THE OSPREY

The osprey or more specifically the western osprey (Pandion haliaetus) — also called sea hawk, river hawk, and fish hawk — is a diurnal, fish-eating bird of prey with a cosmopolitan range. It is a large raptor, reaching more than 60 cm (24 in) in length and 180 cm (71 in) across the wings. It is brown on the upperparts and predominantly greyish on the head and underparts.
The osprey tolerates a wide variety of habitats, nesting in any location near a body of water providing an adequate food supply. It is found on all continents except Antarctica, although in South America it occurs only as a non-breeding migrant.
As its other common names suggest, the osprey's diet consists almost exclusively of fish. It possesses specialised physical characteristics and exhibits unique behaviour to assist in hunting and catching prey. As a result of these unique characteristics, it has been given its own taxonomic genus, Pandion and family, Pandionidae. Three subspecies are usually recognized, one of the former subspecies cristatus has recently been given full species status and is referred to as the eastern osprey. Despite its propensity to nest near water, the osprey is not classed as a sea eagle.

 

Taxonomy and systematics

The osprey was one of the many species described by Carl Linnaeus in his 18th-century work, Systema Naturae, and named as Falco haliaeetus.^[2] The genus, Pandion, is the sole member of the family Pandionidae, and used to contain only one species, the osprey (P. haliaetus). The genus Pandion was described by the French zoologist Marie Jules César Savigny in 1809.^[3][4]
Most taxonomic authorities consider the species cosmopolitan and conspecific. A few authorities split the osprey into two species, the western osprey and the eastern osprey.
The osprey differs in several respects from other diurnal birds of prey. Its toes are of equal length, its tarsi are reticulate, and its talons are rounded, rather than grooved. The osprey and owls are the only raptors whose outer toe is reversible, allowing them to grasp their prey with two toes in front and two behind. This is particularly helpful when they grab slippery fish.^[5] It has always presented something of a riddle to taxonomists, but here it is treated as the sole living member of the family Pandionidae, and the family listed in its traditional place as part of the order Falconiformes.
Other schemes place it alongside the hawks and eagles in the family Accipitridae—which itself can be regarded as making up the bulk of the order Accipitriformes or else be lumped with the Falconidae into Falconiformes. The Sibley-Ahlquist taxonomy has placed it together with the other diurnal raptors in a greatly enlarged Ciconiiformes, but this results in an unnatural paraphyletic classification.^[6]

Classification

American subspecies

Australasian subspecies is the most distinctive

Californian bird with scraps of fish on its beak

The osprey is unusual in that it is a single living species that occurs nearly worldwide. Even the few subspecies are not unequivocally separable. There are four generally recognised subspecies, although differences are small, and ITIS lists only the first two.^[3]

• P. h. haliaetus – (Linnaeus, 1758): Palearctic.^[7]
• P. h. carolinensis – (Gmelin, 1788): North America. This form is larger, darker bodied and has a paler breast than nominate haliaetus.^[7]
• P. h. ridgwayi – Maynard, 1887: Caribbean islands. This form has a very pale head and breast compared with nominate haliaetus, with only a weak eye mask.^[7] It is non-migratory. Its scientific name commemorates American ornithologist Robert Ridgway.^[8]
• P. (h.) cristatus – (Vieillot, 1816): coastline and some large rivers of Australia and Tasmania. The smallest and most distinctive subspecies, also non-migratory.^[7] (most taxonomists continue to consider this a subspecies. A few authorities have given it full species status^[9] as the eastern osprey.^[10]

Fossil record

To date there have been two extinct species named from the fossil record.^[11] Pandion homalopteron was named by Stuart L. Warter in 1976 from fossils of Middle Miocene, Barstovian age, found in marine deposits in the southern part of California. The second named species Pandion lovensis, was described in 1985 by Jonathan J. Becker from fossils found in Florida and dating to the latest Clarendonian and possibly representing a separate lineage from that of P. homalopteron and P. haliaetus. A number of claw fossils have been recovered from Pliocene and Pleistocene sediments in Florida and South Carolina.
The oldest recognized family Pandionidae fossils have been recovered from the Oligocene age Jebel Qatrani Formation, of Faiyum, Egypt. However they are not complete enough to assign to a specific genus.^[12] Another Pandionidae claw fossil was recovered from Early Oligocene deposits in the Mainz basin, Germany, and was described in 2006 by Gerald Mayr.^[13]

Etymology

The genus name Pandion derives from the mythical Greek king of Athens and grandfather of Theseus, Pandion II. Although Pandion II was not used to name a bird of prey, Nisus, a king of Megara, was used for the genus.^[14] The species name haliaetus comes from Ancient Greek haliaietos ἁλιάετος^[15] from hali- ἁλι-, "sea-" and aetos άετος, "eagle".^[14]
The origins of osprey are obscure;^[16] the word itself was first recorded around 1460, derived via the Anglo-French ospriet and the Medieval Latin avis prede "bird of prey," from the Latin avis praedæ though the Oxford English Dictionary notes a connection with the Latin ossifraga or "bone breaker" of Pliny the Elder.^[17][18] However, this term referred to the Lammergeier.^[19]

Description

	Pandion haliaetus Menu 0:00
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The osprey is 0.9–2.1 kg (2.0–4.6 lb) in weight and 50–66 cm (20–26 in) in length with a 127–180 cm (50–71 in) wingspan. It is, thus, of similar size to the largest members of the Buteo or Falco genera. The subspecies are fairly close in size, with the nominate subspecies averaging 1.53 kg (3.4 lb), P. h. carolinensis averaging 1.7 kg (3.7 lb) and P. h. cristatus averaging 1.25 kg (2.8 lb). The wing chord measures 38 to 52 cm (15 to 20 in), the tail measures 16.5 to 24 cm (6.5 to 9.4 in) and the tarsus is 5.2–6.6 cm (2.0–2.6 in).^[20][21]
The upperparts are a deep, glossy brown, while the breast is white and sometimes streaked with brown, and the underparts are pure white. The head is white with a dark mask across the eyes, reaching to the sides of the neck.^[22] The irises of the eyes are golden to brown, and the transparent nictitating membrane is pale blue. The bill is black, with a blue cere, and the feet are white with black talons.^[5] A short tail and long, narrow wings with four long, finger-like feathers, and a shorter fifth, give it a very distinctive appearance.^[23]

In flight, over Lake Wylie, South Carolina

The sexes appear fairly similar, but the adult male can be distinguished from the female by its slimmer body and narrower wings. The breast band of the male is also weaker than that of the female, or is non-existent, and the underwing coverts of the male are more uniformly pale. It is straightforward to determine the sex in a breeding pair, but harder with individual birds.^[23]
The juvenile osprey may be identified by buff fringes to the plumage of the upperparts, a buff tone to the underparts, and streaked feathers on the head. During spring, barring on the underwings and flight feathers is a better indicator of a young bird, due to wear on the upperparts.^[22]
In flight, the osprey has arched wings and drooping "hands", giving it a gull-like appearance. The call is a series of sharp whistles, described as cheep, cheep or yewk, yewk. If disturbed by activity near the nest, the call is a frenzied cheereek!^[24]
  Osprey call (help·info)

Distribution and habitat

See also: Ospreys in Britain

The osprey is the second most widely distributed raptor species, after the peregrine falcon. It has a worldwide distribution and is found in temperate and tropical regions of all continents except Antarctica. In North America it breeds from Alaska and Newfoundland south to the Gulf Coast and Florida, wintering further south from the southern United States through to Argentina.^[25] It is found in summer throughout Europe north into Ireland, Scandinavia, Finland and Scotland, England, and Wales though not Iceland, and winters in North Africa.^[26] In Australia it is mainly sedentary and found patchily around the coastline, though it is a non-breeding visitor to eastern Victoria and Tasmania.^[27]
There is a 1,000 km (620 mi) gap, corresponding with the coast of the Nullarbor Plain, between its westernmost breeding site in South Australia and the nearest breeding sites to the west in Western Australia.^[28] In the islands of the Pacific it is found in the Bismarck Islands, Solomon Islands and New Caledonia, and fossil remains of adults and juveniles have been found in Tonga, where it probably was wiped out by arriving humans.^[29] It is possible it may once have ranged across Vanuatu and Fiji as well. It is an uncommon to fairly common winter visitor to all parts of South Asia,^[30] and Southeast Asia from Myanmar through to Indochina and southern China, Indonesia, Malaysia and the Philippines.^[31]

Behaviour and ecology

Diet

Eating a fish

Fish make up 99% of the osprey's diet.^[32] It typically takes fish weighing 150–300 g (5.3–10.6 oz) and about 25–35 cm (9.8–13.8 in) in length, but the weight can range from 50 g (1.8 oz) to 2 kg (4.4 lb). Virtually any type of fish in that size range are taken.
Ospreys have vision that is well adapted to detecting underwater objects from the air. Prey is first sighted when the osprey is 10–40 m (33–131 ft) above the water, after which the bird hovers momentarily then plunges feet first into the water.^[33]
Occasionally, the osprey may prey on rodents, rabbits, hares, amphibians, other birds,^[34] and small reptiles.^[35]

Adaptations

The osprey has several adaptations that suit its piscivorous lifestyle :

• reversible outer toes^[36]
• sharp spicules on the underside of the toes^[36]
• closable nostrils to keep out water during dives
• backwards-facing scales on the talons which act as barbs to help hold its catch.
• dense plumage which is oily and prevents its feathers from getting waterlogged.^[37]

Reproduction

Preparing to mate on the nest

Osprey standing next to its nest showing their relative sizes

The osprey breeds near freshwater lakes and rivers, and sometimes on coastal brackish waters. Rocky outcrops just offshore are used in Rottnest Island off the coast of Western Australia, where there are 14 or so similar nesting sites of which five to seven are used in any one year. Many are renovated each season, and some have been used for 70 years. The nest is a large heap of sticks, driftwood, turf or seaweed built in forks of trees, rocky outcrops, utility poles, artificial platforms or offshore islets.^[32][38] As wide as 2 meters and weighing about 135 kg, large nests on utility poles may be fire hazards and have caused power outages.^[39]
Generally, ospreys reach sexual maturity and begin breeding around the age of three to four, though in some regions with high osprey densities, such as Chesapeake Bay in the U.S., they may not start breeding until five to seven years old, and there may be a shortage of suitable tall structures. If there are no nesting sites available, young ospreys may be forced to delay breeding. To ease this problem, posts are sometimes erected to provide more sites suitable for nest building.^[40] In some regions ospreys prefer transmission towers as nesting sites, e.g. in East Germany.^[41]

Egg, Collection Museum Wiesbaden

The platform design developed by one organization, Citizens United to Protect the Maurice River and Its Tributaries, Inc. has become the official design of the State of New Jersey, U.S. The platform plans and materials list, available online, have been utilized by people from a number of different geographical regions.^[42] Osprey-watch.org is the global site for mapping osprey nest locations and logging observations on reproductive success.^[43]
Ospreys usually mate for life. Rarely, polyandry has been recorded.^[44] The breeding season varies according to latitude; spring (September–October) in southern Australia, April to July in northern Australia and winter (June–August) in southern Queensland.^[38] In spring the pair begins a five-month period of partnership to raise their young. The female lays two to four eggs within a month, and relies on the size of the nest to conserve heat. The eggs are whitish with bold splotches of reddish-brown and are about 6.2 cm × 4.5 cm (2.4 in × 1.8 in) and weigh about 65 g (2.3 oz).^[38] The eggs are incubated for about 35–43 days to hatching.^[45]
The newly hatched chicks weigh only 50–60 g (1.8–2.1 oz), but fledge in 8–10 weeks. A study on Kangaroo Island, South Australia, had an average time between hatching and fledging of 69 days. The same study found an average of 0.66 young fledged per year per occupied territory, and 0.92 young fledged per year per active nest. Some 22% of surviving young either remained on the island or returned at maturity to join the breeding population.^[44] When food is scarce, the first chicks to hatch are most likely to survive. The typical lifespan is 7–10 years, though rarely individuals can grow to as old as 20–25 years.
The oldest European wild osprey on record lived to be over thirty years of age. In North America, great horned owls (Bubo virginianus), golden eagles (Aquila chrysaetos), and bald eagles (Haliaeetus leucocephalus) are the only major predators of ospreys, capable of taking both nestlings and adults.^{[35][46][47][48][49]} However, kleptoparasitism by bald eagles, where the larger raptor steals the osprey's catch, is more common than predation. The white-tailed eagle (Haliaeetus albicilla), which is very similar to the bald eagle, may harass or predate the osprey in Eurasia.^[50] Raccoons (Procyon lotor) can be a serious threat to nestlings or eggs if they can access the nest.^[51] Endoparasitic trematodes (Scaphanocephalus expansus and Neodiplostomum spp.) have been recorded in wild ospreys.^[52]

Migration

European breeders winter in Africa.^[53] American and Canadian breeders winter in South America, although some stay in the southernmost U.S. states such as Florida and California.^[54] Some ospreys from Florida migrate to South America.^[55] Australasian ospreys tend not to migrate.
Studies of Swedish ospreys showed that females tend to migrate to Africa earlier than the males. More stopovers are made during their autumn migration. The variation of timing and duration in autumn was more variable than in spring. Although migrating predominantly in the day, they sometimes fly in the dark hours particularly in crossings over water and cover on average 260–280 km (160–170 mi) per day with a maximum of 431 km (268 mi) per day.^[56] European birds may also winter in South Asia, an osprey ringed in Norway has been recovered in western India.^[57]

Status and conservation

Juvenile on a man-made nest

The osprey has a large range, covering 9,670,000 km² (3,730,000 sq mi) in just Africa and the Americas, and has a large global population estimated at 460,000 individuals. Although global population trends have not been quantified, the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e., declining more than 30% in ten years or three generations), and for these reasons, the species is evaluated as Least Concern.^[1] There is evidence for regional decline in South Australia where former territories at locations in the Spencer Gulf and along the lower Murray River have been vacant for decades.^[28]
In the late 19th and early 20th centuries, the main threats to osprey populations were egg collectors and hunting of the adults along with other birds of prey,^[35][58] but osprey populations declined drastically in many areas in the 1950s and 1960s; this appeared to be in part due to the toxic effects of insecticides such as DDT on reproduction.^[59] The pesticide interfered with the bird's calcium metabolism which resulted in thin-shelled, easily broken or infertile eggs.^[25] Possibly because of the banning of DDT in many countries in the early 1970s, together with reduced persecution, the osprey, as well as other affected bird of prey species, have made significant recoveries.^[32] In South Australia, nesting sites on the Eyre Peninsula and Kangaroo Island are vulnerable to unmanaged coastal recreation and encroaching urban development.^[28]

Cultural depictions

The Roman writer Pliny the Elder reported that parent ospreys made their young fly up to the sun as a test, and dispatched any that failed.^[60]
Another odd legend regarding this fish-eating bird of prey, derived from the writings of Albertus Magnus and recorded in Holinshed's Chronicles, was that it had one webbed foot and one taloned foot.^[58][61]
There was a medieval belief that fish were so mesmerised by the osprey that they turned belly-up in surrender,^[58] and this is referenced by Shakespeare in Act 4 Scene 5 of Coriolanus:

I think he'll be to Rome
As is the osprey to the fish, who takes it
By sovereignty of nature.

In Buddhism, the osprey is sometimes represented as the "King of Birds", especially in 'The Jātaka: Or, Stories of the Buddha’s Former Births' , no. 486.
The osprey is mentioned in the famous Chinese folk poem "guan guan ju jiu" (關關雎鳩); "ju jiu" 雎鳩 refers to the osprey, and "guan guan" (關關) to its voice. In the poem, the osprey is considered to be an icon of fidelity and harmony between wife and husband, due to its highly monogamous habits. Some commentators have claimed that "ju jiu" in the poem is not the osprey but the mallard duck, since the osprey cannot make the sound "guan guan".^[62][63]
So-called "osprey" plumes were an important item in the plume trade of the late 19th century and used in hats including those used as part of the army uniform. Despite their name, these plumes were actually obtained from egrets.^[64]
The Irish poet William Butler Yeats used a grey wandering osprey as a representation of sorrow in The Wanderings of Oisin and Other Poems (1889).^[60]
In heraldry, the osprey is typically depicted as a white eagle,^[61] often maintaining a fish in its talons or beak, and termed a "sea-eagle." It is historically regarded as a symbol of vision and abundance; more recently it has become a symbol of positive responses to nature,^[58] and has been featured on more than 50 international postage stamps.^[65]

Cap badge of the Selous Scouts was a stylized osprey

The cap badge of Rhodesia's Selous Scouts (1973-1980) was a stylized osprey.
In 1994, the osprey was declared the provincial bird of Nova Scotia, Canada.^[66] It is also the official bird of Södermanland, Sweden.
The osprey is used as a brand name for various products and sports teams. Examples include: the Ospreys (a Welsh Rugby team); the Richard Stockton College Ospreys (a NCAA Division III intercollegiate athletics team of the U.S. State of New Jersey); the first college in the nation (and the only one for many years) to adopt the osprey as its mascot and athletic team name, North Florida Ospreys (a NCAA Division I intercollegiate athletics team), the Missoula Osprey (a minor league baseball team); the Seattle Seahawks (an American football team of the National Football League); the Wagner Seahawks (a NCAA Division I intercollegiate athletics team); the Cold Spring Harbor Seahawks (a High school football team in Cold Spring Harbor, New York^[67]); the Peninsula High School Seahawks (a High School Football Team in Gig Harbor, Washington); and the St. Mary's College of Maryland Seahawks (a NCAA Division III intercollegiate athletics team).
Examples of the osprey used as a mascot include: Ozzie Osprey (of the University of North Florida); Talon the Osprey of New Jersey's Stockton University; Sammy the Seahawk (of University of North Carolina Wilmington); the Wells International Seahawks (of Bangkok, Thailand); the Salve Regina Seahawks (of Newport, Rhode Island); the LA Harbor College Seahawks (of South Bay); and Rowdy the Riverhawk (of the University of Massachusetts Lowell).^[68][69]



 Binomial name Pandion haliaetus
(Linnaeus, 1758)





 

THE ELK DEER

The elk or wapiti (Cervus canadensis) is one of the largest species within the deer family, Cervidae, in the world, and one of the largest land mammals in North America and Eastern Asia. This animal should not be confused with the still larger moose (Alces alces) to which the name "elk" applies in British English and in reference to populations in Eurasia.
Elk range in forest and forest-edge habitat, feeding on grasses, plants, leaves, and bark. Male elk have large antlers which are shed each year. Males also engage in ritualized mating behaviors during the rut, including posturing, antler wrestling (sparring), and bugling, a loud series of vocalizations that establishes dominance over other males and attracts females.
Although they are native to North America and eastern Asia, they have adapted well to countries in which they have been introduced, including Argentina and New Zealand. Their great adaptability may threaten endemic species and ecosystems into which they have been introduced.
Elk are susceptible to a number of infectious diseases, some of which can be transmitted to livestock. Efforts to eliminate infectious diseases from elk populations, largely by vaccination, have had mixed success.
Some cultures revere the elk as a spiritual force. In parts of Asia, antlers and their velvet are used in traditional medicines. Elk are hunted as a game species. The meat is leaner and higher in protein than beef or chicken.^[3]
It was long believed to be a subspecies of the European red deer (Cervus elaphus), but evidence from a number of mitochondrial DNA genetic studies beginning in 1998 show that the two are distinct species.^[4][5][6][7] Key morphological differences that distinguish C. canadensis from C. elaphus are the former's wider rump patch and paler-hued antlers.^[8]

 

 Elk (male)

 

 

  Elk (female)

Naming and etymology

 



Early European explorers in North America, who were familiar with the smaller red deer of Europe, thought that the larger North American animal resembled a moose, and consequently gave it the name elk, which is the common European name for moose. The word elk is related to the Latin alces, Old Norse elgr, Scandinavian elg/älg and German Elch, all of which refer to the animal known in North America as the moose.^[9]
The name wapiti is from the Shawnee and Cree word waapiti, meaning "white rump".^[10] This name is used in particular for the Asian subspecies (Altai wapiti, Tian Shan wapiti, Manchurian wapiti and Alashan wapiti), because in Eurasia the name elk continues to be used for the moose.
Wapiti is also the preferred name for the species in New Zealand.
Asian subspecies are sometimes referred to as the maral, but this name applies primarily to the Caspian red deer (Cervus elaphus maral), a subspecies of red deer. There is a subspecies of elk in Mongolia called the Altai wapiti (Cervus canadensis sibiricus),^[11] also known as the Altai maral.

 

 

Taxonomy

Elk crossing a rock face

Members of the genus Cervus (and hence early relatives or possible ancestors of the elk) first appear in the fossil record 25 million years ago, during the Oligocene in Eurasia, but do not appear in the North American fossil record until the early Miocene.^[12] The extinct Irish elk (Megaloceros) was not a member of the genus Cervus, but rather the largest member of the wider deer family (Cervidae) known from the fossil record.^[13]
Until recently, red deer and elk were considered to be one species, Cervus elaphus.^[11][14] However, mitochondrial DNA studies, conducted on hundreds of samples in 2004 from red deer and elk subspecies as well as other species of the Cervus deer family, strongly indicate that elk, or wapiti, should be a distinct species, namely Cervus canadensis.^[6] The previous classification had over a dozen subspecies under the C. elaphus species designation; DNA evidence concludes that elk are more closely related to Thorold's deer and even sika deer than they are to the red deer.^[6] Elk and red deer produce fertile offspring in captivity, and the two species have freely inter-bred in New Zealand's Fiordland National Park, where the cross-bred animals have all but removed the pure elk blood from the area.^[15]

 

 

Subspecies

 


There are numerous subspecies of elk described, with six from North America and four from Asia, although some taxonomists consider them different ecotypes or races of the same species (adapted to local environments through minor changes in appearance and behavior). Populations vary as to antler shape and size, body size, coloration and mating behavior. DNA investigations of the Eurasian subspecies revealed that phenotypic variation in antlers, mane and rump patch development are based on "climatic-related lifestyle factors".^[16] Of the six subspecies of elk known to have inhabited North America in historical times, four remain, including the Roosevelt (C. canadensis roosevelti), tule (C. canadensis nannodes), Manitoban (C. canadensis manitobensis) and Rocky Mountain (C. canadensis nelsoni).^[17] The eastern elk (C. canadensis canadensis) and Merriam's elk (C. canadensis merriami) subspecies have been extinct for at least a century.^[18][19]
Four subspecies described in Asia include the Altai wapiti (C. canadensis sibiricus) and the Tianshan wapiti (C. canadensis songaricus). Two distinct subspecies found in China and Korea are the Manchurian wapiti (C. canadensis xanthopygus) and the Alashan wapitis (C. canadensis alashanicus). The Manchurian wapiti is darker and more reddish in coloration than the other populations. The Alashan wapiti of north central China is the smallest of all subspecies, has the lightest coloration and is the least studied.^[15] Biologist Valerius Geist, who has written on the world's various deer species, holds that there are only three subspecies of elk. Geist recognizes the Manchurian and Alashan wapiti but places all other elk into C. canadensis canadensis, claiming that classification of the four surviving North American groups as subspecies is driven, at least partly, for political purposes to secure individualized conservation and protective measures for each of the surviving populations.^[20]
Recent DNA studies suggest that there are no more than three or four subspecies of elk. All American forms aside from possibly the tule and Roosevelt elk seem to belong to one subspecies (Cervus canadensis canadensis). Even the Siberian elk (Cervus canadensis sibiricus) are more or less identical to the American forms and therefore may belong to this subspecies, too. However the Manchurian wapiti (Cervus canadensis xanthopygus) is clearly distinct from the Siberian forms, but not distinguishable from the Alashan wapiti. The Chinese forms MacNeill's deer, Kansu red deer, and Tibetan red deer belong also to the wapitis and were not distinguishable from each other by mitochondrial DNA studies.^[6] These Chinese subspecies are sometimes treated as a distinct species, namely the Central Asian red deer (Cervus wallichi), which also includes the Kashmir stag.^[21]

• Northern and American group
  • Roosevelt elk (C. c. roosevelti)
  • Tule elk (C. c. nannodes)
  • Manitoban elk (C. c. manitobensis)
  • Rocky Mountain elk (C. c. nelsoni)
  • Eastern elk (C. c. canadensis; extinct)
  • Merriam's elk (C. c. merriami; extinct)
• Eastern group
  • Altai wapiti (C. c. sibiricus)
  • Tian Shan wapiti (C. c. songaricus)
  • Manchurian wapiti (C. c. xanthopygus)
  • Alashan wapiti (C. c. alashanicus)
• Southern group (Central Asian red deer)
  • MacNeill's deer (C. c. macneilli)
  • Kansu red deer (C. c. kansuensis)
  • Tibetan red deer (C. c. wallichii)
  • Kashmir stag (C. c. hanglu)

• 

  Illustration of eastern elk
• 

  Illustration of Altai wapiti
• 

  Illustration of Manchurian wapiti
• 

  Illustration of Kashmir stag

Anatomy

A herd of Roosevelt elk

The elk is a large animal of the ungulate order Artiodactyla, possessing an even number of toes on each foot, similar to those of camels, goats and cattle. It is a ruminant species, with a four-chambered stomach, and feeds on grasses, plants, leaves and bark. During the summer, elk eat almost constantly, consuming between 4 and 7 kilograms (8.8 and 15.4 lb) of vegetation daily.^[22] In North America, males are called bulls, and females are called cows. In Asia, stag and hind, respectively, are sometimes used instead.
Elk are more than twice as heavy as mule deer and have a more reddish hue to their hair coloring, as well as large, buff-colored rump patches and smaller tails. Moose are larger and darker than elk; bulls have distinctively different antlers. Elk gather in herds, while moose are solitary. Elk cows average 225 to 241 kg (496 to 531 lb), stand 1.3 m (4.3 ft) at the shoulder, and are 2.1 m (6.9 ft) from nose to tail. Bulls are some 40% larger than cows at maturity, weighing an average of 320 to 331 kg (705 to 730 lb), standing 1.5 m (4.9 ft) at the shoulder and averaging 2.45 m (8.0 ft) in length.^[23][24] The largest of the subspecies is the Roosevelt elk (C. c. roosevelti), found west of the Cascade Range in the U.S. states of California, Oregon and Washington, and in the Canadian province of British Columbia. Roosevelt elk have been reintroduced into Alaska, where the largest males are estimated to weigh up to 600 kg (1,300 lb).^[25] More typically, male Roosevelt elks weigh around 300 to 544 kg (661 to 1,199 lb), while females weigh 260 to 285 kg (573 to 628 lb).^[26][27] The smallest-bodied race is the tule elk (C. c. nannodes), which weighs from 170 to 250 kg (370 to 550 lb) in both sexes.^[26]
Only the males have antlers, which start growing in the spring and are shed each winter. The largest antlers may be 1.2 metres (3.9 ft) long and weigh 18 kilograms (40 lb).^[28] Antlers are made of bone which can grow at a rate of 2.5 centimetres (0.98 in) per day. While actively growing, the antlers are covered with and protected by a soft layer of highly vascularised skin known as velvet. The velvet is shed in the summer when the antlers have fully developed. Bull elk may have eight or more tines on each antler; however, the number of tines has little to do with the age or maturity of a particular animal. The Siberian and North American elk carry the largest antlers while the Altai wapiti have the smallest.^[15] The formation and retention of antlers is testosterone-driven.^[29] After the breeding season in late fall, the level of pheromones released during estrus declines in the environment and the testosterone levels of males drop as a consequence. This drop in testosterone leads to the shedding of antlers, usually in the early winter.

Rocky Mountain elk

During the fall, elk grow a thicker coat of hair, which helps to insulate them during the winter. Males, females and calves of Siberian and North American elk all grow thin neck manes; female and young Manchurian and Alaskan wapitis do not.^[20] By early summer, the heavy winter coat has been shed, and elk are known to rub against trees and other objects to help remove hair from their bodies. All elk have small and clearly defined rump patches with short tails. They have different coloration based on the seasons and types of habitats, with gray or lighter coloration prevalent in the winter and a more reddish, darker coat in the summer. Subspecies living in arid climates tend to have lighter colored coats than do those living in forests.^[30] Most have lighter yellow-brown to orange-brown coats in contrast to dark brown hair on the head, neck, and legs during the summer. Forest-adapted Manchurian and Alaskan wapitis have darker reddish-brown coats with less contrast between the body coat and the rest of the body during the summer months.^[15] Calves are born spotted, as is common with many deer species, and they lose their spots by the end of summer. Adult Manchurian wapiti may retain a few orange spots on the back of their summer coats until they are older. This characteristic has also been observed in the forest-adapted European red deer.^[15]

 

 

Behavior

	An American elk bugling Menu 0:00
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A bison charges an elk near Old Faithful in Yellowstone National Park.

Adult elk usually stay in single-sex groups for most of the year. During the mating period known as the rut, mature bulls compete for the attentions of the cow elk and will try to defend females in their harem. Rival bulls challenge opponents by bellowing and by paralleling each other, walking back and forth. This allows potential combatants to assess the other's antlers, body size and fighting prowess.^[31] If neither bull backs down, they engage in antler wrestling, and bulls sometimes sustain serious injuries. Bulls also dig holes in the ground called wallows, in which they urinate and roll their body.^[32] A male elk's urethra points upward so that urine is sprayed almost at a right angle to the penis.^[33] The urine soaks into their hair and gives them a distinct smell which attracts cows.^[32]
Dominant bulls follow groups of cows during the rut, from August into early winter. A bull will defend his harem of 20 cows or more from competing bulls and predators.^[34] Only mature bulls have large harems and breeding success peaks at about eight years of age. Bulls between two and four years and over 11 years of age rarely have harems, and spend most of the rut on the periphery of larger harems. Young and old bulls that do acquire a harem hold it later in the breeding season than do bulls in their prime. A bull with a harem rarely feeds and he may lose up to 20 percent of his body weight. Bulls that enter the rut in poor condition are less likely to make it through to the peak conception period or have the strength to survive the rigors of the oncoming winter.^[31]
Bulls have a loud vocalization consisting of screams known as bugling, which can be heard for miles. Bugling is often associated with an adaptation to open environments such as parklands, meadows, and savannas, where sound can travel great distances. Females are attracted to the males that bugle more often and have the loudest call.^[35] Bugling is most common early and late in the day and is one of the most distinctive sounds in nature, akin to the howl of the gray wolf.

 

 

Reproduction and lifecycle

 

 Further information: Rut (mammalian reproduction) § Elk

Female nursing young

Female elk have a short estrus cycle of only a day or two, and matings usually involve a dozen or more attempts. By the autumn of their second year, females can produce one and, very rarely, two offspring, although reproduction is most common when cows weigh at least 200 kilograms (440 lb).^[36] The gestation period is 240 to 262 days and the offspring weigh between 15 and 16 kilograms (33 and 35 lb). When the females are near to giving birth, they tend to isolate themselves from the main herd, and will remain isolated until the calf is large enough to escape predators.^[32] Calves are born spotted, as is common with many deer species, and they lose their spots by the end of summer. Manchurian wapiti may retain a few orange spots on the back of their summer coats until they are older. After two weeks, calves are able to join the herd, and are fully weaned at two months of age.^[37] Elk calves are as large as an adult white-tailed deer by the time they are six months old.^[38] The offspring will remain with their mothers for almost a year, leaving about the time that the next season's offspring are produced.^[35] The gestation period is the same for all subspecies.
Elk live 20 years or more in captivity but average 10 to 13 years in the wild. In some subspecies that suffer less predation, they may live an average of 15 years in the wild.^[39]

Predators and defensive tactics

Single bull elk are vulnerable to predation by wolves

In North America, wolf and coyote packs and the solitary cougar are the most likely predators, although brown and black bears also prey on elk.^[35] Coyote packs mostly prey on elk calves, though they can sometimes take a winter- or disease-weakened adult.^[40] In the Greater Yellowstone Ecosystem which includes Yellowstone National Park, bears are the most significant predators of calves.^[41] Major predators in Asia include the wolf, dhole, brown bear, Siberian tiger, Amur leopard, and snow leopard. Eurasian lynx and wild boar sometimes prey on Asian elk calves.^[15] Historically, tigers in the Lake Baikal region fed on Manchurian wapiti, and continue to do so in the Amur region.^[42]
Male elk retain their antlers for more than half the year and are less likely to group with other males when they have antlers. Antlers provide a means of defense, as does a strong front-leg kick, which is performed by either sex if provoked. Once the antlers have been shed, bulls tend to form bachelor groups which allow them to work cooperatively at fending off predators. Herds tend to employ one or more scouts while the remaining members eat and rest.^[35]
After the rut, females form large herds of up to 50 individuals. Newborn calves are kept close by a series of vocalizations; larger nurseries have an ongoing and constant chatter during the daytime hours. When approached by predators, the largest and most robust females may make a stand, using their front legs to kick at their attackers. Guttural grunts and posturing effectively deter all but the most determined predators.
Wapiti in New Zealand have no natural predators.^[43]

Migration

Elk wintering in Jackson Hole, Wyoming, after migrating there during the fall

As is true for many species of deer, especially those in mountainous regions, elk migrate into areas of higher altitude in the spring, following the retreating snows, and the opposite direction in the fall. Hunting pressure also impacts migration and movements.^[44] During the winter, they favor wooded areas and sheltered valleys for protection from the wind and availability of tree bark to eat. Roosevelt elk are generally non-migratory due to less seasonal variability of food sources.^[35]
The Greater Yellowstone Ecosystem elk herd numbers over 200,000 individuals and during the spring and fall, they take part in the longest elk migration in the continental U.S. Elk in the southern regions of Yellowstone National Park and in the surrounding National Forests migrate south towards the town of Jackson, Wyoming, where they winter for up to six months on the National Elk Refuge. Conservationists there ensure the herd is well fed during the harsh winters.^[45] Many of the elk that reside in the northern sections of the Greater Yellowstone Ecosystem migrate to lower altitudes in Montana, mainly to the north and west.

Diet

Elk pellet group

Elk are ruminants and therefore have four-chambered stomachs. Unlike white-tailed deer and moose which are primarily browsers, elk have a similarity to cattle as they are primarily grazers, but like other deer, they also browse.^[46][47] Elk have a tendency to do most of their feeding in the mornings and evenings, seeking sheltered areas in between feedings to digest. Their diets vary somewhat depending on the season, with native grasses being a year-round supplement, tree bark being consumed in winter and forbs and tree sprouts during the summer. Elk consume an average of 9.1 kilograms (20 lb) of various vegetation daily.^[48] Particularly fond of aspen sprouts which rise in the spring, elk have had some impact on aspen groves which have been declining in some regions where elk exist.^[49]
Range and wildlife managers conduct surveys of elk pellet groups to monitor populations and resource use.^[50][51]

Parasites and disease

At least 53 species of protist and animal parasites have been identified in elk.^[52] Most of these parasites seldom lead to significant mortality among wild or captive elk. Parelaphostrongylus tenuis (brainworm or meningeal worm) is a parasitic nematode known to affect the spinal cord and brain tissue of elk and other species, leading to death.^[53] The definitive host is the white-tailed deer, in which it normally has no ill effects. Snails and slugs, the intermediate hosts, can be inadvertently consumed by elk during grazing.^[9] The liver fluke Fascioloides magna and the nematode Dictyocaulus viviparus are also commonly found parasites that can be fatal to elk.^[54] Since infection by either of these parasites can be lethal to some commercial livestock species, their presence in elk herds is of some concern.

A bull elk in spring, shedding its winter coat and with its antlers covered in velvet

Chronic wasting disease, transmitted by a misfolded protein known as a prion, affects the brain tissue in elk, and has been detected throughout their range in North America. First documented in the late 1960s in mule deer, the disease has affected elk on game farms and in the wild in a number of regions. Elk that have contracted the disease begin to show weight loss, increased watering needs, disorientation and listlessness, and at an advanced stage the disease leads to death. The disease is similar to but not the same as mad cow disease, and no risks to humans have been documented, nor has the disease been demonstrated to pose a threat to domesticated cattle.^[55] In 2002, South Korea banned the importation of elk antler velvet due to concerns about chronic wasting disease.^[56]
The Gram-negative bacterial disease brucellosis occasionally affects elk in the Greater Yellowstone Ecosystem, the only place in the U.S. where the disease is still known to exist. In domesticated cattle, brucellosis causes infertility, abortions and reduced milk production. It is transmitted to humans as undulant fever, producing flu-like symptoms which may last for years. Though bison are more likely to transmit the disease to other animals, elk inadvertently transmitted brucellosis to horses in Wyoming and cattle in Idaho. Researchers are attempting to eradicate the disease through vaccinations and herd management measures, which are expected to be successful.^[57] Nevetheless, research has been ongoing since 2002, and a successful vaccine has yet to be developed as of 2016.^[58]
A recent necropsy study of captive elk in Pennsylvania attributed the cause of death in 33 of 65 cases to either gastrointestinal parasites (21 cases, primarily Eimeria sp. and Ostertagia sp.) or bacterial infections (12 cases, mostly pneumonia).^[59]
Elk hoof disease was first noticed in the state of Washington in the late 1990s in the Cowlitz River basin, with sporadic reports of deformed hooves. Since then the disease has spread rapidly with increased sightings throughout South West Washington and into Oregon. The disease is characterised by deformed, broken or missing hooves and leads to severe lameness in elk. The primary cause is not known but it is associated with Treponeme bacteria which are known to cause digital dermatitis in commercial livestock. The mode of transmission is also not known but it appears to be highly contagious amongst elk. Studies are being undertaken by government department to determine how to halt or eliminate the disease.^[60][61][62]

Ecology

Distribution

Bull elk bugling during the rut

Modern subspecies are descended from elk that once inhabited Beringia, a steppe region between Asia and North America that connected the two continents during the Pleistocene. Beringia provided a migratory route for numerous mammal species, including brown bear, camel, horse, caribou, and moose, as well as humans.^[63] As the Pleistocene came to an end, ocean levels began to rise; elk migrated southwards into Asia and North America. In North America they adapted to almost all ecosystems except for tundra, true deserts, and the gulf coast of the U.S. The elk of southern Siberia and central Asia were once more widespread but today are restricted to the mountain ranges west of Lake Baikal including the Sayan and Altai Mountains of Mongolia and the Tianshan region that borders Kyrgyzstan, Kazakhstan, and China's Xinjiang Province.^[1] The habitat of Siberian elk in Asia is similar to that of the Rocky Mountain subspecies in North America.
Throughout their range, they live in forest and in forest edge habitat, similar to other deer species. In mountainous regions, they often dwell at higher elevations in summer, migrating down slope for winter. The highly adaptable elk also inhabit semi-deserts in North America, such as the Great Basin. Manchurian and Alashan wapiti are primarily forest dwellers and their smaller antler size is a likely adaptation to a forest environment.

Bull elk at Big Spring Creek in Great Sand Dunes National Park

Introductions

Bull elk on a captive range in Nebraska. These elk, originally from Rocky Mountain herds, exhibit modified behavior due to having been held in captivity, under less selective pressure

The Rocky Mountain elk subspecies has been reintroduced by hunter-conservation organizations in the Appalachian region of the eastern U.S., where the now extinct eastern elk once lived^[64] After elk were reintroduced in the states of Kentucky, North Carolina and Tennessee, they migrated into the neighboring states of Virginia and West Virginia, and have established permanent populations there.^[65] In 2017, a male elk, likely from the Smoky Mountains population, was sighted in South Carolina for the first time in nearly 300 years.^[66] Elk have also been reintroduced to a number of other states, including Pennsylvania,^[67][68] Michigan, Wisconsin, Missouri ^[69] and Etolin and Afognak Islands in Alaska.^[70] Reintroduction of the elk into Ontario began in the early 20th century, and is still ongoing due to the limited success.^[71] As of 1989, population figures for the Rocky Mountain subspecies were 782,500, and estimated numbers for all North American subspecies exceeded 1 million.^[72] Prior to the European colonization of North America, there were an estimated 10 million elk on the continent.^[23]
Outside their native habitat, elk and other deer species, especially white tails, were introduced in areas that previously had few if any large native ungulates. Brought to these countries for hunting and ranching for meat, hides and antler velvet, they have proven highly adaptable and have often had an adverse impact on local ecosystems. Elk and red deer were introduced to Argentina in the early 20th century.^[73] There they are now considered an invasive species, encroaching on Argentinian ecosystems where they compete for food with the indigenous Chilean huemul and other herbivores.^[74] This negative impact on native animal species has led the IUCN to identify the elk as one of the world's 100 worst invaders.^[75]
The introduction of deer to New Zealand began in the middle of the 19th century, and current populations are primarily European red deer, with only 15 percent being elk.^[76] There is significant hybridization of elk with the more numerous red deer to the extent that pure elk may no longer exist in the wild in New Zealand. These deer have had an adverse impact on forest regeneration of some plant species, as they consume more palatable species which are replaced with those that are less favored by the elk. The long-term impact will be an alteration of the types of plants and trees found, and in other animal and plant species dependent upon them.^[77] As in Chile and Argentina, the IUCN has declared that red deer and elk populations in New Zealand are an invasive species.^[75]

Cultural references

A Kiowa couple. The woman on the right is wearing an elk tooth dress.

Elk have played an important role in the cultural history of a number of peoples. Pictograms and petroglyphs of elk were carved into cliffs thousands of years ago by the Anasazi of the southwestern U.S. More recent Native American tribes, including the Kootenai, Cree, Blackfeet, Ojibwa and Pawnee, produced blankets and robes from elk hides. The elk was of particular importance to the Lakota, and played a spiritual role in their society.^[78] At birth, Lakota males were given an elk's tooth to promote a long life since that was seen as the last part of dead elk to rot away. The elk was seen as having strong sexual potency and young Lakota males who had dreamed of elk would have an image of the mythical representation of the elk on their "courting coats" as a sign of sexual prowess. The Lakota believed that the mythical or spiritual elk, not the physical one, was the teacher of men and the embodiment of strength, sexual prowess and courage.
Neolithic petroglyphs from Asia depict antler-less female elk, which have been interpreted as symbolizing rebirth and sustenance. By the beginning of the Bronze Age, the elk is depicted less frequently in rock art, coinciding with a cultural transformation away from hunting.^[79]
The Rocky Mountain elk is the official state animal for Utah.^[80] An image of an elk and a moose appear on the state seal and flag of Michigan.^[81] The Benevolent and Protective Order of Elks (B.P.O.E.) chose the elk as its namesake because a number of its attributes seemed appropriate for cultivation by members of the fraternity. A representation of the majestic head of the male, with its spreading antlers, was adopted as the first badge of the Order; and is still the most conspicuous element of its copyrighted fraternal emblem.^[82] A prized possession of many members of the B.P.O.E. are jewel encrusted, gold mounted elk teeth – which are actually ivory.^[83]

Commercial uses

Approximately 0.45 kg (1 lb) of ground elk meat formed into patties; they have relatively low fat content

Although breakdown figures for each game species are not available in the 2006 National Survey from the U.S. Fish and Wildlife Service, hunting of wild elk is most likely the primary economic impact.^[84]
Elk are held in captivity, or farmed, for hunting, meat production and velvet collection. In what is known as a canned hunt, a hunter pays a fee for an essentially guaranteed chance to shoot an elk in an escape-proof range. While elk are not generally harvested for meat production on a large scale, some restaurants offer the meat as a specialty item and it is also available in some grocery stores. The meat has a taste somewhere between beef and venison and is higher in protein and lower in fat and cholesterol than beef, pork, and chicken.^[85] Elk meat is also a good source of iron, phosphorus and zinc.^[86]
A male elk can produce 10 to 11 kilograms (22 to 24 lb) of antler velvet annually and on ranches in the United States, Canada and New Zealand, this velvet is collected and sold to markets in East Asia, where it is used in medicine. Velvet is also considered by some cultures to be an aphrodisiac.^[56] However, consuming velvet from elk in North America may be risky since velvet from animals infected with chronic wasting disease may contain prions that could result in a human getting variant Creutzfeldt–Jakob disease.^[87]
Antlers are also used in artwork, furniture and other novelty items. All Asian subspecies, along with other deer, have been raised for their antlers in central and eastern Asia by Han Chinese, Turkic peoples, Tungusic peoples, Mongolians, and Koreans. Elk farms are relatively common in North America and New Zealand.^[76]
Elk hides have been used for thousands of years for tepee covering, blankets, clothing and footwear. Modern uses are more decorative, but elk skin shoes, gloves and belts are not uncommon.^[23]
Since 1967, the Boy Scouts of America have assisted employees at the National Elk Refuge in Wyoming by collecting the antlers which are shed each winter. The antlers are then auctioned with 80% of the proceeds returned to the refuge. In 2010, 2,520 kilograms (5,560 lb) of antlers were auctioned, bringing in over $46,000.^[88]