The osprey was never a common nesting species in Pennsylvania. But in 1982 state wildlife biologists were alarmed when they noted a total absence of breeding pairs.
Thirty-five years later, following a national ban on harsh agricultural pesticides and a successful state reintroduction program, the fish-eating “river hawk” is back in abundance. Having satisfied the conservation goals of a 2015-2025 statewide osprey management plan, the big raptor has been removed from Pennsylvania’s list of threatened species. It is now considered “protected.”
They’re sometimes mistaken for bald eagles, which can stretch their wings up to 7½ feet. Adult osprey have a wingspan of 6 feet and their black or brown and white plumage is patterned differently. A slim body and kink in the wings give osprey a distinctive M shape when viewed from below.
Osprey are unique among North American raptors for exclusively eating live fish and diving feet first into water — from great heights at high speed — to catch them. With a reversible outer toe, osprey talons grasp fish from the front and back, aided by barbed pads on their feet. Efficient anglers, it takes osprey an average of just 12 minutes to find fish, and they are successful on 70 percent of their dives.
Pennsylvania is at the extreme southern edge of the osprey breeding range, but some resident birds stay in the state year-round. Most breed at Canadian latitudes and winter in South America, migrating some 160,000 miles in a 15- to 20-year lifetime. The osprey is not a game species managed for hunting, but all migrating birds are protected under the international Migratory Bird Treaty Act. Osprey are not federally listed as endangered or threatened.
According to a state Game Commission statement, survey data showed the bird met established criteria for removal from threatened status. To assure that a self-sustaining osprey population can survive natural population cycles and unexpected events, the management plan requires “a minimum of 50 nesting pairs, distributed across at least four watersheds, each containing a minimum of 10 pairs for two consecutive statewide surveys.”
When the osprey was a threatened species, the fine for killing the raptor in Pennsylvania was $5,000. The standard “replacement cost” for the unlawful killing of a protected species is $200. However, game commissioners decided that the creation of a robust osprey population warranted a greater deterrent, so they have set the penalty at $2,500. The agency will continue to monitor osprey nests to ensure continued population growth.
John Hayes: 412-263-1991, jhayes@post-gazette.com.
First Published: February 11, 2017, 5:00 a.m.