Bald eagle watchers take note: Another fish-eating raptor is moving in.

Smaller than eagles but still big by bird standards, the osprey is a hawk that feeds almost exclusively on fish and nests near lakes or slow-moving rivers. In September, the state board of game commissioners proposed that the osprey should be removed from Pennsylvania’s listing of birds threatened with endangerment.

“They’ve been doing well for quite a long time and have more than met the criteria to be removed from threatened status,” said Patti Barber, a Game Commission biologist who specializes in endangered birds.

According to standards dictated by the agency’s osprey master plan, the bird has been successfully repopulated, said Ms. Barber. Criteria include at least 50 nesting pairs with at least 10 in each of four watersheds through two consecutive comprehensive surveys.

The number of monitored osprey nest sites in Pennsylvania has risen from 87 in 2010 to 148 in 2016. Allegheny County has done better — monitored sites have held fairly steady with 17 in 2010 and 20 this year.

If removed from the threatened list, the osprey would continue to hold state-protected status under the Pennsylvania Game and Wildlife Code and would have federal protections under the Migratory Bird Treaty Act.

The era of widespread eagle-osprey overlap is new to both species. In pre-Columbian North America, eagles dominated the skies over what would become Pennsylvania. The smaller osprey avoided territories held by the bullying eagles, preferring to nest in the highest tree tops over stillwater lakes and ponds. In the industrial age, the damming of rivers and construction of impoundments has created more ideal osprey habitast, resulting in a somewhat unnatural situation. As populations of eagles and osprey grow, there are more areas where they cohabitate.

“The osprey get pushed to the edges of eagle territories, but there can be an overlap there,” said Ms. Barber.

Bald eagles are bad neighbors, as far as osprey are concerned. Sometimes the bigger birds take over their nests, as occurred at Goddard State Park in Mercer County. A long-held osprey nest directly across the road and a small wetland from the park entrance was overrun more than a decade ago by an eagle couple. Every year since then, they’ve returned and reared offspring.

Where they’re neighbors, eagles sometimes steal the meals of osprey and other hawks. John Oliver, former secretary of the Pennsylvania Department of Conservation and Natural Resources and current mayor of Sewickley Heights, tells the story of watching, just 40 feet overhead, a bald eagle turn on its back in flight, reach up and steal a fish from an osprey’s talons and fly off with it.

In search of high, isolated nesting sites located where trouble can be seen coming from a mile away, osprey have become fond of building nests on the top of power line poles. The nests sometimes ignite, electrocuting the bird and causing power outages.

“In Pennsylvania it’s believed that two-thirds of osprey nests are on top of some human-made structure, often electrical towers and telephone poles,” Ms. Barber said.

To mitigate the problem in Pennsylvania’s northwest and parts of neighboring states, a public-private partnership was formed by Mr. Oliver, state Rep. Parke Wentling, R-Greenville; Goddard State Park manager Bill Wasser; and Audubon Pennsylvania. The coalition was recently awarded a $3,000 conservation grant from energy provider FirstEnergy Corp. to erect 30 creosote-treated wooden poles with platforms on top. The goal is to create high, isolated sites for osprey that are better for nesting than power lines.

The osprey does not appear on federal lists of endangered or threatened species. In Pennsylvania the penalty, or “replacement cost,” for the unlawful killing of a state-threatened species such as the osprey is $5,000. When the Board of Game Commissioners reduces the status from threatened to protected, as expected, the replacement cost would drop to $200. Commissioners agreed that’s not enough. In September they ruled that when the osprey is removed from threatened status, the penalty for killing the bird will be $2,500. A similar process preceded the bald eagle’s removal from the state’s list of threatened species in 2014.

A 30-day public comment period on the osprey’s delisting ends tonight at midnight. Email your comments to osprey@pa.gov.

John Hayes: 412-263-1991, jhayes@post-gazette.com.

First Published: November 12, 2016, 5:00 a.m.