Flying high above only to dive at terminal speed and take fish from the water’s surface, a bird familiar to many of us can be seen all around Gaston and Kerr Lakes. This week we will talk about the Osprey, a bird commonly seen soaring over shorelines or standing in huge stick nests.
Despite what many may think, the Osprey is actually a large species of hawk with long, narrow wings, a brown upper body, white underside, and distinct white face with brown bands over the eyes. Many actually confuse them in flight with Bald Eagles, but Osprey have a distinct kink in their wings, resembling the letter “M” when seen from below. Osprey typically weigh between 3 and 5 pounds with a wingspan of 5 to 6 feet! Osprey are not home bodies either, often migrating more than 150,000 miles during their 20+ year lifespan to breed.
Osprey are rather unique in that they seek out live fish as their primary prey. Although they can only dive to about 3 feet, they are extremely efficient predators catching fish at least one of every four dives and sometimes as many as every three. They exert little energy spending as little as 12 minutes hunting each time. One reason for their efficiency is a reversible outer toe that allows them to grab with four toes: two in front and two behind.
Osprey are rather solitary birds that typically roost alone or in a small flock. Osprey are quick to defend their nests from other osprey, often chasing away any intruders. Many of you have undoubtedly noticed Osprey hovering over nests repeatedly screaming calls and descending frequently. This is most likely a male putting on a display during breeding season.
Osprey often prefer man-made structures on which to build its massive nests such as ducks blinds, telephone poles and nesting poles. The male usually finds most of the nesting material and the female does the job of arranging the “home”. Pairs typically stay together and build upon their “home” for many years. A new nest often starts at less than 3 feet in diameter and only a few inches deep. However, after years of building on, a pair can develop a nest nearly 10-15 feet deep and 6 feet in diameter! Unlike some other birds, Osprey eggs do not hatch all at once as the first chick can sometime emerge nearly a week before the last.
Like the bald eagle, the Osprey are a major success story aided by bans of DDT use. Although numbers crashed in the 1950s, they have steadily increased in recent years. There are however, still a few threats to Osprey in present day. More recently, Osprey have been found entangled in discarded trash including fishing line and twine. The birds often take these materials back to their nests where they and their young can become entangled and consequently die. Please remember this the next time you think to toss that backlashed fishing line into the lake or throw old weedeater twine down the bank.
For more information on Osprey, visit the National Audubon Society or NC Wildlife links posted in “web links for additional information”. This week’s topic was included by popular demand from the reader. Please feel free to send in your own suggestions for next week’s topic!
*Photo by Jeff Lewis in Manteo, NC
If you have questions please contact your Aquatic Extension Associate, Brett M. Hartis, at (919)-515-5648 or email at email@example.com.