Where Do Ospreys Nest? Platforms, Poles and Treetops

What ospreys look for in a nest site

The osprey needs two things for nesting: plenty of fish nearby and a safe, high spot. Most nests are close to lakes, rivers, reservoirs, estuaries or the coast, usually within a few kilometers of good fishing water.

The ideal site is the top of a tall structure with a flat or forked crown and no branches overhead, so the large bird can fly straight in and out. Height also helps keep eggs and chicks away from ground predators such as raccoons and foxes.

Natural nest sites

Before people changed the landscape, ospreys nested mainly in:

• Dead or broken-topped trees, especially tall conifers standing in or beside water.
• Cliff ledges and rock pinnacles on rocky coasts and islands.
• The ground or low rocks on islands free of mammal predators, for example in parts of the Red Sea, the Gulf of California and some islands off Australia.

In Scotland most ospreys still nest in the flat tops of old Scots pines, while in Scandinavia they use tall pines in forests near lakes.

Nests on human structures

Today a large share of ospreys, especially in North America, nest on things people have built. Common sites include utility poles, channel markers and navigation lights, bridges, cell towers, stadium lights and duck blinds.

These structures are tall, open and often right beside water, so they suit ospreys well. Nests on live power lines can cause fires and power cuts, though, so many utility companies place platforms on top of poles or move nests to new poles nearby, outside the breeding season and in line with wildlife laws.

How nest platforms helped the comeback

Osprey numbers fell sharply in the 1950s to 1970s, mainly because the pesticide DDT made eggshells too thin. When DDT was banned, ospreys began to recover, and nest platforms sped up the process. A platform is usually a sturdy square frame on top of a tall post near water.

Ospreys accept platforms readily, and in many areas of the United States most pairs now nest on them. In New Jersey a design developed by a local conservation group became the state’s official platform plan. Chesapeake Bay, on the US East Coast, now holds one of the densest breeding populations of ospreys anywhere, many of them on channel markers and platforms.

In Britain, platforms built in trees have helped ospreys settle in new areas, for example at Rutland Water in England, where chicks moved from Scotland were released between 1996 and 2001.

How ospreys build and use the nest

Both partners build the nest. The male brings most of the sticks, often breaking dead branches off trees in flight, and the female arranges them. The cup is lined with softer material such as bark, grass, moss and seaweed.

Ospreys also collect odd items: rope, plastic, netting and, dangerously, fishing line and baling twine, which can entangle chicks and adults.

Because a pair adds material every year, old nests can become huge and very heavy. Some nest sites have been used for decades.

Returning to the same nest

Pairs usually stay together for many years but migrate and winter apart. In spring each bird flies back to the shared nest, and whichever bird arrives first starts guarding and repairing it. If one partner does not return, the survivor typically takes a new mate and keeps the same nest. See where do ospreys migrate? for more about these journeys.

Famous osprey nests and webcams

Many people follow ospreys through nest webcams, which run roughly from April to September.

• Loch Garten, Scotland: the RSPB’s nest in Abernethy Forest, where ospreys have nested in most years since 1959, a few years after the species returned to Scotland in 1954.
• Loch of the Lowes, Scotland: a Scottish Wildlife Trust reserve near Dunkeld, once home to a long-lived female known as Lady who bred there for more than 20 years.
• Rutland Water, England: the site of the English reintroduction, where ospreys have bred since 2001.
• Dyfi and Glaslyn, Wales: nests that helped return breeding ospreys to Wales from 2004.
• United States: many state parks, conservation groups and the Cornell Lab of Ornithology host osprey cams, including nests in Montana and on the East Coast.

In Britain ospreys are strictly protected, and it is illegal to disturb a nesting osprey. Many nest locations are kept secret to protect them from egg thieves, so the public sites above are the best places to see them. Watching from a hide or online lets you follow every stage, from eggs to chicks learning to fish, which you can read about in how do ospreys catch fish?