Osprey Nesting at Barr Lake State Park

BRIGHTON, CO. – Barr Lake State Park may have an osprey nest. In November of 2010, Jacob Nelson of Brighton designed and installed two osprey nesting poles at the northeast end of Barr Lake. The nesting poles were Jacob’s Eagle Scout Project, which is one of the requirements for earning the rank of Eagle Scout in the Boy Scouts of America. United Power had donated the poles and provided installation equipment and assistance.

The project may have succeeded this spring. An osprey was observed on one of the nesting platforms on April 29, and the bird appeared to be making a nest.

The male osprey selects the nesting site, ideally located near a good supply of food, provides safety from predators and is in an open area. Nesting sites are usually tall, dead trees or man-made structures, such as the power poles at Barr Lake. A female will join the male at the nesting site and breeding of migratory ospreys usually begins during April or May.

During courtship, the male performs aerial acrobatics and presents the female with food or nesting material, accompanied by a courtship call. The male will feed the female even before she lays eggs and often throughout the rest of the breeding season, while the female stays in the nest to look after the young and fend off predators. How well the male feeds the female determines the strength of the pair bond.

The nest, a platform of sticks, leaves and other material, is reused every season. Both parents build or refurbish the nest. Two to four, usually three, eggs with reddish-brown spots are laid. But there is sibling rivalry among the young. So it is rare for more than one or two to survive.

The female does most of the incubation, but relies on the male to feed her during the five to six week incubation period. The young fledge in about six weeks. Ospreys are able to breed at 3-5 years old and can live for 13-18 years.

Read DesertUSA’s page on birds of the southwest here.

Source: Colorado State Parks