The Pennsylvania Audubon Society has designated all 13,050 acres (5,280 ha) of Ricketts Glen State Park a Pennsylvania Important Bird Area (IBA); an IBA is  defined as a globally important habitat for the conservation of bird populations.
The state park was originally part of the much larger North Mountain IBA, which encompassed 114,978 acres (46,530 ha), including all of the park and nearby Pennsylvania State Game Lands Numbers 13, 57, and 66.
Ricketts Glen State Park is featured in the Audubon Society's Susquehanna River Birding and Wildlife Trail Guide.

Ornithologists and bird watchers have recorded a total of 75 species at Ricketts Glen State Park and within the North Mountain IBA.
Several factors contribute to the high total of bird species observed: there is a large area of forest in the park, as well as great habitat diversity.
The location along the Allegheny Front also contributes to the diverse bird populations.
The North Mountain IBA was said to be the "largest extant forest" in northeastern Pennsylvania and one of the largest forests in the state of Pennsylvania.
It was officially adopted by the North Branch Bird Club and was "well-known" by members of local Audubon societies and the Pennsylvania Society for Ornithology.

Ricketts Glen State Park provides a breeding habitat for four species of flycatchers and two species of waterthrushes.
American bittern nest near the park.
Bald eagle are frequent visitors to the park, and some ornithologists believe they may be nesting there since adult pairs have been observed with their young.
The park is a nesting location for three "rare" birds, including two birds of prey (the northern goshawk and northern harrier), and Swainson's thrush, as well as one "at risk" duck, the green-winged teal.

Ricketts Glen State Park has extensive acreage of "interior forest" that is far from open space; several bird species that are area-sensitive are found within these forests in the park, including the black-throated green warbler, red-eyed vireo, dark-eyed junco and black-capped chickadee.
Two species of owl, barred and northern saw-whet, inhabit the deep forests.
The hemlock forests of the glens are home to the Louisiana waterthrush, Acadian flycatcher, Blackburnian warbler, blue-headed vireo, magnolia warbler, brown creeper, golden-crowned kinglet and winter wren.
Wood thrush are found in the lower elevations of the park and are replaced within the ecosystem by hermit thrush at the higher elevations.
The Canada warbler and black-throated blue warbler are on several watchlists, but are common within the park.
The Canada warbler inhabits blueberry thickets with white-throated sparrow, while the black-throated blue warbler is found in the forests atop the plateau with the least flycatcher.
Common raven are regularly seen soaring over the forests of the park looking for carrion.
Canada goose are present in the park and have been classified as a "pest" due to their high numbers and the large amount of fecal waste they leave on the shores of Lake Jean.
Ricketts Glen's forests also support populations of  Nashville and yellow-rumped warblers, yellow-bellied sapsucker, red-breasted nuthatch, and purple finch.
The Pennsylvania Audubon Society has designated all 13,050 acres (5,280 ha) of Ricketts Glen State Park a Pennsylvania Important Bird Area (IBA); an IBA is  defined as a globally important habitat for the conservation of bird populations. The state park was originally part of the much larger North Mountain IBA, which encompassed 114,978 acres (46,530 ha), including all of the park and nearby Pennsylvania State Game Lands Numbers 13, 57, and 66. Ricketts Glen State Park is featured in the Audubon Society's Susquehanna River Birding and Wildlife Trail Guide.
Ornithologists and bird watchers have recorded a total of 75 species at Ricketts Glen State Park and within the North Mountain IBA. Several factors contribute to the high total of bird species observed: there is a large area of forest in the park, as well as great habitat diversity. The location along the Allegheny Front also contributes to the diverse bird populations. The North Mountain IBA was said to be the "largest extant forest" in northeastern Pennsylvania and one of the largest forests in the state of Pennsylvania. It was officially adopted by the North Branch Bird Club and was "well-known" by members of local Audubon societies and the Pennsylvania Society for Ornithology.
Ricketts Glen State Park provides a breeding habitat for four species of flycatchers and two species of waterthrushes. American bittern nest near the park. Bald eagle are frequent visitors to the park, and some ornithologists believe they may be nesting there since adult pairs have been observed with their young. The park is a nesting location for three "rare" birds, including two birds of prey (the northern goshawk and northern harrier), and Swainson's thrush, as well as one "at risk" duck, the green-winged teal.
Ricketts Glen State Park has extensive acreage of "interior forest" that is far from open space; several bird species that are area-sensitive are found within these forests in the park, including the black-throated green warbler, red-eyed vireo, dark-eyed junco and black-capped chickadee. Two species of owl, barred and northern saw-whet, inhabit the deep forests. The hemlock forests of the glens are home to the Louisiana waterthrush, Acadian flycatcher, Blackburnian warbler, blue-headed vireo, magnolia warbler, brown creeper, golden-crowned kinglet and winter wren. Wood thrush are found in the lower elevations of the park and are replaced within the ecosystem by hermit thrush at the higher elevations. The Canada warbler and black-throated blue warbler are on several watchlists, but are common within the park. The Canada warbler inhabits blueberry thickets with white-throated sparrow, while the black-throated blue warbler is found in the forests atop the plateau with the least flycatcher. Common raven are regularly seen soaring over the forests of the park looking for carrion. Canada goose are present in the park and have been classified as a "pest" due to their high numbers and the large amount of fecal waste they leave on the shores of Lake Jean. Ricketts Glen's forests also support populations of  Nashville and yellow-rumped warblers, yellow-bellied sapsucker, red-breasted nuthatch, and purple finch.
Ricketts Glen State Park