NJ’s Grouse Priority Area Siting Tool (G-PAST)

by Jimmy Sloan, Senior Biologist
Upland Game & Furbearer Research Project
September 2, 2020

Ruffed grouse (Bonasa umbellus) and other species such as American woodcock and golden-winged warbler are highly dependent on young forest habitats, (i.e., forests less than 20 years of age). Although New Jersey is blessed with approximately two million acres of forests, only about 100,000 acres (~5 percent) is in this young forest category. Furthermore, these patches are often located far apart relative to each other and too distant for existing grouse populations to colonize.Most (92 percent) New Jersey grouse occurrences reported to the popular eBird app are located in the state’s northwestern counties. Targeted forestry projects designed to benefit ruffed grouse and other young forest species would have the greatest benefit in this portion of the state.Sawmills were common throughout New Jersey in the mid-19th century and large expanses of woodland were cut. Today, the forest products industry footprint is extremely small, and the benefits of forest management are largely misunderstood by the general populace. The Division conducts forest management practices for wildlife on its properties based on opportunity and human dimensions (see the Habitat Management page).

Grouse Occurrence Sites In Northwest New Jersey Click to enlarge

Photo Courtesy of Gerard W. Beyersbergen Click to enlarge

New information regarding West Nile Virus (WNV) and its negative effect on grouse populations has recently come to light from research by the Pennsylvania Game Commission (PGC). WNV is a mosquito-borne disease most commonly transmitted to birds by the Culex restuans. Population levels of this particular mosquito species decrease as elevation above sea level rises, so the likelihood of WNV transmission decreases at higher elevations. Higher elevations also commonly have greater soil permeability and less standing water due to their slope, so there are fewer breeding areas for all mosquito species.

Armed with this new information, the Division’s Bureau of Wildlife Management and Office of Fish & Wildlife Information Systems, with help from Pennsylvania Game Commission biologist Lisa Williams, developed a Geographic Information System (GIS) based analysis tool to map areas where WNV disease risk is relatively low (i.e., higher elevations, greater soil permeability) and grouse habitat management would yield positive results for existing populations.This interactive tool in grouse management is an adaptive management tool that is always evolving. This model, known as G-PAST, will help in tough decision making for foresters and landowners in directing proper forestry management in areas that will provide quality young forest. Certain unanswered questions still exist, and Division biologists are prioritizing these unanswered questions to enhance future steps in grouse recovery while hopeful that G-PAST will become a multi-state guidance tool.

G-PAST Will Direct Habitat Improvements Where They Will Have the Greatest Benefit Click to enlarge