Ongoing Wildlife Research Projects

 

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Long-term Study of Ruffed Grouse Population Response to Habitat Management - Diefenbach and Palmer

Denning Ecology of Black Bears in Pennsylvania - Ternent and Diefenbach

Hunter Distribution and Harvest Rates of Female White-tailed Deer in Pennsylvania - Keenan and Diefenbach

Effects of the Conservation Reserve Enhancement Program on Eastern Cottontail (Sylvilagus floridanus) Populations in Pennsylvania - Fritsky and Diefenbach

Use of Reclaimed Surface Mines by Grassland Birds: Identifying Strategies to Conserve and Manage Grassland Landscapes for Viable Songbird Populations - Mattice and Diefenbach

Effects of Antler Restrictions on Yearling Buck Survival, Buck Harvests, and Hunter Satisfaction in Pennsylvania - Wallingford and Diefenbach

 

 

Long-term Study of Ruffed Grouse Population Response to Habitat Management

    Dr. Duane R. Diefenbach, Pennsylvania Cooperative Fish & Wildlife Research Unit

    Mr. William L. Palmer, Cooperator, Pennsylvania Game Commission

 

The purpose of this study is to document how grouse populations respond to intensive forest management.  The study is located on State Game Lands No. 176 in Centre County, Pennsylvania.  The study area includes an extensively managed control area of 1,440 acres (no patch cutting), and an intensively managed area of 1,360 acres with 2.5-acre patch cuts on a 4-period rotation.  Patch cutting occurred in 1976-77, 1981-82, 1985-88.  The final cuttings in the 4-period rotation are being cut in 1999-2000.

Grouse populations are monitored by recording flushes along permanent transects in the fall and spring, and drumming surveys during the breeding season.   The area has been closed to hunting since the conclusion of the 1988-89 season.

Results to date suggest the number of activity centers of drumming males peak about 14 years following timber harvest.  Fall flushes per mile have been 0.1 to 0.7 greater on the treated area (since the area was closed to hunting).  We plan to recommend to keep the area closed to hunting at least 15 years following the last cutting rotation.

Click here to view annual reports:  1998   2002  

Click here for 23-year report (7,450 KB):  Ruffed Grouse Responses to Management of Mixed Oak and Aspen Communities in Central Pennsylvania

 

Hunter distribution and harvest rates of female white-tailed deer in Pennsylvania

 

 Matthew T. Keenan, Graduate Research Assistant

 Dr. Duane R. Diefenbach, Advisor

 

 

In cooperation with the Pennsylvania Game Commission, this study is being conducted to estimate the harvest rate of female white-tailed deer on two study areas located in Sproul State Forest and Tuscarora State Forest .  As many as 77 deer per year will be captured on each study site in 2005 and 2006.  In addition, at each location, 7 deer will be fitted with GPS collars and the remainder with radio-collars.  Each animal will be located via ground telemetry at least two times per week.  With regular monitoring, both prior to and during the hunting season, an accurate estimate of the location and cause of mortality (harvest and non-harvest) of all collared deer will be obtained.  Ground telemetry will also provide information on habitat use and estimates of doe dispersal rates.

 

A secondary objective of the study is to explore the relationship between hunter density and doe harvest rate.  Aerial surveys will be conducted during the hunting season to estimate hunter density and distribution on both study sites.  We will use data on hunter density and distribution to explore what factors increase the risk to harvest of individual deer.

 

Effects of the Conservation Reserve Enhancement Program on Eastern Cottontail (Sylvilagus floridanus) Populations in Pennsylvania

 

Richard Fritsky, Graduate Research Assistant

Dr. Duane R. Diefenbach, Advisor

Robert C. Boyd, Scott Klinger, Tom Hardisky, Cooperators, Pennsylvania Game Commission

 

 

 

The purpose of this study is to assess how USDA's Conservation Reserve Enhancement Program (CREP) affects eastern cottontail populations in Pennsylvania.  CREP is a federal-state conservation program designed to address natural resource problems related to agriculture.  Through CREP, farmers and landowners receive financial incentives to enroll voluntarily in the Conservation Reserve Program (CRP) and to stop agricultural production on marginal lands.  The primary objective of CREP is to conserve highly erodible soils and to improve water quality and wildlife habitat.  In order for CREP to benefit cottontail populations it must increase their survival or productivity, and increase the cottontail carrying capacity of the landscape.  These increases should result in an observable increase in cottontail abundance unless there is also large increases in emigration or predation.

 

The evaluation process begins by determining if cottontails use CREP habitat and if so, how much it is being used relative to other habitat types.  This relationship between the amount of CREP on a landscape and cottontail habitat use will be quantified using location data obtained with radio-telemetry.  The final step in evaluating CREP will be to make recommendations for improving its effectiveness as cottontail habitat.  Types of recommendations that are possible from the habitat use, survival, productivity, and abundance estimates include:  (1) types of vegetation to plant to achieve maximum increases in rabbit populations and (2) amount of CREP needed to maximize cottontail density.  With the information obtained from this study, wildlife managers will be able to predict how abundance will change as CREP is added to new areas.

 

 

 

Use of Reclaimed Surface Mines by Grassland Birds: Identifying Strategies to Conserve and Manage Grassland Landscapes for Viable Songbird Populations

 

 

Jennifer A. Mattice, Graduate Research Assistant
Dr. Duane R. Diefenbach
, Advisor
Daniel W. Brauning, Cooperator, Pennsylvania Game Commission

Recent surveys (1998-99) on reclaimed surface mines in western Pennsylvania have estimated densities of Henslow’s Sparrows ranged from 0.65 singing males/ha (95% CI = 0.57 - 0.74) on high quality reclaimed mine areas to 0.10 singing males/ha (95% CI = 0.08 - 0.16) on lesser quality reclaimed habitats (D. W. Brauning and D. R. Diefenbach, unpublished data).  Abundance of grassland songbirds seems to be related to age of reclaimed areas, which is related to vegetation succession, the technology used reclaim surface mines, and the size of reclaimed areas. Consequently, the objectives of this proposed research are to quantify the following:

1. Estimate density and abundance of grassland songbirds in western Pennsylvania on reclaimed surface mines,

2. Determine the relationship between age and size of reclaimed mines and abundance of grassland songbirds,

3. Determine how the spatial juxtaposition of reclaimed surface mines affect the presence and/or abundance of grassland songbirds.

This research will quantify the characteristics of reclaimed surface mines that are related to the abundance of grassland songbirds. This information will help managers identify reclaimed sites likely to have abundant grassland songbird populations, which would be valuable in aiding decisions of whether to manage reclaimed sites as grassland habitat. Specific products provided by this research will be the following:

1. A GIS map of existing reclaimed surface mine habitat in nine counties in western Pennsylvania, which would spatially link the location, size, age, habitat condition (e.g., grassland, grassland with shrub invasion, etc.) of reclaimed surface mines with abundance of Henslow’s Sparrows, Grasshopper Sparrows, and Savannah Sparrows,

2. A quantitative model of the relationship between size, age and habitat condition of reclaimed surface mines to the abundance of Henslow’s Sparrows, Grasshopper Sparrows, and Savannah Sparrows, and

3. A quantitative model that explicitly links the spatial juxtaposition of reclaimed surface mine habitats to the abundance of Henslow’s Sparrows, Grasshopper Sparrows, and Savannah Sparrows.

Additional information

Diefenbach, D. R., J. T. McQuaide, and J. A. Mattice. 2002. Using PDAs to collect geo-referenced data. Bulletin of the Ecological Society of America 83:256-259.

Diefenbach, D. R., D. M. Brauning, and J. A. Mattice. 2003. Effects of observer variability and species detection on estimates of abundance of grassland songbirds. Auk 120:1168-1179.

Mattice, J. A., D. W. Brauning, and D. R. Diefenbach.  In Press.  Abundance of grassland sparrows on reclaimed surface mines in western Pennnsylvania. Pages xxx-xxx in C. J. Ralph and T. D. Rich, editors. Pacific Southwest Research Station, USDA Forest Service General Technical Report.

 

 

New Deer ResearchEffects of Antler Restrictions on Yearling Buck Survival, Buck Harvests, and Hunter Satisfaction in Pennsylvania

  Bret D. Wallingford, Graduate Research Assistant 

  Dr. Duane R. Diefenbach, Advisor

 

Antler restrictions are a deer management tool that regulates the legal harvest of antlered deer to those with a minimum number of points on one antler.  Antler restriction regulations can be used to manipulate the sex ratio and harvest rate of antlered deer.  Whereas antler restrictions have been tried in other states, no research has documented their effects on harvest rates of yearling bucks.  The purpose of this research is to implement a 3- or 4- points/side antler restriction regulation, in different areas of Pennsylvania, and then measure survival of protected antlered deer, changes in the antlered deer harvest, and level of hunter satisfaction.  Centre and Armstrong counties will be used for the 3- and 4-point study areas, respectively.  For each of three years, 100 male fawns will be caught on each area in winter using drop-nets, dart guns, Clover traps, and helicopters and marked with ear tag radiotransmitters or radiocollars.  Survival of each cohort of marked deer will be monitored through two subsequent hunting seasons.  Harvests will be measured using the reported deer harvest from hunters and estimates of reporting rates from hunters known to be successful.  Hunter attitudes will be evaluated using mail surveys. 

 

More details at the Pennsylvania Game Commission website here

 

Denning Ecology of Black Bears in Pennsylvania

  Mark C. Ternent, Co-Investigator, Pennsylvania Game Commission

  Duane R. Diefenbach, Co-Investigator

 

 

The Pennsylvania Game Commission estimates the population size of black bears by capturing and tagging bears March-October and then determining the number killed by hunters and the number of tagged bears recovered in the harvest.  Recent analyses of population estimates for black bears in Pennsylvania (Diefenbach et al., In Review) indicate that the accuracy and precision of these estimates is affected by the proportion of females denned during the hunting season.  The proportion of females denned varies considerably among hunting seasons depending on the reproductive status of bears (pregnant or with cubs), food availability, and possibly weather.  The purpose of this study is to obtain more information on factors influencing denning and using that information to improve the precision and accuracy of population estimates.