Wildlife Watching – Osprey

Description:

• A large raptor with a distinctive M-shaped flight silhouette, created by a unique kink in the wings).
• Individuals have white plumage with dark brown back, prominent dark eye streak, dark wrist patches and on females, a “necklace” of dark streaks on the breast.
• Wingspan is 147-183cm.

Habitat:

• Riparian areas such as shorelines or forest edges adjacent to water.
• Ospreys build large stick nests in tall trees, snags or manmade structures such as utility poles, bridge posts, pilings and nest platforms near water.

Behaviour:

• Osprey communicate with high-pitched whistling chirps. Alarm calls are a rapidly increasing set of shrill chirps.
• Osprey tend to mate for life and often return to the same nest site every year. The female lays three eggs and does all of the incubation, while the male does all of the fishing to feed the female and the young once they hatch.
• Osprey hunt by flying over shallow water, looking for fish. Once they spot a fish, they will hover briefly in the air before folding their wings and dropping into a fast dive, feet first. They splash into the water, disappearing completely, before emerging with a fish gripped in their talons.
• Ospreys mate for life but spend the winters apart. Females leave British Columbia first in the late summer, leaving males and juveniles behind. They will migrate up to a month later.
• They migrate individually and spend the winter in different wintering grounds. Amazingly, the pairs return to the nest within a week of each other in the spring. (The males arrive first.)
• Juveniles will spend 18 months in wintering grounds after their first migration before returning to BC to breed.
• Typically they live 7-10 years, but can live up to 25.

Diet:

• Ospreys are piscivores, eating almost exclusively fish.
• They may also eat the occasional rodent or bird.

Connections:

• Osprey populations were nearly wiped out by DDT use between the 1950s and 70s. The pesticide caused thinning of eggshells, which reduced reproductive success. Thankfully osprey have made a remarkable recovery.
• Osprey nest webcams are popular among many birdwatchers. FortisBC manages a webcam at a nest in the nearby city of Kelowna.

Cool Facts:

• Osprey feet are uniquely adapted to catching fish. Unlike other birds of prey that have three forward-facing toes and one hind toe, the osprey can swing its outer toe to the back to help them carry fish parallel to their bodies in flight. Sharp spicules on the bottoms of their feet also aid in gripping slippery fish.
• Osprey are the most widely distributed bird of prey and can be found on every continent except Antarctica.
• Osprey nests are huge! They typically measure about 1-1.5m across and 0.5m deep, but as they add to the structure year after year, they can reach depths of 3m.