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 ManagementDr. 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 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
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.
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.
Effects
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 PennsylvaniaMark 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.