Osprey - Pandion haliaetus

Osprey

Pandion haliaetus

Order : Accipitriformes

Family : Pandionidae ;

1 autre fiche de cette famille.
French version
Osprey

Biometrics :

Size : 55 à 69 cm
Wingspan : 145 à 170 cm
Weight : M:1200 à 1600 gr- F: 1600 à 2000gr

Longevity : 32 years

IUCN conservation status :

Extinct

Threatened

Least
concern

Extinc
in the Wild

Near
threatened

Not
evaluated

EX EW CR EN VU NT LC NE

Geographic range :

Synonyms : Skopa (ru), Fiskgjuse (sv), Águila pescadora (es), Falco pescatore (it), Fischadler (al), Visarend (nl), Osprey (en)

Physical description :
Osprey is a large bird of prey. It has dark brown plumage on upperparts. Underparts are white, with dark brown small spots on upper breast, as a necklace. Tail is brown barred with white. Long wings are white below, with dark brown patch at the carpal joint.
Head is white, with conspicuous dark brown eye-stripes. We can see longer feathers on nape. Hooked bill is black. Eyes are yellow. Legs and feet are pale blue-grey.
Both sexes are almost similar in plumage, but female is slightly larger than male, and has darker streaking on upper breast, and darker plumage.
Juvenile has dark brown plumage, with pale buff edges above. It has duller brown plumage than adult female. Its breast's necklace is not very conspicuous. Eyes are orange-red, not yellow.
Some variations in size and colour can be observed. Tropical and subtropical birds are smaller than those from higher latitudes.

Voice :
Sound from CD 'Tous les Oiseaux d'Europe' by Jean C. Roché by courtesy of Sittelle and CEBA. Osprey is usually silent, but they use vocalizations for begging food, alarm, courtship and defence.
Alarm call is a series of hoarse and descending whistles 'piu-piu-piu-piu'. During flight displays, male utters a series of mournful whistles 'yeelp-yeelp-yeelp'. And we can hear series of loud whistled 'kyews'.

Habitat : Osprey needs shallow water and safe nest site to live. We find it in freshwater or brackish lakes, lagoons, estuaries and rivers. It nests in adjacent forests, but in some parts of its Mediterranean range, it breeds only on sea coasts, on cliffs or small islets.
GEOGRAPHIC RANGE: Ospreys have a worldwide distribution, except Antarctica. They breed in North America, Eurasia (when migratory), Middle-East, North Eastern Africa, Australia and Indonesia. They may be migratory or sedentary.
They winter southwards to South America, Africa, India, Southern Asia and Australia.

Behaviour : Osprey feeds on fish, captured in shallow waters, or near the surface in deeper waters. Osprey hunts for fish on the wing, flapping and gliding at about 10 to 40 metres above the surface. When it locates a prey, it hovers briefly, and dives towards the surface. Just before to hit the water, it swings its legs forwards and bends the wings backwards, and plunges feet-first into the water. Then, Osprey carries the fish with one leg in front of the other, to put the fish face forwards, it is easier to carry it.
Osprey brings the fish to a perch to eat. Usually, it begins with the head and continues towards the tail.
Breeding season differs between populations. Non migratory birds breed in winter and spring, and migratory birds breed in spring and summer.
Male performs elaborate aerial displays during courtship and early incubation. One if these flight displays is named 'sky-dance'. Male brings a fish or some nest materials. It gives screaming calls while performs undulating flights alternated with hovering.
Osprey defends its nest or nest-site, giving alarm calls when predator, intruder or disturbances (boat or humans) approach the nest. It also adopts an erect posturing and diving flight.

Flight : Osprey soars less often than most raptors. It glides with well raised arms and hand lowered. When it performs active flight, it has powerful but loose and shallow wing beats.
To carry its large prey, Osprey uses strong, horizontal wing beats to lift itself and the fish from the water.

Reproduction-nesting : Osprey's nest is located in dead tree or artificial nest platform. But it can nest on man-made structures such as poles, towers, buildings and others. They need structures that can support the bulky nest.
Both sexes collect materials. Nest is made with sticks, and lined with soft materials such as kelp, grasses or even cardboard. But we can also find fishing line, plastic bags and many other artificial items in the nest.
Pair use the same nest every year, adding material before clutch be laid.
Female lays 2 to 4 eggs in several days, one to two days apart. Incubation lasts about 40 days, shared by both parents. Incubation starts with the first egg laid. Male delivers food to female until the young fledge. It is a good manner to keep its mate, and protect its paternity. Male guards its mate from other males and copulates frequently before egg laying.
A chick that hatches first is larger than the others. If food is scarce, the smallest often dies. This process is named brood reduction. Both parents feed the young. Male brings food to female and chicks, about 3 to 10 fishes per day. One of the adults tears pieces from the fish to feed the chicks. Both parents feed and protect their young from predators and weather. Female broods them the first two weeks, and then, during bad weather.
Chicks are covered with white down when they hatch, changing in dark brown down at about 10 days. Feathers need two weeks to replace down.
Young fledge between 50 to 75 days after hatching. They begin to hunt on their own, but parents continue to feed them at nest, for some weeks more.
Young reach their sexual maturity at about 3 to 5 years old.
This species produces one brood per year.

Food habits : Osprey feeds mainly on fish. But sometimes, it may consume birds, snakes, small rodents and salamanders.

Protection / threats : Ospreys have nest predators such as raccoons and snakes, but also aerial predators such as owls and eagles.
In early 20th century, populations declined by egg collectors, shootings, and also pesticides. But now, after the banning of DDT, populations largely rebounded, and artificial nest structures help these raptors to breed quietly, and this species increases and expands its range.

Other links :
Iucn
Birdlife

Specification sheet created by Nicole Bouglouan

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