Peale's Falcon
Encyclopedia
Peale's Falcon, Falco peregrinus pealei, is a subspecies
of the Peregrine Falcon
. This race was first identified by the ornithologist
Robert Ridgway in 1873, named in honor of Titian Ramsay Peale. These birds are the largest subspecies of Peregrines (on average) anywhere in the world. Measurements for male F. p. pealei are as follows: length 16.3 in. (41.4 cm), wingspan 36.2 in. (92.1 cm), wing chord 12.60-13.58 in. (320–345 mm). For females: length 19.1 in. (48 cm), wingspan 43.6 in. (110.8 cm), wing chord 14.29-15.39 in. (363–391 mm)
Weight range for male F. p. pealei are 28.57-37.32 oz. (810-1,058 g), averaging 33.65 oz. (954 g); females range 43.88-56.33 oz. (1,244-1,597 g), averaging 49.31 oz. (1,398 g).
The adults are generally identified by the presence of heavy horizontal barring across their abdomen, large "tear-drop" shaped markings on their breast (more pronounced in the females) extending up into the auriculars
, a white, smokey-white, or grayish background color on the breast (as opposed to the salmon
to orangish background color on most other subspecies), very broad malar
stripe to a full dark cap, and wider, stronger mandibles
than is commonly seen in the species as a whole.
Immature birds are overall very dark, having little to no buff colored edging to the feathers of the mantle. Nearly completely dark heads and very heavily streaked ventral markings. Retrices are usually unbarred. Feet and cere color varies from light blue to light yellow.
and possibly the northern Kurile Islands, no evidence has been provided to support these locations. From the Commander Islands eastward they are found throughout the Aleutian Islands to the Sanak Islands
, Cherni Island
, Deer Island
, the Pavlof Islands
, and the Shumagin Islands
. This area constitutes the western sub-population of F. p. pealei and is an estimated 375-580 breeding pairs strong in Alaskan territory and 20-25 pairs in Russian territory. This group has a very uniformely and densely distributed population, with roughly 5–8 miles of coastline between each eyrie on average. This group also has a tendency to be more uniform in morphology.
The Alexander Archipelago
, Queen Charlotte Islands
, portions of the British Columbia
coast, the outer coast of Vancouver Island
, and the Olympic Peninsula
make up the eastern sub-population of F. p. pealei. The highest density of Peregrines anywhere in the world was recorded on Langara Island
in the middle 1950's. Ten nests being occupied in a single small bay of only 7.5 mi (12 km) of coastline, and a total of 21 nests on the whole island. Unfortunately this astounding concentration of Peregrine falcons was intimately linked to the very robust local seabird population that has declined since the 1950s due to unknown factors. Possible culprits for the decline include introduced non-native predators of seabirds such as rat
s and raccoon
s, coupled with possible changes brought on by human activities in the oceanic food chain on which the seabird colonies depend. The Peregrine population of Langara Island is now believed to be about 25% of what it once was. The current population of the eastern sub-group of F. p. pealei is about 20 breeding pairs in Washington, about 100 pairs in British Columbia, and about another 100 pairs in the Alexander Archipelago.
Along the south side of the Alaska Peninsula
, the Kodiak Islands, portions of Cook Inlet
, the Kenai Peninsula
, Prince William Sound
, and eastward to Glacier Bay
constitutes the central sub-population of F. p. pealei. This area is marked by a decidedly lower population density than either the eastern or western populations. This fact and the slightly different morphology of this sub-group has caused some confusion amongst researchers as to the validity of F. p. pealei existing within this range.
Specifically within this range, the Peale's Falcon can be found on rough, rocky seashores, sea cliffs, seastacks
, islands, islet
s, and beaches.
. In fact the subspecies is well known to nest very near seabird colonies for the convenience of close hunting grounds. However this is not necessary for a successful eyrie. In a study on Amchitka
Island from 1968-1973, it was found that an average of 18.6 eyries on the island (over the course of the study) were in no close proximity to seabird colonies as no sizable colonies existed on the island. Instead, these large, robust birds fly out to sea to hunt up to 50 miles from land, rather than inland toward the interior. Which is quite an impressive physical feat as they must either eat their prey while flying or carry the prey back to land to perch and then consume it, as Peregrines are not known to be able to rest and stay afloat on water as seabirds do. Preferred species on Amchitka consisted of: Crested Auklet (Aethia cristatella)
, 26.48% of the diet's biomass; Ancient Murrelet (Synthliboramphus antiquus)
, 17.18% of the biomass; and Alcids as a group provided 65.52% of the biomass.
Other important prey species that this specialized population of Peregrines are fond of are Fork-tailed Storm-Petrel
s, Leach's Storm-Petrel
s, and Black-legged Kittiwake
s.
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
of the Peregrine Falcon
Peregrine Falcon
The Peregrine Falcon , also known as the Peregrine, and historically as the Duck Hawk in North America, is a widespread bird of prey in the family Falconidae. A large, crow-sized falcon, it has a blue-gray back, barred white underparts, and a black head and "moustache"...
. This race was first identified by the ornithologist
Ornithology
Ornithology is a branch of zoology that concerns the study of birds. Several aspects of ornithology differ from related disciplines, due partly to the high visibility and the aesthetic appeal of birds...
Robert Ridgway in 1873, named in honor of Titian Ramsay Peale. These birds are the largest subspecies of Peregrines (on average) anywhere in the world. Measurements for male F. p. pealei are as follows: length 16.3 in. (41.4 cm), wingspan 36.2 in. (92.1 cm), wing chord 12.60-13.58 in. (320–345 mm). For females: length 19.1 in. (48 cm), wingspan 43.6 in. (110.8 cm), wing chord 14.29-15.39 in. (363–391 mm)
Weight range for male F. p. pealei are 28.57-37.32 oz. (810-1,058 g), averaging 33.65 oz. (954 g); females range 43.88-56.33 oz. (1,244-1,597 g), averaging 49.31 oz. (1,398 g).
The adults are generally identified by the presence of heavy horizontal barring across their abdomen, large "tear-drop" shaped markings on their breast (more pronounced in the females) extending up into the auriculars
Ear
The ear is the organ that detects sound. It not only receives sound, but also aids in balance and body position. The ear is part of the auditory system....
, a white, smokey-white, or grayish background color on the breast (as opposed to the salmon
Salmon (color)
Salmon a range of pale pinkish-orange to light pink colors, named after the color of salmon flesh.The web color salmon is displayed at right.The first recorded use of salmon as a color name in English was in 1776...
to orangish background color on most other subspecies), very broad malar
Malar
Malar may refer to:* Malar, Iran, a city in Iran* Malar, Pakistan, a town in Pakistan* Malar , a deity in the Forgotten Realms campaign setting of Dungeons & Dragons* Relating to the cheek...
stripe to a full dark cap, and wider, stronger mandibles
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
than is commonly seen in the species as a whole.
Immature birds are overall very dark, having little to no buff colored edging to the feathers of the mantle. Nearly completely dark heads and very heavily streaked ventral markings. Retrices are usually unbarred. Feet and cere color varies from light blue to light yellow.
Distribution, Habitat, and Population Status
The breeding range of F. p. pealei is a rather linear one being entirely coastal in orientation. Starting in the western part of the range, the Commander Islands are generally thought to be the extent to which they exist in Russia. Although they are speculatively referenced as nesting on the Kamchatka PeninsulaKamchatka Peninsula
The Kamchatka Peninsula is a peninsula in the Russian Far East, with an area of . It lies between the Pacific Ocean to the east and the Sea of Okhotsk to the west...
and possibly the northern Kurile Islands, no evidence has been provided to support these locations. From the Commander Islands eastward they are found throughout the Aleutian Islands to the Sanak Islands
Sanak Islands
The Sanak Islands are a group of islands in the Gulf of Alaska. They are part of Aleutians East Borough in the state of Alaska, USA. Caton Island and Sanak Island are the largest islands in the group which consists of small islets which are all clustered around Sanak Island.Sanak Island is near the...
, Cherni Island
Cherni Island
Cherni Island is an island in Alaska, USA that lies 12 miles south of Deer Island, about half way between it and the Sanak Islands. All of the preceding islands lie off the south coast of the western part of the Alaska Peninsula, in the Aleutians East Borough....
, Deer Island
Deer Island (Alaska)
Deer Island is an island located at the mouth of Cold Bay on the south side of the Alaska Peninsula in the state of Alaska, USA. It lies about five miles directly south of the mainland city of King Cove, across Deer Passage. The Sanak Islands lie to its south, and the Pavlof Islands to its northeast...
, the Pavlof Islands
Pavlof Islands
The Pavlof Islands are a group of seven islands that lie south of Pavlof Bay on the Alaska Peninsula of Alaska, USA. They are part of the Aleutians East Borough of Alaska...
, and the Shumagin Islands
Shumagin Islands
The Shumagin Islands are a group of 20 islands in the Aleutians East Borough south of the mainland of Alaska, USA, at54°54'–55°20' North 159°15'–160°45' West. The largest islands are Unga Island, Popof Island, Korovin Island, and Nagai Island. Other islands include Andronica, Big Koniuji, Little...
. This area constitutes the western sub-population of F. p. pealei and is an estimated 375-580 breeding pairs strong in Alaskan territory and 20-25 pairs in Russian territory. This group has a very uniformely and densely distributed population, with roughly 5–8 miles of coastline between each eyrie on average. This group also has a tendency to be more uniform in morphology.
The Alexander Archipelago
Alexander Archipelago
The Alexander Archipelago is a long archipelago, or group of islands, of North America off the southeastern coast of Alaska. It contains about 1,100 islands, which are the tops of the submerged coastal mountains that rise steeply from the Pacific Ocean. Deep channels and fjords separate the...
, Queen Charlotte Islands
Queen Charlotte Islands
Haida Gwaii , formerly the Queen Charlotte Islands, is an archipelago on the North Coast of British Columbia, Canada. Haida Gwaii consists of two main islands: Graham Island in the north, and Moresby Island in the south, along with approximately 150 smaller islands with a total landmass of...
, portions of the British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
coast, the outer coast of Vancouver Island
Vancouver Island
Vancouver Island is a large island in British Columbia, Canada. It is one of several North American locations named after George Vancouver, the British Royal Navy officer who explored the Pacific Northwest coast of North America between 1791 and 1794...
, and the Olympic Peninsula
Olympic Peninsula
The Olympic Peninsula is the large arm of land in western Washington state of the USA, that lies across Puget Sound from Seattle. It is bounded on the west by the Pacific Ocean, the north by the Strait of Juan de Fuca, and the east by Puget Sound. Cape Alava, the westernmost point in the contiguous...
make up the eastern sub-population of F. p. pealei. The highest density of Peregrines anywhere in the world was recorded on Langara Island
Langara Island
Langara Island is the northernmost Island of the Queen Charlotte Islands in British Columbia, Canada. The island is approximately in size. It is located approximately south of Alaska.-History:...
in the middle 1950's. Ten nests being occupied in a single small bay of only 7.5 mi (12 km) of coastline, and a total of 21 nests on the whole island. Unfortunately this astounding concentration of Peregrine falcons was intimately linked to the very robust local seabird population that has declined since the 1950s due to unknown factors. Possible culprits for the decline include introduced non-native predators of seabirds such as rat
Brown Rat
The brown rat, common rat, sewer rat, Hanover rat, Norway rat, Brown Norway rat, Norwegian rat, or wharf rat is one of the best known and most common rats....
s and raccoon
Raccoon
Procyon is a genus of nocturnal mammals, comprising three species commonly known as raccoons, in the family Procyonidae. The most familiar species, the common raccoon , is often known simply as "the" raccoon, as the two other raccoon species in the genus are native only to the tropics and are...
s, coupled with possible changes brought on by human activities in the oceanic food chain on which the seabird colonies depend. The Peregrine population of Langara Island is now believed to be about 25% of what it once was. The current population of the eastern sub-group of F. p. pealei is about 20 breeding pairs in Washington, about 100 pairs in British Columbia, and about another 100 pairs in the Alexander Archipelago.
Along the south side of the Alaska Peninsula
Alaska Peninsula
The Alaska Peninsula is a peninsula extending about to the southwest from the mainland of Alaska and ending in the Aleutian Islands. The peninsula separates the Pacific Ocean from Bristol Bay, an arm of the Bering Sea....
, the Kodiak Islands, portions of Cook Inlet
Cook Inlet
Cook Inlet stretches from the Gulf of Alaska to Anchorage in south-central Alaska. Cook Inlet branches into the Knik Arm and Turnagain Arm at its northern end, almost surrounding Anchorage....
, the Kenai Peninsula
Kenai Peninsula
The Kenai Peninsula is a large peninsula jutting from the southern coast of Alaska in the United States. The name Kenai is probably derived from Kenayskaya, the Russian name for Cook Inlet, which borders the peninsula to the west.-Geography:...
, Prince William Sound
Prince William Sound
Prince William Sound is a sound off the Gulf of Alaska on the south coast of the U.S. state of Alaska. It is located on the east side of the Kenai Peninsula. Its largest port is Valdez, at the southern terminus of the Trans-Alaska Pipeline System...
, and eastward to Glacier Bay
Glacier Bay
Glacier Bay Basin in southeastern Alaska, United States, encompasses the Glacier Bay and surrounding mountains and glaciers, which was first proclaimed a U.S. National Monument on February 25, 1925 and which was later, on Dec...
constitutes the central sub-population of F. p. pealei. This area is marked by a decidedly lower population density than either the eastern or western populations. This fact and the slightly different morphology of this sub-group has caused some confusion amongst researchers as to the validity of F. p. pealei existing within this range.
Specifically within this range, the Peale's Falcon can be found on rough, rocky seashores, sea cliffs, seastacks
Stack (geology)
A stack is a geological landform consisting of a steep and often vertical column or columns of rock in the sea near a coast, isolated by erosion. Stacks are formed through processes of coastal geomorphology, which are entirely natural. Time, wind and water are the only factors involved in the...
, islands, islet
Islet
An islet is a very small island.- Types :As suggested by its origin as islette, an Old French diminutive of "isle", use of the term implies small size, but little attention is given to drawing an upper limit on its applicability....
s, and beaches.
Hunting and Food Habits
The Peale's falcon is known to concentrate its hunting efforts on AlcidsAuk
An auk is a bird of the family Alcidae in the order Charadriiformes. Auks are superficially similar to penguins due to their black-and-white colours, their upright posture and some of their habits...
. In fact the subspecies is well known to nest very near seabird colonies for the convenience of close hunting grounds. However this is not necessary for a successful eyrie. In a study on Amchitka
Amchitka
Amchitka is a volcanic, tectonically unstable island in the Rat Islands group of the Aleutian Islands in southwest Alaska. It is part of the Alaska Maritime National Wildlife Refuge. The island is about long, and from wide...
Island from 1968-1973, it was found that an average of 18.6 eyries on the island (over the course of the study) were in no close proximity to seabird colonies as no sizable colonies existed on the island. Instead, these large, robust birds fly out to sea to hunt up to 50 miles from land, rather than inland toward the interior. Which is quite an impressive physical feat as they must either eat their prey while flying or carry the prey back to land to perch and then consume it, as Peregrines are not known to be able to rest and stay afloat on water as seabirds do. Preferred species on Amchitka consisted of: Crested Auklet (Aethia cristatella)
Crested Auklet
The Crested Auklet is a small seabird of the family Alcidae which nests in huge colonies in the Bering Sea and Sea of Okhotsk. They often breed in mixed-species colonies with Least Auklets, their smaller congener.The Crested Auklet can measure in length, in wingspan and weigh...
, 26.48% of the diet's biomass; Ancient Murrelet (Synthliboramphus antiquus)
Ancient Murrelet
The Ancient Murrelet, Synthliboramphus antiquus, is a bird in the auk family. It breeds from the Yellow Sea , through the Russian Pacific coast and the Aleutian Islands to the Haida Gwaii archipelago of British Columbia, where about half of the world population breeds.These birds breed in colonies,...
, 17.18% of the biomass; and Alcids as a group provided 65.52% of the biomass.
Other important prey species that this specialized population of Peregrines are fond of are Fork-tailed Storm-Petrel
Fork-tailed Storm-petrel
The Fork-tailed Storm Petrel is a small seabird of the storm-petrel family Hydrobatidae. It is 20–23 cm in length, with a wingspan of 46 cm...
s, Leach's Storm-Petrel
Leach's Storm-petrel
The Leach's Storm Petrel or Leach's Petrel is a small seabird of the tubenose family. It is named after the British zoologist William Elford Leach....
s, and Black-legged Kittiwake
Black-legged Kittiwake
The Black-legged Kittiwake is a seabird species in the gull family Laridae.This species was first described by Linnaeus in his Systema naturae in 1758 as Larus tridactylus....
s.