Ospreys (Pandion haliaetus) are cosmopolitan birds of prey that have different migration routes across the globe. They are expert fish hunters that can be found patrolling up and down rivers and estuaries or hunting over lakes and bays. Their overwintering grounds are frequently completely different in nature from their breeding sites.
Most populations of ospreys are migratory. They breed in the northern hemisphere, traveling south for the winter to escape harsh weather and enjoy rich fishing grounds. In the spring, these remarkable birds usually return to nest in the same place, and with the same partner, year after year.
Osprey migration is a well-studied and amazing phenomenon that takes place on almost every continent on earth. Read along as we cover the fascinating osprey migration in more detail!
The migration of Ospreys is a fascinating topic
Ospreys are highly migratory birds of prey. They migrate to and from every continent on earth, with the exception of Australia and Antarctica. Most populations of ospreys are migratory, although there are resident populations too.
Ospreys from different parts of the world migrate to different areas and use different routes to get there. Birds that breed in Oregon and the Pacific Northwest, for example, migrate south to overwinter in Mexico and other parts of Central America. Ospreys that breed in the United Kingdom also migrate long distances, spending the winter in West Africa.
Read on to learn more about when, how, and why these birds migrate.
Most ospreys migrate in the fall, flying south to spend the winter in the Southern hemisphere, or at least closer to the equator. They return to nest in the following spring, when the days get longer and temperatures begin to rise.
In the United States, ospreys begin their migration in the fall. The actual date varies, usually between July and September. Females typically begin their migration (and arrive at their overwintering grounds) ahead of males. The return trip from overwintering happens the following spring, with individuals arriving back at their breeding grounds between March and May depending on locality.
Ospreys in the United Kingdom follow a similar schedule. This population typically departs for West Africa by September and returns by late March or early April. The exact timing of arrival and departure varies according to latitude and even weather conditions.
Osprey in flight, pictured from below
Ospreys migrate to avoid facing the challenges of survival in winter. Long-distance migration comes at a great cost as far as energy is concerned, and is also a risky move with some birds never making their overwintering grounds. Migration is essential for these birds, however, to escape freezing conditions and dwindling food resources.
The distances that ospreys migrate vary greatly across the globe. Some of the longest distances traveled are by northern and eastern European populations that overwinter in South Africa.
Ospreys migrating from Sweden, for example, were shown to travel an average distance of 6,700km (4,200mi) on their migration to Africa. One young bird that fledged in Massachusetts, USA, traveled 4,345km (2,700 mi) to French Guiana in South America on its first migration.
A close up of an Osprey in flight, Cairngorms National Park, Scotland
Ospreys migrate north and south between many different parts of the world. Amazingly, the areas where they spend the winter often look nothing like their summer breeding grounds! These birds depend on fish to survive, so they migrate between rivers, lakes, and coastal areas on either side of the equator.
Ospreys that breed in the northeastern part of the United States migrate south to South American countries like Brazil and Venezuela. Over on the West Coast, Ospreys migrate south into Central America and may travel as far as Argentina.
In The United Kingdom, ospreys also migrate south for the winter, flying across the Mediterranean and western Sahara to spend the winter in warmer countries like Gambia and Senegal in West Africa.
Ospreys depend on fish for their diets
Migration time varies between different ospreys because various populations and individuals fly differing distances. Individual ospreys even take different routes. Northern European ospreys can take six weeks to migrate to Southern Africa, but American birds usually complete their migration in two to four weeks.
Ospreys are usually not able to complete their migrations in one go. They will make many stops along the way during their migration to hunt and rest, often spending several days at a time at various locations. Studies have shown that they travel 95-380 kilometers (59-236mi) per day, but they can travel much further in a single flight when necessary.
Sometimes, stopping to rest is just not an option. Ospreys that migrate between the northeastern United States and Brazil, for example, must travel considerable distances over the Atlantic ocean. In this case, distances of up to 2,400km (1,491mi) and flight times of 54 hours have been reported!
An Osprey soaring through the sky
Ospreys usually migrate on their own, although they have been known to travel in small groups of two to four individuals. In some places like islands where migrating birds naturally converge, as many as 92 ospreys have been seen together.
Ospreys mate for life and pairs will return to the same nest site year after year. The pair arrive at their breeding grounds at different times, however.
A mating pair of Ospreys perched together in a tree
Not all populations of osprey are migratory. In fact, you can find resident ospreys in many parts of the world, including parts of the United States. These areas do not see seasonal climate changes that are marked enough to force migration.
In southern Florida and southern California, conditions are suitable for sustaining ospreys throughout the year. Similar conditions occur around much of the Australian coast and in parts of the Mediterranean region.
Migratory ospreys travel south during the Northern hemisphere winter. North American birds travel south to Central and South America, while British ospreys migrate to West Africa.
During the non-breeding season, ospreys can be found throughout much of Africa, all the way to the southernmost parts of South Africa. Central Asian populations also fly south for the winter and can be found overwintering in south-east Asia the Indian sub-continent.
An Osprey diving for fish
In the northern hemisphere summer, ospreys can be found right across North America, Europe, and Asia. These birds are always found near water where they hunt for fish.
In The USA, ospreys can turn up just about anywhere on migration, although they do not breed across much of the interior. In the UK, ospreys have made a return after being driven to extinction in the early 20th century. They are most numerous in Scotland, although reintroduction programs have been successful at establishing breeding pairs in England once more.
All ospreys in the United Kingdom are migratory. The majority of British ospreys migrate south through France, Spain, and across the Mediterranean into Africa. They must then travel across vast expanses of desert over countries like Morocco and Mauritania.
Osprey perched on the post of a fishing pier, looking out for prey
Most American ospreys are migratory, although there are resident populations in the south. Ospreys that breed in the west of the USA fly south through Mexico and Central America but eastern populations often cover long distances over the Atlantic ocean and the Caribbean sea to reach the South American mainland.
Osprey taking off with a recently caught fish
Ospreys typically migrate by day. Occasionally they have to fly overnight when making long-distance ocean crossings because there just aren’t any places to perch and rest.
Studies have shown that ospreys return to the same breeding grounds each year. This site fidelity is not limited to their breeding grounds, however. These birds generally return to their overwintering grounds each year as well.
Ospreys make various stops during their migration to hunt and feed. Interestingly, many ospreys have been observed carrying fish while in flight, indicating that some individuals will feed ‘on the go’. The extent of this behavior is not fully known, however.
Ospreys often spend their first winter on their southern non-breeding grounds. They return to the breeding grounds 18 months after first leaving their nest. Adult birds from migratory populations rarely overwinter in their breeding grounds, however.
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