PENNSYLVANIA (WHTM) — More than half of the Pennsylvania Game Commission’s state-listed endangered and threatened species in Pennsylvania are birds. Four bird species are threatened and 16 are endangered in the state. Most of these species have been on the list since it was created in the 1970s.

Experts are taking steps to protect these endangered and threatened birds. “Our focus is trying to maintain the habitat that supports these birds and then minimize the negative interactions between people and the birds,” Patti Barber, an endangered bird specialist with the Pennsylvania Game Commission said.

The state’s Game Commission, along with other state and federal authorities, works to ensure that development does not interfere with protected species’ habitats. Barber explains that the Game Commission also takes steps like encouraging individuals to avoid certain activities while the birds are nesting and rearing young.

The largest group of Pennsylvania’s endangered birds lives in marshes, says Barber, and another significant portion of them resides in grasslands. Both of these types of habitats have been disappearing in Pennsylvania.

The U.S. Fish and Wildlife Service estimates that more than half of the state’s wetlands were lost from the 1780s to the 1980s. Pennsylvania-based naturalist writer Marcia Bonta notes in a 2006 article that 150,000 acres of meadows and grasslands existed here before Europeans arrived, and only about 350 acres are left.

Human activities like agriculture, development, and even re-forestation — something that seems beneficial from an environmental standpoint, but is actually a bit of a double-edged sword — have all contributed to the loss of these habitats.

“We’re trying to squeeze more and more people as well as more and more critters into less available space,” Barber said. “A big part of what we do is trying to maintain the habitat that supports [endangered bird species] in a way that the birds can still take advantage of it.”

And Barber’s mission is not just to protect the species overall, but to protect them here in Pennsylvania. In fact, state-listed endangered and threatened species may be different from federally listed species because the Pennsylvania list reflects struggling populations specifically in Pennsylvania.

A species may be populous in the United States as a whole, but if its population is declining in Pennsylvania, the state works to protect it locally. Barber wants people to be able to see these birds in this state, rather than having to travel somewhere else in the county to see them.

And the presence of numerous bird species helps maintain the resiliency of ecosystems, explains Barber. The loss of a species can have a ripple effect on an ecosystem. Healthy communities may be able to survive the loss of a species or two, “but as they start losing more and more species, they become more and more susceptible to that collapse,” Barber said.

When people commit to protecting a species, their conservation efforts can pay off. Bald eagles and ospreys are two bird species that are recovered, meaning they were previously listed as threatened or endangered in the state, but their numbers have rebounded and they are no longer at risk of extinction here.

The steps taken to protect species like the bald eagle have also had benefits for humans, Barber says, which likely contributed to the birds’ successful recovery. These steps included things like cleaning up waterways so humans would have safe drinking water, which led to better water quality where eagles were foraging, so fish stocks improved, and the birds had more to eat.

“The reason that the species that are coming back did is because the human community — meaning you and I and all of our grandparents — they saw the value in both the birds themselves, but also…clean water, clean air, minimal use of pesticides, and all of those things that set the stage for the recovery of those examples,” Barber said.

“If as a community, we felt the same way about these other birds, we’ve already proven we can succeed,” Barber said.