All About Ospreys

Welcome to our osprey nest on the waters of Maryland’s Eastern Shore. As ospreys tend to return to the same nest year after year, we are certain that our two birds are repeat guests. We actually recognize the markings on their heads; if you look closely you may be able to differentiate and then start to “recognize” them as well.

With an average length of 22- 25 inches and an average wingspan of 4.5 – 6 feet, ospreys are one of the largest birds of prey in North America. Females are larger than males, with a slightly larger wingspan. Ospreys have a dark back and wings, with a white breast, belly and head. They also have a distinctive black eye stripe. Juvenile ospreys look similar to adults but have whitish scaling on their back feathers. You will be able to easily differentiate between adults and juveniles as you watch the young ones hatch and grow.

The ospreys’ diet consists almost exclusively of fish, which they catch with their unique barbed talons by diving feet first into the water from as far as 100 feet in the air. For this reason they nest near water sources such as rivers, lakes, ponds and coastal waterways. No wonder they love the Eastern Shore!

Ospreys can be found on every continent except for Antarctica. They are a migratory bird which breed in the North in the summer and head south for the winter. Our birds typically arrive the second week in March, stay for the summer and are gone by the first week in September.

Ospreys build their nests consisting of sticks, sod and grass on the tops of telephone poles, channel makers and similar structures, where they have easy access to fishing. Strategically placed artificial platforms are also popular for attracting nesting pairs, which were endangered after chemical pollutants in the 1950’s thinned eggshells diminishing reproduction. Our ospreys have built their nest using an old wagon wheel, which was put up for them years ago, as a frame. Every year they must clean up and remodel and you will notice that they make additions and changes to the nest in various stages of egg and chick life.

Usually an osprey lays two to three eggs, although quite often one of the eggs never hatches. We have always had three eggs, which have consistently resulted in only two chicks. The third egg always seems to mysteriously disappear soon after the first two eggs hatch. We have never seen what exactly happens to this egg, although everyone has his own theory.

Both parents help to incubate the eggs which will hatch about 4 to 5 weeks after appearing in the nest. The eggs will hatch in the order they were laid giving one chick the older sibling status. Chicks will fledge about 55 days after hatching and will use the nest as home base until they are ready to migrate in early September. North American ospreys migrate to South America, although some may stay in southern states such as California and Florida.

One thing that puzzled us last year while watching the ospreys was that occasionally we would see the adults skim the water as though they were fishing, yet come up empty and fly back to the nest. As it turns out, they were merely getting water on their claws and the feathers directly above their talons and taking it back to the chicks in the nest. During the hot summer months before the young are able to fly and are confined to the nest in the blazing sun, this skimming method by the parents is how water is delivered to the nest. Apparently ospreys cannot live on fish alone.