ed tavss 2010 bear study

8/8/2019 Ed Tavss 2010 Bear Study

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AN INVESTIGATION INTO THE REPORTED SURGE OF SERIOUS BEAR INCIDENTS IN NEW JERS

Edward A. Tavss, PhDDepartment of Chemistry and Chemical Biology

Rutgers University


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DRAFT

SYNOPSIS

Commissioner Bob Martin, in his approval of the New Jersey Fish and Game Councils 2010 Comprehensive BlPolicy, said, Growth [in the black bear population] coincides with an increase in serious bear incidents supporticontrol [i.e., a hunt] . . . This statement is the crux of the issue. The Department of Environmental ProtectionWildlife (F&W) and the New Jersey Fish and Game Council (Council) have led many to believe that there has b

of serious bear incidents per year. But is this true? Has there been an increase in serious bear incidents per year

A change in the number of serious bear incidents (Category I and II complaints) per year can only be determinedthe collection and interpretation of bear incidents over at least several years, under the same conditions each yeaconditions were notthe same. They varied markedly in the number of

sources used for collecting and interpreting the data inclusion of duplicate records miscategorizations of type inclusion of faxed police department (PD) reports

When adjustments were made by the author to correct these errors, linear regression analyses of the resulting dat

1999 to 2009 there was actually a statistically significant decrease in complaints, not an increase.


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PROCEDURES AND METHODOLOGY

YEARS CHOSEN FOR THE ANALYSISComplaint records were obtained for 2007 and 2009. 2007 was chosen because it was the last year of decreasinCategory I and II complaints). Either 2008 or 2009 could have been chosen, representing the years of the reportand 1803 complaints, respectively), but 2009 was chosen to bring the analysis to the present. Time and financiaother years prohibitive. All of the data from 2007 and 2009 were entered onto a spreadsheet. Every parameter oanalyzed to try to get an understanding of the differences between 2007 and 2009.

TWO CATEGORIES OF PD COMPLAINT RECORDSThe PD complaint records are divided into two types. One is the bulkPD complaint reports, referred to as Poliline graph of Figure 2 in the Councils report.1 The other is the police department complaint reports which werecategorized and numbered by F&W, and subsequently became part of the F&W complaint records. It is these incomplaint records that are discussed in this report (referred to as faxed PD records), not the bulk PD complain

CATEGORY OF BEARS CHOSEN FOR THE ANALYSISCategory I, II and III bears are defined in the Council report as follows (1). Category I black bears are those bearan immediate threat to human safety or that causes agricultural damage to farmland as defined pursuant to the Fa(N.J.S.A. 54:4-23.1 et seq.) or significant damage (>=$ 500) to property. Category II black bears are nuisance b

life or property. Category III bears are bears that are exhibiting normal behavior and are not creating a threat to are a nuisance. The Council report focuses only on Category I and II bears, the bears that reportedly cause serioreport also will focus only on Category I and II bears, and ignore all data on Category III bears. Although Categwith humans have been referred to as serious bear incidents, this report will refer to these interactions simply a


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Figure 12: As stated above, there were miscategorizations of type. Since the majority of miscategorizations waCC reporting was exclusively in 2009, it is not surprising that there would be many more complaint report miscamiscategorizations) as compared to 2007 (231 miscategorizations).

Figure 13: As discussed above, there were major errors in the states report regarding the number of serious becompared to 2009. The main problem was the collection of bear complaint data from three different sources (F&compared to virtually a single source (F&W) in 2007. In addition, large differences were found in complaint recmiscategorization of type, and the number of faxed police department records. An effort was made to repair F

all duplications, miscategorizations and police department records from the 2007 and 2009 complaint records. Tserious bear incidents decreasing from 1999 to 2009 (significant at the 96% confidence level). It should be pointhe 95% confidence level is the requirement for most scientific studies. Significance at the 90% confidence levebiological studies, due to inherent lack of reproducibility of biological data.

Figure 14: Rather than making multiple corrections to repair the data, as in Figure 13, one might simply delete aCenter records from the 2009 analysis. The results continue to demonstrate a statistically significant decrease in1999 to 2009 (significant at the 99.8% confidence level)

Figure 15: . Yet another approach to evaluating the data is to simply acknowledge that the experimental proceduand 2008, so only the data up to 2007 should be considered. Here, too, the results demonstrate a statistically sig

human interactions (significant at the 99% confidence level).


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0

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400

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800

1000

1200

1400

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1800

1994 1995 1996 1997 1998 1999 2000 2001 200

FIG. 1 - F&W COMPLAINT REPORTS IN NEW JERSEY 1995

Enhanced implemenprogram (garbage coand aversive conditio

y = 318.06x 634393R2 = 0.8338F = 10.03205Si n. = 91%

y = -R2 =F = Si n

Complaints increased from 1995 to Complaints decreased from 1999 to

non-lethal programNUMBERO

FCOMPLAINTS

YEAR


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0

200

400

600

800

1000

1200

1400

1600

1800

2000

1994 1995 1996 1997 1998 1999 2000 2001

FIG. 2 - F&W COMPLAINT REPORTS IN NEW JERSEY 19+ POLICE RECORDS

In 2001 F&W initiated the use of police reports in their analyses

F&W reports

Police reports

NUMBEROF

COMPLAINTS

YEAR


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0

500

1000

1500

2000

2500

3000

3500

1994 1995 1996 1997 1998 1999 2000 2001

FIG. 3 - F&W COMPLAINT REPORTS IN NEW JERSEY 19+ POLICE REPORTS + TOTALS

A second source of data collection in 2001-2003 F&W combined the F&W complaints and police complaints 2001-2003 The total line (blue) between 1999 and 2001 is meaningless/misleading F&W reported a surge in complaints in 2003 Conditions cannot be changed in the middle of an experiment F&W data from 1995 to 2001; then F&W + PD data from 2001 to 2003 Apples vs. oranges Total not scientifically acceptable (apples vs. oranges) Newspapers reported a surge in complaints Falsely reported surge probably contributed to the 2003 hunt decision Actual decrease in complaints

F&W complaints

NUMBERO

FCOMPLAINTS

YEAR


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0

200

400

600

800

1000

1200

1400

1600

1800

1994 1996 1998 2000 2002 2004

FIG. 4 - F&W COMPLAINT REPORTS IN NEW JERSEY 19

The trend in decreasing F&W bear complaints Downward trend significant at 99% confidence

y = -88.367x + 178159R2 = 0.6457F = 12.75678Si n. = 99%

y = 318.06x 634393R2 = 0.8338F = 10.03205Sign. = 91%

NUMBEROF

COMPLAINTS

YEAR


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2000

FIG 5 - F&W BEAR COMPLAINT REPORTS IN NEW JERSEY 19

0

200

400

600

800

1000

1200

1400

1600

1800

1994 1996 1998 2000 2002 2004 20

What happened here?

Surge in 2008 Surge statistically analyzed and shown to be 12 SD from m 2 SD from the mean is an outlier 12 SD from the mean an extreme outlier; not credible; extr

low probability of data points being real; invalid

But is the surge real, despite the statistics? F&W blamed spike on an increase in bear population Need to have a surge in bear population to get a spike like

NUMB

EROFCOMPLAINTS

YEAR


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Black Bear Population Estimates in Northern New Jersey

500

1056

1777

2400 2397

y = 175.25x - 348862

R2

= 0.9046

0

500

1000

1500

2000

2500

3000

3500

4000

1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 200

Year

PopulationEstim

ates

1

No surge in black bear population in 2008 and 2009

F = 37.93873

Therefore, surge in complaints not due to surge in black bear population

Sign. 99%

FIGURE 6


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TABLE ILiterature Search for Mast/Natural Food Supply Scarcity

in New Jersey in 2008 and 2009

Search strategy:((black bear*) OR (Ursus Americanus)) AND (mast ORnatural food)

Searched data bases:Thousands of articles on black bears (Ursus Americanus)

including their natural food supplies.o Biosis Previews

o CAB Abstractso Academic Search Premiero Environmental Sciences and Pollution Management

Coverage: 2007 to presentExtensive databasesNo reports on any study on mast/natural food supply in the forestsof New Jersey.

However, not important:[Only] small year-to-year fluctuations [in bear-human

interactions] may be attributed to . . . natural food scarcity, such asmast failures.1

Possible decrease in natural food supply investigated as cause of reported surge. Literature search inconclusive. But F&W said . [Only] small year-to-year fluctuations [in bear-human interactions] may be

attributed to . . . natural food scarcity. Hence, natural food scarcity ruled out as source of surge

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0

500

1000

1500

2000

2500

2007 2009

Can the surge be explained by errors in collection orinterpretation of data?

~4700 records from 2007 and 2009 inputted onto an Excelspreadsheet and analyzed

Results: F&W had a second source of data collection in 2009,the DEP Communications Center

Again, as in 2003, this is scientifically unacceptable Experiment changed in middle F&W (apples) 1995 to 2007, and oranges 2008 and 2009 Meta-analysis: totally unacceptable to add a new set of data

from a segmented time period to a current set

Scientifically unacceptable

QUAN

TITY

FIG. 72007 VS. 2009 NON-PD SOURCES OF COMPLAINT RECORDS

Note: Zero CC complaintrecords in 2007


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TABLE II

EXAMPLES OF F&W AND CC NOT HAVING THE SAME STANDARDS

Note: Each pair of complaints was from the same complainant on the same day,and with the same reference number; i.e., each pair represents a single complaintbeing evaluated by the two agencies.

09-04-29-0808-02 CC: Nuisance black bear spread trash in yard.09-04-29-0808-02 F&W: Left garage door open bear went in for garbageWeak report by CCSame incident, but CC report equivalent to Category II (garbage), whereas F&Wreport equivalent to Category I (home entry).

09-05-22-0902-38 CC: Bears are roaming throughout the neighborhood.

09-05-22-0902-38 F&W: On back porch - not screened in. Paw prints on house.Weak report by CCSame incident, but CC report equivalent to Category III (sighting), whereas F&Wreport equivalent to Category I (attempted home entry)

09-05-11-1148-28 CC: 3 bears had been in area09-05-11-1148-28 F&W: Bear destroyed shed. Garbage was stored inside.Weak report by CCSame incident, but CC report equivalent to Category III (sighting), whereas F&Wreport equivalent to Category I (property damage plus)

Comparison made between CC and F&W handling of the same complaints Data interpretation weaker from CC than from F&W Data interpretation not standardized Meta-analysis rules: In those rare occasions that data sets may be added,

the data collection and interpretation must be standardized

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FIGURE 8

0

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800

F&W CC

COMPLAINT REPORT MISCATEGORIZATIONS IN 2009

Many more miscategorizations of type by CC than F&W Further testament of non-standardization of procedures

QUAN

TITY

STATE AGENCY


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FIGURE 9NUMBER OF POLICE DEPARTMENTS FAXING COMPLAINT RECORDS

0

5

10

15

20

25

2007 2009

F&W should be the only source of data collection In 2009 21 police departments faxed complaint records to F&W,

vs. only 4 in 2007 This is another example of apples vs. oranges

QUAN

TITY

YEAR


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POLICE DEPARTME AINT RECORDSNT COMPL

FIGURE 10

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800

2007 2009

Large number of police department complaintrecords in 2009 vs. 2007

Shouldnt be any; PD records treated separately

QUANTITY

YEAR


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FIGURE 11

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50

100

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2007 2009

COMPLAINT REPORT DUPLICATES

Many more duplicate complaint records in 2009

QUANTITY

YEAR


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0

100

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500

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2007 2009

COMPLAINT REPORT MISCATEGORIZATIONS

FIGURE 12

YEAR

Many more miscategorizations of type in 2009

QUANTITY


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FIG. 13 F&W COMPLAINT REPORTS IN NEW JERSEY 1AFTER DUPLICATION, MISCATEGORIZATION AND PODEPARTMENT RECORDS WERE REMOVED

0

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400

600

800

1000

1200

1400

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1800

1994 1996 1998 2000 2002 2004 2006

y = -57.459R2 = 0.4204F = 5.8030Sign = 96%

Attempt to repairF&W analysis Remove record duplication Remove miscategorization of type Remove police department records

Results: A decreasing trend at the 96% confidence level, no

NUMBEROFCOMPLAINTS

YEAR

* The analysis was on 2007 and 2009 data. It was decided to leave the 2008 data point out of this graph until such time as it , too, would have undergon


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1000

1200

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1994 1996 1998 2000 2002 2004 2006

FIG. 14 F&W BEAR COMPLAINT REPORTS IN NJERSEY 1995 2009 AFTER REMOVAL OF AL

COMMUNICATION CENTER RECORDS

y = -85.569x + 17R2 = 0.7236F = 20.94384Si n. = 99.8%

Attempt to repairF&W analysis Only remove Communication Cent

Results: A decreasing trend at the 99.8% cosurge

NUMBEROF

COMPLAINTS

YEAR


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0

200

400

600

800

1000

1200

1400

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1800

1994 1996 1998 2000 2002 2004

Attempt to repairF&W analysis Acknowledge that the 2008 and 20

flawed; delete all 2008 and 2009 d

Results: A decreasing trend at the 99% co

FIGURE 15F&W COMPLAINT REPORTS IN NEW JERSEY 199

(ALL 2008 & 2009 DATA IGNORED)

YEAR

NUMBEROFCOMPLAINTS


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CONCLUSION

There was a reported surge in bear incidents in 2008 and 2009. The cause of the reported surge in 2009 was investigated. It was not caused by a surge in bear population. It was not caused by a decrease in bears natural food supply. It was caused by a combination of scientifically unacceptable practices:

multiple sources for collecting and interpreting the data in 2009 (as compared to 2007) many duplicate records in 2009 (as compared to 2007) frequent miscategorizations of type in 2009 (as compared to 2007) many faxed police department reports in 2009 (as compared to 2007)

The collection and interpretation of data in 2009 were scientifically flawed. When adjustments were made to correct these errors, linear regression analyses of the

resulting data demonstrated that from 1999 to 2009 there was actually astatistically significant decrease in complaints, not an increase.

The data in this report are consistent with the data from other reports, includingstudies nationwide, demonstrating that the implementation of non-lethal means,such as garbage control, bear education, and aversive conditioning is effective inreducing serious bear incidents.

The finding that complaints decrease while the bear population increases demonstrates that there is no relationship between the number of bear-related

complaints and the bear population. (The relationship is between the amountof available human-based food and the bear population.)

is consistent with previously shown data that bear hunts (i.e., decreasing thebear population) have no effect on the number of complaints.

is contrary to the hypothesis that the bear population needs to be culled inorder to decrease complaints.

demonstrates that in New Jersey people are learning how to co-exist withblack bears.

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NEXT STEPS AND RECOMMENDATIONSo It is a poor idea having more than one government agency collecting and interpreting

the data, unless their Code of Practices has been standardized. Directives to PDs andthe CC must be reviewed and shown to be consistent with F&W standards.

o Based on the authors data, there is no justification for implementation of a bear hunt ascalled for in the current Black Bear Management Policy. The number of complaints isdecreasing, not increasing. If an increase in complaints is the justification of aproposed bear hunt in 2010, then the proposal for a hunt should be rejected.

o The current downward trend of complaints can continue without great effort; most ofthe complaints are related to human activity that should be easily corrected:

- appropriate garbage/trash handling (e.g., doctoring the garbage or using bear-resistant containers).

- protecting livestock chickens, rabbits, etc. (e.g., installing an electric fencearound the livestock).

- removing bird feeders, other food stuffs and any other attractants (e.g., tree-

dropped fruit, uncleaned grill) from the back yard- not actively feeding and baiting bears- leaving garbage or food-related items in closed garages or sheds, and keeping

kitchen doors closed during peak bear activity- teaching people how to easily get bears out of their back yards, e.g., air horns,pepper spray (research on tazers, remote control miniature vehicles,bear-bangers)

- educating the public that bears are virtually harmless; in the approx. 4700records this author analyzed, there was no confirmation that any human sufferedas much as a scratch from black bears, despite numerous tales of extremeperceived threat.

- enforcing the law; if citizens in bear country knew that they would receive a fineif they violated any part of the law regarding voluntarily or involuntarilyfeeding bears, there would likely be rapid compliance, and a correspondingrapid decrease in the number of complaints per year.

o The government should consider the authors national research, the current researchused in this report, and Rutgers West Milford study. All three studies demonstrate thatgarbage control and bear education will reduce the number of complaints.

o The government should consider the authors national research in making a decisionregarding a hunt. This research clearly demonstrates that bear hunts are ineffective inreducing complaints.

o The government should continue collecting data that will add to the national studydemonstrating that human/black bear interaction can be effectively minimized bygarbage control and other non-lethal methods.

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ACKNOWLEDGMENTS

The author wishes to express much thanks to the following for graciously offering theirtime to input a tremendous amount of data onto an Excel spreadsheet. I couldnt havedone the work without their help.

Raina Ali, Asma Alvi,Saakshi Arora, Michael Bachmann, Judy Brizzolara, HannaCanfield, Sandie Desiderio, Leslie Farer, Farris Farik, Kavya Gorukanti, Nicole Guido,Martyna Hogendorf, Sonia Kaushal, Phyllis Lee, Joseph Lehaf, Dale Levitt, JamieNemeth, Maitri Patel, Kristyanne Patullo, Maria Petrosky, Christine Polonko, MegRadford, Catherine Ruesch, Cheyenne Russo, Steven Seland, Jeffrey Shapiro, TeresaSikorski, Herb Skovronek, Linda Vizcaya, Johnny Voong, Michelle Wenelczyk, I wouldespecially like to thank Dr. Herb Skovronek. Herb and I went back and forth numeroustimes discussing aspects of this report. His comments were both stimulating and helpfulin keeping me on track.

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REFERENCES

(1) Vreeland, JA, Draft New Jersey Fish And Game Council Comprehensive Black Bear(Ursus Americanus) Management Policy,http://www.state.nj.us/dep/fgw/pdf/bear/policy_lit/cbbmp3-10.pdf (2010).

(2) Tavss, EA, Correlation of reduction in nuisance black bear complaints withimplementation of (a) a hunt vs. (b) a non-violent program, Final Report Version 4,http://www.wildlifesciences.org/downloads/Tavss-v4.pdf(2005)(3) Vreeland, JA, Draft New Jersey Fish And Game Council Comprehensive Black Bear(Ursus Americanus) Management Policy,http://nj.gov/dep/fgw/pdf/2005/bearpolicy05.pdf (2005).(4) Vreeland, JA, Draft New Jersey Fish And Game Council Comprehensive Black Bear(Ursus Americanus) Management Policy,http://www.state.nj.us/dep/fgw/pdf/2007/CouncilDraftBearPolicy.pdf (2007).(5) * Linear Regression and Correlation: Outliers, Susan Dean, Barbara Illowsky,http://cnx.org/content/m17094/latest/

(6) KL Tiedemann, Thesis, Rutgers University, May, 2009, in ref. 2.(7) Data from ref 1; 3; New Jersey Fish, Game and Wildlife News, Black bear relatedincidents continue to rise in North Jersey,http://www.state.nj.us/dep/fgw/news/bearsin99.htm; Black bear advisory for North NewJersey Residents, http://www.state.nj.us/dep/fgw/news/bearin99.htm; NJ Division of Fishand Wildlife 2008 & 2009, received from DEP Office of Record Access 3/08/10
http://www.wildlifesciences.org/downloads/Tavss-v4.pdfhttp://cnx.org/content/m17094/latest/http://cnx.org/content/m17094/latest/http://www.state.nj.us/dep/fgw/news/bearsin99.htmhttp://www.state.nj.us/dep/fgw/news/bearin99.htmhttp://www.state.nj.us/dep/fgw/news/bearin99.htmhttp://www.state.nj.us/dep/fgw/news/bearsin99.htmhttp://cnx.org/content/m17094/latest/http://www.wildlifesciences.org/downloads/Tavss-v4.pdf

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