In the series of public meetings on the bear population that the DEP had held around the State, citizens raised concerns about the adequacy and soundness of the population estimates. The independent review panel was designed to open the process to review by interested groups and ensure thoughtful deliberation of both data/modeling and appropriate management practices.
The members of the independent bear panel were: Louis Berchielli, biologist, New York Department of Environmental Conservation; George Howard, biologist, New Jersey Fish and Game Council; Dr. Lynn Rogers, biologist, Wildlife Research Institute - Minnesota; Dr. Allen Rutberg, biologist, Tufts University; Harry Spiker, biologist, Maryland Department of Natural Resources; Lynda Smith, Bear Citizen Group. Dante DiPirro, Counselor and Legal Policy Advisor to the Commissioner, New Jersey Department of Environmental Protection, chaired the panel on behalf of the Commissioner; his function was to preside over the panel and facilitate its work.
Three independent statistical experts-- Dr. Michael Conroy of the University of Georgia, Dr. Gary White of Colorado State University and Dr. Edwin Green of Rutgers University-- assisted the panel. They reviewed the data and modeling and provided their comments to the panelists.
This report and the recommendations contained in it represent the conscientious efforts of all the members of the panel and the statistical experts. The panel has been able to reach a consensus on a number of issues that are set forth in the first section of this report. The panel felt that it was important to attempt to reach consensus whenever possible to assist public debate on bear issues. Each panelist has been given the opportunity to include his or her own personal comments in the final section of the report.
SUMMARY OF FINDINGS AND RECOMMENDATIONS OF THE PANEL
The Division of Fish and Wildlife recently projected a population of 3278 adult black bears in New Jersey. With the assistance of the consulting statistical experts, the panel reviewed the Division’s study.
The panel was not able to reach a consensus on whether the Division of Fish and Wildlife’s population estimate could be relied upon. Some panelists felt the estimate was reasonable. Others had concerns with the approach and assumptions that were too significant to accept the estimate without further inquiry. The consulting statistical experts also split on the issue of the population estimate’s reliability.
The panel did agree that Fish and Wildlife staff has collected a good amount of data, handled and examined numerous bears, collected hair samples as part of monitoring and outfitted and tracked a good number of bears with radio collars.
The panel further agreed that further modeling and data collection is appropriate. Revised modeling should, at a minimum, address the following issues:
• assumptions used to expand population estimates;
• estimation of the area of influence around each hair snare;
• assumption of uniformity over the prime bear range;
• establishment of appropriate confidence interval;
• evaluation of baiting and whether it skews sampling by attracting bears into what is otherwise not their range;
• model selection evaluation of whether modeling selection results in an over or under estimation of population;
• data collection re: birth rate, death rate, age, gender, distribution, home range and movement;
• possible selection of several discrete areas (varying and representative) where rigorous sampling would be done; and
• establishment and analysis of population growth rate.
The panel would like to see these issues addressed in the next round of the Division’s modeling. By addressing and building in these factors, this process should be able to arrive at population estimates and trend data that can be widely accepted.
In the meantime, the panel determined that it would be helpful if it could reach a consensus on a potential range in population, even if all that could be offered would be an estimate. To do so, the panel did not rely upon the Fish and Wildlife estimate. In order to arrive at a conservative estimate, the panel: started with the estimate of New Jersey field researcher, Patty McConnell, of 550 adult black bear in 1992; picked what it believed was a conservative estimated growth rate of 8.5% per year (reproductive rate less mortality rate); then multiplied this growth rate out each year through 2003; this calculation yielded a conservative estimate of approximately 1350 adult black bear through 2003.
There was no consensus that the 8.5 percent figure was in fact the correct number. Some panelists felt the number was low. Others noted that the number was not arrived at scientifically but was selected by the panelists in order to be able to present what was likely a conservative estimate. It was further noted that if the growth rate were in reality double that used, (i.e. 17%), the population estimate would exceed 3,000. The panel felt that providing this information, with the caveats stated herein, would at least provide some assistance to the public.
It appears to the panel that the number of bears in the State has increased, though it is not possible for the panel to evaluate what the growth trend is or determine if the increase is statistically significant. We will be attempting to determine this as the State goes forward with enhanced modeling over the next year.
The panel was able to reach consensus on the importance of bear management activities such as public education, aversive conditioning, response to nuisance complaints, enforcement of the prohibition on feeding bears, proper securing of garbage, cooperation between local, municipal and State enforcement officers and the need to change public attitudes towards bears and the bear population. More on these topics is contained in the comments of individual panelists at the conclusion of this report.
The panel believes that it can contribute to the process going forward and is willing to continue to serve if the Commissioner determines that it would be helpful. In this regard, the panel could work with Fish and Wildlife concerning modeling, data collection, review of modeling results, review of existing and potential management practices and any other bear-related issues. Posted by: Staff at rt23.com
Website: NJ Division of Fish & Wildlife
March 06, 2003
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