Ruffed Grouse Population

Establishing Baseline Population Status of Ruffed Grouse and Assessing Response to Forest Stewardship Activities at Hudson Farm, Sussex County, New Jersey-2016-2020

Report Prepared by

  • John Cecil
  • Vice President Stewardship
  • John Parke  
  • Stewardship Project Director – North Region  
  • Kristin Mylecraine, Ph.D., Senior Research Scientist
  • David S. Mizrahi, Vice-President, Research and Monitoring
  • Linda Haan, Director of Corporate and Foundation Relations

The Hudson Farm Club manages 3,800 acres of largely forested habitat in Sussex County, New Jersey.  NJ Audubon has partnered with Hudson Farm Club since 2008 to help develop and guide habitat management practices, and has been conducting bird, amphibian, reptile, and habitat surveys along PSEG’s transmission line corridors and other managed young forest habitat (control sites in close proximity to Hudson Farm) since 2013.  Some of this work includes areas within the Hudson Farm property boundaries.

Habitat management specifically for the Hudson Farm property over the next ten years will follow NJ approved Forest Stewardship Plans (FSP), developed by Gracie and Harrigan Consulting Foresters, as part of a collaborative process with species management recommendations from New Jersey Audubon, Ruffed Grouse Society, National Wild Turkey Federation, NRCS, NJ forest Fire and NJ Fish and Wildlife.  Plan objectives include habitat management to enhance the quality and value of wildlife habitat and improve forest health, while generating income from forest products. In particular, the ultimate goals of the landowner include habitat management for early successional species, habitat improvement for game species, and reestablishment of Ruffed Grouse, either by enhancing habitat to attract grouse from nearby populations, if any, or through other means.       

The Ruffed Grouse (Bonasa umbellis) is a widely-distributed game species found throughout deciduous and mixed forest regions of Canada, the Eastern United States and Rocky Mountain region.  This species relies on early successional forest (Rusch et al. 2000, Desseker et al. 2006), and is most abundant in young forests dominated by aspens and poplars (Rusch et al. 2000). Young forest habitat has declined in New Jersey (Crocker et al. 2008, Crocker 2013, Forest Guild 2014) and throughout the eastern US (Askins 1993, Lorimer 2001, Trani et al. 2001, Brooks 2003, Schlossberg and King 2007), due to the lack of natural and anthropogenic disturbances.  Associated with this reduction in habitat, early successional bird species, as a group, have experienced significant population declines in recent decades (Askins 1993, Dettmers 2003, Schlossberg and King 2007, Sauer et al. 2014). Breeding Bird Survey data suggest that Ruffed Grouse populations have declined by 11% (95% CI: -22.6 to -0.5) between 1966 and 2012 (Sauer et al. 2014). Active management will be required to maintain young forest habitat for Ruffed Grouse and a variety of other early successional bird species of conservation concern.  

Implementation of Hudson Farm’s Forest Stewardship Plans over the next ten years will include regeneration harvests and other management activities to create young forest stands, in order to meet the landowner’s ultimate goal of habitat management for early successional species, habitat improvement for game species, and reestablishment of Ruffed Grouse and other avian species.  Before any proposal for reintroduction and/or translocations can be considered, implementation of Ruffed Grouse occupancy surveys will be needed to determine whether Ruffed Grouse are currently present on the property, and to assess whether planned habitat management activities are achieving the desired response in line with the active management activities. In particular, New Jersey Audubon proposes a Before-After-Control-Impact survey design that will include baseline surveys to determine whether Ruffed Grouse is currently present on the Hudson Farm properties, post-management surveys to assess species response, and surveys at outside control sites to separate response to management activities from overall regional trends.        

Objectives

The overall objective of this project is to implement a Before-After-Control-Impact study to assess habitat management.  Specifically, we propose to (a) conduct pre-management surveys to determine the current status of Ruffed Grouse on the Hudson Farm properties, (b) continue surveys for the first five years of the current Forest Stewardship Plan, and (c) conduct surveys at control sites in northern New Jersey, (sites located in Highlands region and Skylands region of NJ).  At the end of the five year survey period, we will assess the current status of the project and determine if surveys will continue beyond the initial study period.

Proposed Survey Methodology

Survey methods  

Ruffed Grouse drumming surveys will be conducted following modification of published protocols for the species (Jones et al. 2005, Hansen et al. 2010), as well as a survey implemented by NJ Division of Fish and Wildlife on state Wildlife Management Areas in 2009.  Surveys will be conducted at each point location three times between April 1st and May 15th .  Repeated surveys at each point will be conducted at least 5-7 days apart.  Repeated surveys will allow for Occupancy Analyses to account for imperfect detectability and provide an estimate of the proportion of area occupied by Ruffed Grouse (MacKenzie et al. 2006).  All surveys will be conducted between one half hour before and four hours after sunrise, on days with no precipitation and wind speeds less than 12mph.

At each location, observers will conduct a 5-minute point count, recording any Ruffed Grouse observations and listening for drumming activity.  To account for biases in population measures resulting from imperfect detectability, we will incorporate data collection methods designed to accommodate distance sampling (Buckland et al. 2001, 2004).  Observers will record the first minute in which each individual bird was observed, as well as the exact distance to each observation. Exact distance will be measured, when possible, using a laser rangefinder.  For auditory detections, distance will be estimated. Observers will also record observation type (heard, seen, heard and seen, or overflight), as well as basic weather information (wind speed, temperature, sky condition) and time of day.  Observers will also record the exact location (distance and direction) and time of any Ruffed Grouse observations seen or heard while walking between survey points.

Point locations

Survey locations will include existing points along PSEG’s transmission line Right-of-Way that runs through the property, as well as additional mapped points throughout the forested portions of the property (Figure 1).  We will include all existing ROW and control survey locations that are part of an ongoing assessment of habitat management activities along this Right-of-Way, and will add additional survey points along unsurveyed portions of the ROW, following the protocol established in Mylecraine et al. (2015) and maintaining 400m distance from existing points.     

Additional survey points will be located 400m apart throughout the Hudson Farm properties.  Although Ruffed Grouse can be heard up to a maximum distance of 550m (Hansen et al. 2010), other survey protocols, including the Pennsylvania Ruffed Grouse Drumming Survey

(http://www.grousecovers.com/pa-grouse-drumming-survey/) have used 400 yards between survey points.  We used ArcGIS 10.3 to establish points on a 400m grid throughout the property, and removed points that fell within 400m of existing ROW or control points, or 200m of the property boundary or a major road.      

NJ Audubon mapped a total of 55 potential survey points, including:  6 existing ROW points, 2 existing control points, 5 draft points to add along the ROW, and 42 additional draft points throughout the property.  During early spring 2016, these points will be visited to determine accessibility and suitability. A final list of survey points will be determined before the start of the 2016 survey.  

NJ Audubon will establish an equivalent number of survey points at a suitable control site(s) prior to the start of the survey.  Potential control sites include Sparta Mountain Wildlife Management Area and/or Delaware Water Gap National Recreation Area.

As in past years, the NJ Audubon has been working closely with Hudson Farm in regard to forest management projects both on the subject property, as well as throughout the north western NJ region.  In the context of the proposed grouse study, the NJA staff will continue to provide the technical support to assist in the coordination and management of the project site in line with its Forest Stewardship Plan (FSP), as well as, for the surrounding survey control areas (Sparta Mountain, ROWs, etc) so that overall project implementation will be ecologically beneficial at a regional landscape level.  The NJA technical support will include, but is not limited to, continued plan review and recommendations based on any plan modifications and grouse survey monitoring data collection, habitat management unit designation and species management recommendations for both target and non-target species as they pertain to the referenced plans, meeting attendance, conference calls, travel time, actives directly related to public outreach such as NJ Audubon’s field staff to organize, host, and attend public meetings, workshops and presentations, and disseminate information through the web and media as well as continued plan implementation at the Sparta Mountain control area for early successional young forest habitat to provide nesting habitat for ruffed grouse, American woodcock, wild turkey, and golden-winged warbler, etc.  A full report of the data review and collection will be provided at the end of the survey year.