and come inland to nest in prairies
and in the more extensive deep-water marshes or marsh complexes with extensive cattail beds. Winter finds them back along
the coast, often with other terns.
REASONS FOR BEING ENDANGERED: As black tern nesting colonies here are small and localized,
they are extremely susceptible to both man-caused and natural disasters. In addition, the number of black terns nesting here
has been declining over recent years. The main causes of population declines in North America appear to be habitat loss and
degradation on the breeding grounds, although introduced species, human disturbance, and contaminants may be contributing
factors. Since the 1950s, the freshwater emergent wetlands upon which the species depends for breeding have declined by 25
percent. Very little is known, however, about threats to the Black Tern during migration and winter, which account for eight
to nine months of the species' annual cycle.
MANAGEMENT PROGRAMS: Pennsylvania’s black terns must be monitored annually. After
it’s learned where and how many black terns are nesting here, measures may be taken to protect and expand their natural
habitat. But, as Pennsylvania lies on the margin of this species’ breeding range, the birds may not ever be found here
is significant numbers. Nationally, the recovery of Black Tern populations likely will require a combination of management
efforts and policy initiatives to improve habitat conditions and nesting success. Conservation priorities are (1.) refining
monitoring techniques to better detect population trends and determine the causes of changes; (2.) stemming the tide of wetland
loss by forming partnerships to protect and restore wetlands from a landscape perspective; (3.) managing habitat for Black
Terns based on current knowledge while conducting further research to identify limiting factors and evaluate additional management
techniques, and (4.) educating the public about the value of wetlands and possible effects of their actions on Black Terns
Least Shrew
CURRENT STATUS: In Pennsylvania, endangered; nationally, no special protection.
POPULATION TREND: The least shrew (Cryptotis Parvawas) thought to be widespread throughout
much of Pennsylvania, albeit mainly in localized populations, during the mid 1900s. During that period, surveys conducted
across the state by mammalogists found this mid-sized insectivore in every region of Pennsylvania except the north-central.
Recent surveys now suggest, however, the least shrew has disappeared from many of the sites where it was once present and
is now restricted to southeastern counties. Post 1970s surveys have found the least shrew at isolated sites within York and
Adams counties with possibly one of the most extensive populations occurring within the Eisenhower National Historic Site
near Gettysburg. Isolated populations may occur at other sites across Pennsylvania but remain in jeopardy of localized extinction
from myriad factors ranging from changing landscapes and land-use patterns to loss of habitat. The least shrew was listed
as endangered in 1990.
IDENTIFYING CHARACTERISTICS: The total length of the least shrew is from three to 3 ½ inches.
Its tail length ranges from ½ to ¾ inches, which is the shortest tail of all Pennsylvania shrews. It has a black to ash-gray
belly. The only other species of shrew with a short tail, the more common northern short-tailed shrew, is larger (total length
is four to five inches) and is dark slate-gray colored.
BIOLOGY-NATURAL HISTORY: The least shrew is found throughout much of the eastern United
States, ranging from New York south to Florida and through the midwest into Central America. A grassland species, the least
shrew is restricted to non-forested habitats that are free from grazing and intensive agricultural practices. Although much
of the biology of this species in Pennsylvania remains unknown, it is believed to have up to three litters per year, averaging
five young per litter, between March and November. Like other insectivores, they feed primarily on insects and their larva,
earthworms, spiders and sometimes snails. Several researchers have noted that the least shrew appears to be a colonial or
somewhat social shrew in forming nests occupied by several adults, rather than occurring singly. In Indiana, it is sometimes
referred to as the "bee mole" as it has been found to infrequently enter bee hives and feed on the brood.
PREFERRED HABITAT: Unlike other shrews, the least shrew prefers non-forested habitats. It
is often found in old sedge meadows and non-agricultural fields. Although the soil substrate of an area does not appear to
be important, this species occupies subsurface runways and uses areas where building such runways is easier. In many cases,
the areas where these shrews are found are in loose shales and non-compacted soils.
REASONS FOR BEING ENDANGERED: Intensive agricultural methods are practiced throughout much
of the least shrew’s former Pennsylvania range. In many areas, the use of rotation practices has lessened and untilled
or non-pastured fields are lacking. This coupled with the regeneration of forestlands and development of other lands has reduced
the amount of the least shrew’s preferred habitat. In many cases, where the habitat does exist, the populations remain
isolated, increasing the possibility of chance events leading to localized eradication of these populations.
MANAGEMENT PRACTICES: Management practices beneficial for the short-eared owl and other
grassland species should also benefit the least shrew. Surveys to find this species need to be intensified and populations
found should be protected. Habitat studies in the vicinity of known populations on public lands should be carried out before
any restoration efforts are planned.
Indiana Bat
CURRENT STATUS: In Pennsylvania, endangered; nationally, endangered.
POPULATION TREND: The Indiana bat (Myotis Sodalis) has largely declined throughout much
of its range because of disturbances to hibernacula during winter months. Distribution-wide populations have seen a decline
of 28 to 30 percent with individual state declines ranging from eight to more than 73 percent. Within Pennsylvania, the Indiana
bat is poorly represented, having occurred historically at only eight sites, all of which were natural caves. Recent surveys
have found the Indiana bat at two caves, five limestone mines and two coal mines. Although the trend for finding new locations
has improved, this may be because more complete surveys have been done and not that the Indiana bat population is increasing.
At sites that have been monitored over a number of years, populations remain low, but stable. The major cause of declines
in Indiana bat populations remains disturbance to winter hibernating populations and, in several cases, intentional vandalism
to the hibernating site and the bats.
IDENTIFYING CHARACTERISTICS: The Indiana bat is very difficult to distinguish from other
Myotis species. Three characteristics are generally used to identify the Indiana bat. Unlike the little brown bat, the Indiana
bat has a well developed keel on the calcar, a spur of cartilage leading off the foot and used to support the tail membrane.
The facial area of the Indiana bat also appears to be pink rather than black as in the other Myotis species, because of a
lack of hair around the nose and mouth region. Another feature that is very easy to use to identify the Indiana is the short
hairs on the foot which do not extend to the ends of the toes as they do on the little brown bat. When identifying these bats
in the field, it is best to use the suite of listed characteristics than only one or two because individuals differ markedly
across the range of this species.
BIOLOGY-NATURAL HISTORY: The Indiana bat occurs in the eastern United States from northern
Florida into New England and from the west in northeastern Oklahoma, Arkansas and much of Missouri into the central Mississippi
Valley. It does not occur along the Atlantic coastline. During hibernation, Indiana bats can be identified by the large, tightly
packed clusters they form on cave and mine ceilings and walls. Indiana bats, and other hibernating bats, are most susceptible
to disturbance during the winter months when they enter hibernation by lowering their respiration and body temperature. At
this time they only have enough energy reserves to last through winter and relatively few waking periods. Repeated disturbance
during winter could cause them to awaken in spring without enough energy to survive the cooler weather encountered upon leaving
the hibernacula.
PREFERRED HABITAT: Hibernation sites are usually cold with temperatures ranging between
42 to 45 degrees and generally have some standing or flowing water in them. Maternity colonies are most often found behind
flaking bark on dead or dying snags along stream or river corridors and frequently in upland forests. Females give birth to
only one young or, in very rare cases, twins. Only one litter is raised annually.
MANAGEMENT PRACTICES:The protection from disturbance of hibernation sites is the most important
factor in the conservation of this species. Historical and present sites should be gated during winter months to keep people
from coming into contact with hibernating populations of Indiana bats. Many historical sites remain unused by Indiana bats
and need to be further protected before the declines of this bat’s numbers can be halted. Only after these winter sites
are protected can we begin to address the question of protection of summer maternity habitat.
King Rail
CURRENT STATUS: In Pennsylvania, endangered; Migratory Bird of Management Concern in the
Northeast.
POPULATION TREND: The king rail (Rallus Elegans) has always been scarce in Pennsylvania.
Confirmed breeding/nesting has been restricted to two locations in the state since the 1980s. These areas are a marshy field
along Route 15 south of Lawrenceville in Tioga County, and State Game Lands 284 in Mercer County. Until the early 1990s, one
or two pairs nested in Philadelphia County’s Tinicum marshes, and nesting has been irregular at Crawford County’s
Conneaut Marsh. Additional surveys are required to determine the status of populations at known sites and in other areas with
appropriate habitat. It’s possible this bird no longer occurs regularly at any single location in the state, but little
is known of its habits in Pennsylvania. The king rail was designated an endangered species in 1985.
IDENTIFYING CHARACTERISTICS: The king rail is so named because of its large size and bright
coloration. This plump chicken-sized bird is a bright rusty color. They range from 15 to 19 inches in height and have 21-
to 25-inch wingspans. Males are larger than females. Bills are long, slightly decurved, and yellow with brown tips. These
birds are extremely secretive and would rather run than fly to escape detection. They are rarely seen, therefore, and are
most often located by their loud calls, a resonant grunting bup-bup, bup, bup, bup, more rapid at the end.
BIOLOGY-NATURAL HISTORY: King rail nests are platforms up to nine inches in diameter, six to 18 inches above
the water. They are built of grasses, sedges and cattails in shallow-water marshes and roadside ditches. From six to 15 pale,
slightly spotted brown eggs are laid in a shallow depression of the nest. Overhead cover is often pulled over the nest. Young
are able to fly about 60 days after hatching. Wading in shallow water, king rails feed on crustaceans, small fish, frogs and
insects. In winter, food items consist of grains – particularly rice – and berries.
PREFERRED HABITAT: This rail lives in freshwater and brackish marshes and roadside ditches
in eastern North America, primarily along the Atlantic coast. It is a very rare breeder in the few larger marshes remaining
in Pennsylvania.
REASONS FOR BEING ENDANGERED: King rails were never common in Pennsylvania, but annual reports
indicate the bird today is much less abundant than historically. This apparent decline is considered to be due primarily to
losses of marshland habitat.
MANAGEMENT PROGRAMS: As with many other endangered and threatened species, the king rail
needs wetlands in order to exist. Maintaining stable water levels during the summer will enhance the species’ breeding
success here.
Common Tern
CURRENT STATUS: In Pennsylvania, endangered; Migratory bird of management concern in the
Northeast.
POPULATION TREND: Common terns (Sterna Hirundo) are uncommon to fairly common regular migrants
over most of Pennsylvania; the greatest numbers are recorded along Lake Erie where they are fairly common to abundant. Non-breeding
birds are occasionally found on the Lake Erie shoreline in summer; they also are casual to accidental summer visitors elsewhere
in the commonwealth.
Common terns were never considered common nesters in eastern Pennsylvania, but at Presque Isle State Park,
up until the 1930s, scores nested in a colony site before they were repeatedly driven away by recreational swimmers. They
eventually abandoned the site. The bird was designated extirpated as a nesting species in 1985’s Species of Special
Concern in Pennsylvania, published by the Pennsylvania Biological Survey. The bird was upgraded to endangered in 1999, after
a pair laid eggs in a nest in the Natural Area at Presque Isle State Park.
IDENTIFYING CHARACTERISTICS: Smaller than a gull, with a long, forked tail, this mostly
gray tern has a black cap and white throat. Its legs and bill are orange-red; body length, 15 inches; wingspan, 2 ½ feet.
This tern’s rapid flight and habit of pointing its bill downward distinguish it from other gulls.
BIOLOGY-NATURAL HISTORY: Common terns, also known as "sea swallows" for their characteristic
forked tail, may arrive in the state as early as the second week of April. Their typical migration period is from the last
week of April or first week of May to the fourth week of May.
PREFERRED HABITAT: Common terns are usually seen flying over lakes, slow-moving rivers,
or occasionally marshes; or perched on beaches, sand pits, mudflats, or on structures such as buoys or piers. The birds are
drawn to areas where watery action – currents, slapping waves or, tossing shoals – churns small fish and aquatic
insects. They dive head-first after prey. Nesting habitat is restricted to sandy shorelines of large lakes. Gull Point in
Presque Isle State Park is the only suitable location for nesting.
REASON FOR BEING ENDANGERED: The common tern’s breeding population, like many other
waterbirds that nest on sandy beaches and dunes, has declined throughout the Great Lakes and Atlantic coastal regions because
of intrusive human activities at nesting sites. It is endangered in Pennsylvania because it currently at best is an infrequent
nester that may require site protection to ensure nesting success. Increased populations of egg predators (raccoons, skunks
and gulls) also threatens nesting attempts.
MANAGEMENT PROGRAMS: Since a pair of common terns was discovered nesting at Presque Isle
in 1995 and 1996, the species has been designated as endangered. Intensified surveys are needed to determine whether nesting
is occurring elsewhere. Monitoring is also needed to ensure new nests are not disturbed.
Least Bittern
CURRENT STATUS: In Pennsylvania, endangered; Migratory Bird of Management Concern in the
Northeast.
POPULATION TREND: Least bitterns (Ixobrychus Exilis) are locally uncommon breeders in the
Tinicum area in Philadelphia County; at Presque Isle State Park in Erie County; and in larger emergent wetlands in the state’s
northwestern counties. They are rare in suitable habitat elsewhere in the state. Least bitterns are declining in areas where
their largest historical populations have been found. At Tinicum, only a few pairs have been nesting in recent years. In the
late 1950s, however, as many as 27 nests were recorded there. Least bitterns were first designated as a threatened species
in 1979. In 1997, the species was downgraded to endangered.
IDENTIFYING CHARACTERISTICS: The smallest member of the heron family, the least bittern
is 11 to 14 inches in length and has a 16- to 18-inch wingspan. This primarily black and tan bird has a blackish-green cap
and back, brown neck and underparts, and a white throat. The least bittern is most readily identified in flight by conspicuous,
chestnut-colored wing patches. A rare, darker phase also exists. When disturbed, the least bittern is more likely to run than
fly, and like its relative, the American bittern, it also has the habit of freezing with its bill pointed straight up when
alarmed.
BIOLOGY-NATURAL HISTORY: The least bittern nests in wetland areas throughout the eastern
United States and along the Pacific coast. It spends the winter from our southern states south to Colombia, South America.
This species is a regular migrant through the state, but it nests regularly in our northwest and southeast corners only, and
possibly in a few other scattered locations, but not regularly or in significant numbers. The least bittern arrives in Pennsylvania
in April and builds its platform nest of reeds and grasses near open water. Four or five pale blue or green eggs are laid
in the six-inch nest in mid or late May. The young hatch in just under three weeks.
PREFERRED HABITAT: Least bitterns thrive in dense marshland environments containing cattails
and reeds, along the coast and inland, where they feed primarily on small fish, amphibians, insects and small mammals. They
frequent brushy wetlands more frequently than their larger cousin, the American bittern.
REASONS FOR BEING ENDANGERED: Nesting opportunities for this species in Pennsylvania are limited and decreasing
as the wetland habitat it needs has been extensively drained or impounded. Loss of tidal marshes along the Delaware River
has been key to the bird’s decline in the state. Its future is largely dependent upon safeguarding the state’s
remaining large marshes.
MANAGEMENT PROGRAMS: Areas where this species is known to nest should be uncompromisingly
protected. Surveys to further determine where least bitterns nest are ongoing. Marshland habitats, when possible, should be
managed to provide additional nesting habitat.
Great Egret
CURRENT STATUS: In Pennsylvania, endangered; nationally, no special protection.
POPULATION TREND: Great egrets (Ardea Alba) are the most common and largest of the four
white herons that regularly occur in Pennsylvania. They are uncommon to rare regular visitors throughout the state where suitable
habitat exists, becoming more common in late summer. In Pennsylvania, great egrets nest only on the Susquehanna River’s
Wade Island in Pennsylvania, where about 150 nests are found annually. Great egrets are seen occasionally in winter in southeastern
counties. First listed as a threatened species in 1990, the great egret was downgraded to endangered in 1999. A significant
nesting site for great egrets was lost in the late 1980s when the birds deserted the Susquehanna River’s Rookery Island
near Washington Boro. They have not returned since then.
IDENTIFYING CHARACTERISTICS: From bill to tail tip, adults are about 40 inches long. The
wingspan is 55 inches. The plumage is white, bill yellowish, and legs and feet black.
BIOLOGY-NATURAL HISTORY: The major distribution of this species is south of Pennsylvania. Fingers of a Mid-Atlantic
coastal population extend into the Delaware and Susquehanna drainages. During migration, this species drifts slowly southward.
By mid-spring, nesting has started. A nest of sticks contains three to four pale bluish-green eggs. After a 24-day incubation
period and six weeks as nestlings, young are ready to fly. Maturity may not be reached until the third year. Food consists
of frogs, minnows and other small aquatic animals.
PREFERRED HABITAT: This egret is typically found feeding in shallow rivers, streams, ponds,
lakes and marshes. Nests are found in adjacent trees or shrubby growth, preferably on islands. The birds usually nest in colonies
that may include other colonial nesting species.
REASONS FOR BEING ENDANGERED: Years ago, this species was hunted for its feathers. By 1917, some doubted
the bird could be saved from extinction. Pennsylvania’s first documented nesting record was in 1957. By 1990, birds
had established three modest colonies here. Today, the main threats faced by the great egret are habitat loss (flooding of
shallow feeding areas as a result of dams, for example), water pollution, and disturbance of nesting colonies.
MANAGEMENT PROGRAMS: Colonial nesting birds are vulnerable to disturbance and direct persecution.
All known nesting colonies should be closed to public intrusion and safeguarded from developmental pressures.
Short-Eared Owl
Current Status: In Pennsylvania, endangered; Migratory Bird of Management Concern in the
Northeast.
POPULATION TREND: Short-eared owls (Asio Flammeus) may be found regularly during winter
throughout the state, but numbers vary from year to year. They have recently been found nesting on reclaimed strip-mines in
western Pennsylvania, from Clarion and Venango counties south to Allegheny County. But nest sites are rarely documented to
be active for more than a few years in succession. The bird was designated endangered in 1985’s Species of Special Concern
in Pennsylvania, published by the Pennsylvania Biological Survey. Its status hasn’t changed since then.
IDENTIFYING CHARACTERISTICS: The short-eared owl received its name from its lack of "ear"
tufts. It’s about the size of a crow, 13 to 17 inches high, and has a 38- to 44-inch wingspan. Color is variable, from
light to dark brown. The dark patches on the undersides of its wings, and large buff-colored patches on the upper sides are
very distinctive. There are also dark patches around the eyes.
BIOLOGY-NATURAL HISTORY: Short-eared owls are birds of open country. They may be found in Pennsylvania throughout
the year. They nest on the ground, sometimes in colonial groups. The nest is a slight depression, sparsely lined with grass
and feathers, often at the base of a clump of weeds or grasses. A normal clutch consists of four to seven white eggs. Young
hatch about three weeks after egg laying, and are able to fly in about a month. Unlike most other owls, the short-eared is
active at dusk, dawn and – at times – even in midday; therefore, they are seen more often than other owl species.
PREFERRED HABITAT: Short-ears inhabit reclaimed strip mines, open, uncut grassy fields,
large meadows, airports and occasionally, marshland. In agricultural areas they are attracted to Conservation Reserve Program
fields and other areas with tall winter grass. Short-eared owls are more likely to be encountered here in the winter when
several may be seen together, hovering or flying low and in circles over agricultural fields in search of their main prey,
meadow mice.
REASONS FOR BEING ENDANGERED: Suitable nesting habitat for the short-eared owl is extremely limited in Pennsylvania,
and intensive agricultural practices make many potential habitats unsuitable.
MANAGEMENT PROGRAMS: In Pennsylvania, most open lands are farmlands and, therefore, subject
to repeated disturbance. Accordingly, the welfare of grassland nesting birds is threatened. This may be why the only known
nests of short-eared owls were discovered in extensive and low-disturbance open lands, such as a strip mine reclaimed to grass.
Future management based on the needs for safe nesting habitat for all grassland nesters, should include the creation of large,
herbaceous reserves suitable for all grassland nesters. Such reserves might include airports, reclaimed strip mines and large
pastures. Primary management of these areas must assure a disturbance-free nesting season.
American Bittern
CURRENT STATUS: In Pennsylvania, endangered; Migratory bird of special concern in the Northeast.
POPULATION TREND: American bitterns (Botaurus Lentiginosus) are uncommon to rare regular
migrants in most of Pennsylvania. In Crawford County, however, they are regular breeding residents in scattered large wetlands,
especially Geneva Marsh on State Game Lands 213. Nesting activity has been confirmed or suspected in 17 counties in the twentieth
century. The American bittern has suffered greatly from the loss of wetland habitat, especially in southeastern Pennsylvania,
where many marshes once used by breeding bitterns have been filled for development or choked by sedimentation. This species
was listed as a threatened species from 1979 until 1997, when it was downgraded to endangered.
IDENTIFYING CHARACTERISTICS: This large, cryptically-colored heron is most often seen when
flushed from marshes. It's most easily identified by its large size – up to 34 inches tall and with a 50-inch wingspan
– and its streaked, brown plumage. At rest, its black moustache-like cheek markings are diagnostic. In flight, conspicuous
black outer wings are characteristic. The secretive American bittern may be best known for its habit, when it feels threatened,
of standing upright with its bill pointing upward. At times it even sways from side to side, moving like the tall reeds and
grasses surrounding it. In this pose the bird blends in with its surroundings and easily goes unnoticed.
BIOLOGY-NATURAL HISTORY: American bitterns nest in marshes across the northern United States
and southern Canada. They winter across the southern United States, through Mexico and into Central America. They nest singly,
not in colonies like many other herons. This bird may be found year-round in Pennsylvania, but bitterns are most often seen
here during spring and fall migrations. A few nest in scattered marshes across Pennsylvania, particularly, in the Pymatuning
region. American bitterns build platform nests of reeds and grasses near the water, and normally lay a clutch of three to
seven buff or olive-brown eggs. Young hatch in 24 to 28 days and leave the nest after another two weeks. They are often seen
stalking along shorelines and marshes where they prey on frogs, fish, snakes, crayfish, insects and other aquatic organisms.
PREFERRED HABITAT: American bitterns require large wetland habitats. They are most likely
found in marshes and wetland borders along lakes, ponds, rivers and streams. American bitterns seem to prefer to breed in
extensive freshwater marshes, especially those with dense stands of cattails and thick patches of bulrushes, grasses and sedges
and pockets of open water.
REASON FOR BEING ENDANGERED: The American bittern is endangered because of its dependency
on specialized marshes; wetlands have declined by more than 50 percent in Pennsylvania over the past two centuries. Marshes
remain at risk from sedimentation and, to a lesser degree, encroachment. Habitat is key to any population augmentation of
this species.
MANAGEMENT PROGRAMS: Areas in Pennsylvania where American bitterns regularly nest have been
identified and are being protected when possible from development. Protection efforts include easements, land acquisition
and public education. Game Commission biologists and others who routinely perform bird survey/census work will continue to
monitor the species for changes in distribution and nesting occurrences.
Species Profile
Current Status: In Pennsylvania, endangered; nationally, removed from list August
1999.
Population Trend: Pennsylvania’s peregrine falcon population has been slowly
building since the early 1990s. The increase is a direct result of peregrine hacking/reintroduction efforts in Pennsylvania
and other states. Hacking is placing young birds in a rooftop or elevated enclosure for several weeks until they’re
ready to fledge, or fly from the nest. At that time the enclosure is opened, and the birds come and go as they please. Eventually
they leave, but some will return to hacking areas to nest in subsequent years. Pennsylvania’s nesting population numbers
about a dozen pairs. All recent nests have been on buildings and bridges in urban settings. Peregrines remain an endangered
species in the commonwealth. Nationally, however, peregrines were recently removed from the federal Endangered Species List.
National delisting was a direct result of the bird’s dramatic recovery across the country.
Identifying Characteristics: A 15- to 22-inch falcon, adults have dark-bluish gray upperparts and wings.
Underparts are whitish to buffy colored, broken by horizontal bars. Birds up to two years old are marked with dark brown,
rather than gray, on their wings and back. The head has a nearly black "helmet." Like all falcons, the peregrine has long
pointed wings and rapid, steady wing beats in flight.
Biology-Natural History: The peregrine falcon was listed as endangered in 1984. Records
indicate the bird did not nest in Pennsylvania from about 1959 to 1987. The native breeding population of peregrines in the
eastern United States was wiped out by the mid 1960s, primarily due to effects of DDT. It was estimated to number about 350
nesting pairs in the early 1900s. The true eastern peregrine falcon is extinct. A new population was established from captive-bred
birds reintroduced by the Peregrine Fund. The largest concentration of nesting peregrines in the East is currently along the
Hudson River where pairs nest on bridges and buildings in the metropolitan New York City area, and on towers and buildings
along the New Jersey coast. The East’s reestablished peregrine population is believed to be self-sustaining. Pennsylvania’s
largest nesting concentrations are on the bridges spanning the Schuylkill and Delaware rivers in Buck County and Philadelphia.
The peregrine nests in many parts of the world. They feed primarily on other birds, typically by striking them in flight.
A clutch of four eggs is normally laid, and the birds may remain in Pennsylvania the year round. Click here to observe activities
at a peregrine falcon nest on the Rachel Carson Building, which houses the state departments of Environmental Protection and
Conservation and Natural Resources, in downtown Harrisburg.
Preferred Habitat: Historically, peregrine falcons nested on high cliffs overlooking river
systems. Records indicate peregrines once nested at 44 sites in at least 21 counties. Today, peregrines are more apt to be
found nesting on high bridges and tall buildings within cities. As a result, they frequently feed on pigeons and other urban
birds. After an absence of nearly three decades, the return of breeding peregrines to Pennsylvania was first documented on
bridges spanning the Delaware and Schuylkill rivers in the Philadelphia area. In 1990, a pair began nesting in Pittsburgh.
Reasons For Being Endangered: By 1961, peregrines were no longer found in Pennsylvania. Their
decline and extirpation has been attributed to egg collecting and shooting, but chiefly to pesticides – particularly
DDT (See osprey entry for addition information on how DDT affected some birds).
Management Practices: State management plans include annual surveys for new nest sites; protection
of known nest sites; reduction of hazards at nest sites to increase survival of young peregrines; and promotion of public
support. Hacking/reintroduction's occurred in Harrisburg, Reading and Williamsport during the 1990s. The aim of management
efforts at this time is to restore peregrines at suitable historic cliff sites along major rivers and to enhance nesting success
on buildings and bridges. Emphasis on future federal recovery efforts will be on habitat protection. Protecting existing nest
sites and potential habitat to accommodate increasing peregrine falcon population levels is critically important.
Yellow-Crowned Night Heron
CURRENT STATUS: In Pennsylvania, endangered; nationally, no special protection.
POPULATION TREND: Yellow-crowned night herons (Nyctanassa violacea) are rare, regular visitors
or residents in the Piedmont Region of southeastern Pennsylvania, where they breed locally. In the coastal plain area along
the Delaware River near Philadelphia, they are rare, irregular visitors. They are casual to accidental visitors elsewhere
in the state. Most summer sightings are reported along the tributaries of the Susquehanna River in Cumberland, Lancaster and
York counties. They nest singly and in loose colonies regularly along Conodoquinet Creek near its confluence with the Susquehanna.
Nests are also found along Conestoga and Little Conestoga creeks in Lancaster County. Surveys in the 1990s counted not more
than eight to 12 nests in any year in the state. Yellow-crowned night heron were first listed as threatened species in 1990
because of their limited population and restricted range. They were downgraded to endangered in 1999 because of their small
population.
IDENTIFYING CHARACTERISTICS: Adults are 22 to 28 inches in length, from bill tip to tail
tip, gray with black head and a whitish cheek patch and crown. Eyes are red and legs yellowish. Their name identifies a distinguishing
characteristic – the yellowish crown, or top of the head. Immature birds are brown, finely spotted and streaked with
white buff.
BIOLOGY-NATURAL HISTORY: Pennsylvania lies at the northern fringe of this species’
breeding range, which is mainly in the south-central United States. It nests singly or in small groups in the lower reaches
of the Susquehanna River. A typical clutch contains three or four eggs. Nesting starts as early as April. By mid-summer most
young have fledged. Crayfish are a major part of this bird’s diet.
PREFERRED HABITAT: Feeds mainly along small shallow streams. Nests in brush or trees, usually
sycamores, found on islands or along streams. Most nests found in recent years are along the Susquehanna River and its tributaries
in Lancaster County. Birds seem tolerant of human activities. They are known to nest within 100 yards of houses and roads.
REASONS FOR BEING ENDANGERED: As a breeding bird, the combination of rarity and tendency
to nest in small groups makes this species particularly vulnerable to local habitat disturbance or loss. The largest nesting
colony known in Pennsylvania, representing more than half the state’s known breeding population, was on a small Susquehanna
River island, located offshore of the Governor’s Residence. It subsequently moved to the mouth of the Conodoquinet,
but disturbance there appears to have dispersed the colony. The integrity of this site and nearby shallow-water feeding areas
are threatened by a proposed dam. Degradation of water quality, along with loss of the primary food source – crayfish
– is an ever-present threat.
MANAGEMENT PRACTICES: Known nest sites for this species are monitored and potential new
sites need to be surveyed. Whenever possible, nesting habitats need to be protected.
Delmarva Fox Squirrel
CURRENT STATUS: Pennsylvania, endangered; nationally, endangered
POPULATION TREND: Population trends for the Delmarva fox squirrel (Sciurus Niger Cinereus)
in Pennsylvania are unknown. It has generally been accepted that this large subspecies of fox squirrel has disappeared from
many of its historic sites because of the pressures caused by urban sprawl. But people living in the area where this squirrel
was re-introduced in the 1980s have reported seeing large fox squirrels in the types of habitat fox squirrels prefer. If any
populations exist in Pennsylvania, they are very small and in extreme jeopardy of disappearing altogether. Nationally, this
species is barely holding its own along the eastern shore of the Chesapeake Bay. In some areas, though, populations remain
stable.
IDENTIFYING CHARACTERISTICS: A very large squirrel, averaging up to 2½ to 3 pounds, it resembles
the much more common gray squirrel. Buffy-gray to steel gray along the back, the hairs are often black tipped. The feet and
toes are cream- to buff-colored as are the nose and ears. The long hairs of the tail are generally black with white tips.
While body color may serve to distinguish this species, its large size is the most significant characteristic.
BIOLOGY-NATURAL HISTORY:The Delmarva fox squirrel ranged historically from the extreme southeasten portion
of Pennsylvania into Delaware, Maryland and Virginia along what is referred to the Delmarva Peninsula. It has become restricted
recently in Maryland to several counties and the Chincoteaque National Wildlife Refuge. While its preferred foods are characteristic
of other squirrels, the Delmarva has been known to eat red maple buds and seeds in the spring during periods of low food supplies.
Food is thought to be a deciding factor determining the size of a litter and the number of litters per year.
PREFERRED HABITAT:The Delmarva fox squirrel spends more time on the forest floor than do
gray squirrels. Its preferred habitat is generally described as forest with thick canopy closure accompanied by an open and
sparsely vegetated understory. Some researchers describe Delmarva habitat as "park-like" forest.
MANAGEMENT PRACTICES:A program in the 1980s to re-introduce the Delmarva fox squirrel to portions of Chester
County was unsuccessful, based on a lack of subsequent squirrel sightings. Surveys of boxes erected to provide nest sites
for the Delmarva remain unused except for those used by southern flying squirrels and gray squirrels. Until an inventory of
possible habitat is carried out to determine whether existing habitat can support the Delmarva fox squirrel, any new re-introductions
of this species have been put on hold.
