Black Bear Population Dynamics and Management in North Carolina, Study notes of History

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Appendix A

Appendix A

HISTORY OF BLACK BEARS

IN NORTH CAROLINA

• A. Physical Characteristics........................................................................ Life History of Black Bears
• B. Habitat Requirements and Food Habits................................................
  • 1. Mountains………………………………………………………...
  • 2. Coastal Plain……………………………………………………...
• C. Home Range and Movements...............................................................
  • 1. Factors Influencing Bear Movements…………………………….
  • 2. Dispersal………………………………………………………….
  • 3. Home Range Size………………………………………………... 7-
• D. Denning Behavior.................................................................................
• E. Reproduction........................................................................................
• F. Mortality............................................................................................ 9-
• History of Black Bear Program (BBP)…………………………………………...
  • A. Historical Records ………...................................................................
  • B. Early Protection………........................................................................
  • C. Early Regulations……….....................................................................
  • D. Creation of the Sanctuary System….……….......................................
  • E. 1981 Black Bear Management Plan..................................................... 12-
  • F. Occupied Range and Current Population Status..…............................ 13-
  • G. Summary of Research Studies….…..................................................... 16-
  • H. Monitoring Activity..............................................................................
    • 1. Documentation of Occupied Bear Range………………………...
    • 2. Human-Bear Interactions................................................................ 18-
    • 3. Bear Cooperator Program............................................................... 20-
    • 4. Hunter Harvest Survey…………………………………………... 22-
    • 5. Harvest Mortality…………………………………………………
    • 6. Non-Harvest Mortality...................................................................
    • 7. Bait Station Survey......................................................................... 24-
    • 8. Mast Survey.................................................................................... 25-
    • 9. Other Population Surveys………………………………………... Appendix A
    • 10. Stakeholder Surveys……………………………………………...
  • I. Management Activity........................................................................... - 1) Role of Hunting in Bear Management...................................... 28- - 2) Regulations and Statutes........................................................... 30- - 3) Human-Bear Conflicts.............................................................. 33- - 4) Habitat Management................................................................. 35-
  • J. Education.............................................................................................. 41-
• Literature Cited 44-

Appendix A

Life History of Black Bears

A. Physical Characteristics : In North Carolina, the black bear is usually black with a brown muzzle. Occasionally, a black bear will have a white patch on its chest, also called a “chest blaze.” In other areas of North America, it is more common for black bears to be cinnamon in color or a more rare white. The average length of a black bear is five to six feet and the average height is two to three feet when standing on all fours. On average, adult females weigh between 100 to 300 pounds and adult males weigh between 200 to 700 pounds. The current world record black bear was harvested in Craven County in 1998 and weighed 880 pounds.

B. Habitat Requirements and Food Habits : North Carolina black bears primarily inhabit the Mountain and Coastal regions of the state and are uncommon in the heavily-developed Piedmont region.

The essential habitat components needed by bears are access to food, water, escape cover, den sites, travel corridors and enough space to exist. Bears are commonly associated with forested cover and make use of a variety of forest habitat types to meet all their seasonal needs. Despite expanding human populations and land-use changes, bears have persisted due to their adaptability to a variety of habitat types.

Optimal habitat conditions should be diverse, so that the habitat provides mast producing trees, early successional habitats (i.e., young forests created and maintained by timber/land management practices or other natural perturbations), edges of various successional stages, streamside management zones, and wildlife clearings. Agricultural crops, commonly found in the coastal plain region of North Carolina, can enhance habitat suitability for bears.

Fragmentation of bear habitat can have implications on population viability since fragmentation can restrict bear movements resulting in smaller populations that are more vulnerable to genetic isolation and mortality. The minimum area needed for populations of black bears will differ based on several factors, such as habitat quality and population management objectives (Rudis and Tansey 1995). Based on known and apparently viable bear populations in the Southeast, researchers have suggested that 79,000 acres of forested wetlands and 198,000 acres of forested uplands are needed as the minimum areas to support a black bear population. Another study in eastern North Carolina suggested 99,000 acres were needed in pocosin habitat (Zeveloff 1983).

Black bears must fulfill their nutritional needs for the entire year in 5-8 months for normal body maintenance, storage of body fat for the winter, and production and maintenance of cubs by females (Beeman and Pelton 1980). Researchers have observed that bears in areas that experience mast crop failures suffer from lower reproductive rates (Rogers 1987), decreased yearling survival, and disperse outside their home range (Jonkel and Cowan 1971, Reynolds and Beecham 1980, Garshelis and Pelton 1981, Rogers 1987, Smith and Pelton 1990). Therefore, feeding is one of the most important activities bears participate in and is reflected in the areas they use (Pelchat and Ruff 1986).

1. Mountains: Black bears in the Southern Appalachian Mountains of western North Carolina survive in a predominantly oak-hickory and mixed mesophytic forest. These

Appendix A. History: Habitat and Food Habits cont.

refuge from man and hounds. Escape habitat may be one of the most critical habitat components for black bears on the coast (Jones et al. 2003).

C. Home Range and Movements : Burt (1943) provided one of the first descriptions of home range, which is still widely cited by researchers; home range is “that area traversed by the individual in its normal activities of food gathering, mating, and caring for young. Occasional sallies outside the area, perhaps exploratory in nature, should not be considered as in part of the home range.”

1. Factors influencing bear movements: Several characteristics can affect the size and shape of a bear’s home range. These include sex, age (Reynolds and Beecham 1980, Garshelis and Pelton 1981), kinship (Jonkel and Cowan 1971, Garshelis and Pelton 1981), social behavior (Jonkel and Cowan 1971, Lindzey and Meslow 1977), reproductive status (Hellgren and Vaughan 1989), and food availability and distribution (Jonkel and Cowan 1971, Young and Ruff 1982, Smith and Pelton 1990). Individuals foraging in habitats containing large amounts of food likely have an advantage over those foraging in habitats containing smaller amounts of food because they can reduce the amount of energy they expend in searching for food. Smith and Pelton (1990) stated that home ranges could be indicative of habitat quality and that comparative analyses of the sizes of black bear home ranges in different populations would be useful in evaluating habitats.

Concentrations of hard mast, soft mast, and/or artificial food resources appear to stimulate seasonal change in home range movements. Responses to hard mast failures have resulted in black bears exhibiting increased fall movements and home range expansions (Beeman 1975, Amstrup and Beechum 1976, Garshelis and Pelton 1981, Garris 1983, Pelchat and Ruff 1986, Rogers 1987). Powell et al. (1997) found that both male and female black bears responded to yearly variations in productivity of hard mast in fall. In years when hard mast abundance was great, male and female annual home range size, summer home range size, and fall home range size were smaller than in years when hard mast abundance was low. When mast abundance was low, bears in Tennessee, Idaho, Alberta, and North Carolina increased their movements and expanded their home ranges (Beeman 1975, Amstrup and Beechum 1976, Garshelis and Pelton 1981, Garris 1983, Pelchat and Ruff 1986, Powell et al. 1997).

2. Dispersal: When the female’s offspring are just over a year old, they will separate from their mother sometime after den emergence (April through early June) and disperse until they establish a home range (Rogers 1987, Schwartz and Franzmann 1992). Purported advantages to dispersing include reduction of feeding competition with female kin, reduced mate competition with male kin, and inbreeding avoidance (Rogers 1987). However, these advantages are more applicable to male bears. It appears that female yearlings and subadults do not travel as extensively as males after family breakup, and in fact, often they don’t disperse (Elowe and Dodge 1989, White et al. 2000). Rather they establish their home range adjacent to or within their mother’s home range (Alt 1978, Rogers 1987, Schwartz and Franzmann 1992, Lee 2003).

Appendix A. History: Home Range & Movements cont.

3. Home Range Size: Numerous studies in North America and in North Carolina consistently show that annual home ranges of males are larger than home ranges of females, (Beeman 1975, Amstrup and Beecham 1976, Lindzey and Meslow 1977, Reynolds and Beecham 1980, Alt et al. 1980, Garshelis and Pelton 1981, Hugie 1982, Young and Ruff 1982, Carr 1983, Hellgren 1988, Smith and Pelton 1990, Fuller 1993, VanManen 1994). Male home range size may be function of larger male body size (Harestad and Bunnell 1979, Quigley 1982), breeding behavior (Rogers 1977, Herrero and Hamer 1977), and site fidelity exhibited by females (i.e. females stay in one area, thus males must travel to encounter them; Clark 1991). Male bears likely travel more extensively in search of food to meet the metabolic needs necessary to maintain their larger body size. Other factors affecting range size of male and female bears may be differences in their strategy for maximizing individual fitness. The reproductive success of males likely depends on their ability to breed with several females (Orians 1969, Rogers 1987, Powell et al. 1997). Hence, it is advantageous for promiscuous males to be mobile, less attached to specific areas, and occupy large areas that overlap with ranges of many females. The reproductive success of females is not as likely to improve by breeding with many males, so females could maximize fitness through detailed knowledge of resource abundance, phenology, and location within their home range (White 1996). Thus, they are less mobile, occupying areas only extensive enough to ensure adequate food for self-maintenance and the development of young (Amstrup and Beecham 1976).

Several studies have been conducted in North Carolina since the 1970’s (Table 1). Based on these studies, the average home range is 13 km^2 for coastal females and 110 km^2 for coastal males; 14 km^2 for mountain females and 47 km^2 for mountain males.

Appendix A. History: Home Range & Movements cont.

dens resulted in 15.5% savings in energy expended for body maintenance compared to ground dens (Lentz et al. 1983). Tree dens provides insulation and increased protection from weather elements and disturbances versus ground dens. Bears will also utilize a hollow log on the ground, the cavity formed in the ground as the result of a wind-blown tree, a dug-out ground cavity, a natural cavity under a rock outcropping or simply a bed on top of the ground in a thicket.

Bear usually begin to enter their winter dens in mid-December and emerge in late March or early April. Bears in eastern North Carolina entered dens as early as November and as late as January. Weather and food availability can affect timing of den entrance and den emergence. Females typically hibernate longer than males. Females with cubs emerge from their dens last in spring; emergence is dependent on weather and cub development. A female bear will emerge from her den once her cubs are capable of leaving the den and following her.

In its simplest definition, hibernation is a specialized reduction in metabolism brought about by low food availability and/or low temperatures. Several body changes occur to bears during hibernation. These include lower heart rates, constriction of blood vessels, suppressed shivering, reduced breathing, lower oxygen consumption, and lower body temperature. Bears drop their body temperatures by 10-15 degrees in most cases. In addition, bears do not consume food, defecate or urinate during hibernation. During hibernation bears are lethargic, but can be easily disturbed and are in full charge of their faculties within seconds of the disturbance.

E. Reproduction : Black bears in North Carolina attain sexual maturity at age 2.5 years old and over half breed at this age (Collins 1973, Carlock, et al. 1983, Powell et al. 1996). Mating occurs from June through early August, peaking in early July (Eiler et al. 1989). Implantation of the blastocyst (i.e. the fertilized egg) is delayed until late fall. Once the blastocyst implants, the true gestation period begins. The overall gestation period for black bears is 45- 60 days and cubs are born from January through mid-Feburary. An average of two to three blind and hairless cubs, weighing less than one pound, are born in winter dens. In North Carolina and throughout North America, younger females (3- and 4-year old) have smaller litter sizes than older females (> 5 years old; Elowe and Dodge 1989, Kordek and Lindzay 1980, Kolenosky 1990, Noyce and Garshelis 1994, Costello et al. 2003, Bridges 2005).

Cubs stay with their mother for their first two winters. When the female’s offspring are just over a year old, they will separate from their mother sometime after den emergence (Rogers 1987, Schwartz and Franzmann 1992, Lee et al. 2003). Once the female’s offspring have separated, the female bear will mate again that summer (Brown 1996). Females mate every other year, resulting in low reproductive potential when compared to other animals.

F. Mortality : Adult black bears have very low natural mortality rates, due to the fact they have no natural predators and they seem relatively unaffected by disease and parasites (Brown 1993). Causes of mortality include legal harvest, poaching, vehicle collisions, depredation permit kills, starvation, and intra-specific predation. Of these, human-induced mortality is the greatest source of black bear mortality in North Carolina (Figure 1). Various factors increase

Appendix A. History of BBP

a bear’s vulnerability to mortality, such as increased access (i.e. roads) into bear habitats and increased movements by dispersing bears or bears in search of food sources.

Figure 1. Causes of mortality among bears sampled by NCWRC from 1969 through 2010.

There have been few studies examining survivorship rates on black bears in North Carolina and the Southeast. Hellgren and Vaughan (1989) estimated annual survival rates of 0.87 for females (>2.5 years old) and 0.59 for males (>2.5 years old) in the Great Dismal Swamp. From 1981 through 2007, survival rates of female bears in the Pisgah Bear Sanctuary in the southern Appalachian mountains of western North Carolina ranged from 0.59 to 0. (Brongo et al. 2005). Powell et al. (1996) calculated the proportion of radio-tagged bears surviving from each age to the next and found survivorship ranging from 0.60 to 0.75 for bears in the Pisgah Bear Sanctuary and adjacent huntable areas (Table 2).

Table 2. Mean survivorship for bears in the Pisgah Bear Sanctuary and adjacent areas (1981- 1990). Bear age (years)

Survivorship (SE) n

1 0.75 (+0.14) 12

2 0.73 (+0.12) 15

3 0.62 (+0.12) 16

4 0.67 (+0.15) 9

5 0.60 (+0.22) 5

6+ 0.73 (+0.12) 15

Overall, survivorship is higher among females than males, with males more vulnerable to mortality due to increased dispersal distances, increased movements during breeding season, and bear hunters selectivity towards male bears. Survivorship rates reported in North Carolina were similar to what has been observed in other states. Based on bear population growth that has occurred since the early 1980’s, the reported survivorship rates of North Carolina bears appear to allow a growing bear population.

Appendix A. History of BBP cont.

B. Early Protection : The first real protection for bear populations in North Carolina began with the establishment of the Great Smoky Mountains National Park (GSMNP) in 1936 and the creation and expansion of National Forests in North Carolina beginning in the 1930’s and 1940’s. The GSMNP was the first bear sanctuary in the state with over 300,000 acres of habitat (on the North Carolina side) protected from hunting, logging, settlement, and development. Although National Forests continued to be hunted, vast areas of habitat were protected, and the forests that had been decimated by extensive logging began to recover.

C. Early Regulations : Hunters were responsible for initiating regulations to protect and manage bears in North Carolina. The first statewide hunting season for bears was established in 1927, and ran from October 15 to January 1 with no bag limit. Since that time, several regulations and statutes have been enacted and/or modified, with several of these occurring in to better address bear management goals.

D. Creation of the Sanctuary System : One of the most important developments in the recovery of black bear populations in North Carolina began in 1971 with the creation of a bear sanctuary system. Twenty-eight bear sanctuaries were established to close approximately 800,000 acres of habitat to bear hunting. The idea behind the sanctuary system was to protect core areas of habitat that encompassed the relatively small home ranges of breeding females. The females would reproduce in the sanctuaries, and bear populations would increase and expand into surrounding areas. The bear sanctuary system, which North Carolina was the first North American jurisdiction to implement, has been one of the most successful and important innovations in the history of bear management in North America and has been a primary factor in the recovery of bear populations in this state.

E. 1981 Bear Management Plan: The 1981 Black Bear Management Plan contained sections addressing nine topics: 1) History, Status, and Distribution, 2) Surveys for Black Bear, 3) Research Needs, 4) Population Management, 5) Habitat Management, 6) Conservation Education, 7) Sportsman Interaction, 8) Management Policy, and 9) Management Priorities.

Many of the specific recommendations addressed in the 1981 Plan have been implemented by the NCWRC and are now considered a normal part of our statewide Black Bear Program. For example, we annually collect teeth and reproductive tracts to analyze age structure and reproductive output. The plan listed 14 management priorities (Table 3). Looking back 26 years after the completion of the 1981 plan, it is clear that many of these recommendations have been met successfully while the priority of others may have changed. In our 2007 BBMP, we build upon the concepts developed in 1981 and identify objectives appropriate for black bear management in the 21 st^ Century.

Appendix A. History of BBP cont.

Table 3. Management priorities identified in North Carolina’s 1981 Black Bear Management Plan. Listed in Order of Importance

1. Preserve key habitat types such as pocosins, Carolina Bays and hardwood swamps.
2. Continue to monitor the population with appropriate surveys.
3. Establish seasons in several eastern counties.
4. Complete sanctuary evolution study in process.
5. Formulate procedures for handling bear-human conflicts and depredation problems.
6. Prepare an annual Big Game harvest report.
7. Continue to stress habitat manipulation.
8. Review and improve the Wildlife Cooperator Agent Program.
9. Determine the effects of human disturbance on bear populations.
10. Review cub and baiting laws.
11. Revise life history and management slide program and hunting pamphlet.
12. Determine need for restoration areas and formulate guidelines for establishment.
13. Complete a life history and management pamphlet in 1981.
14. Complete a bear range map in 1981.

F. Occupied Range and Current Population Status :

1. Occupied Range: The WRC defines black bear range as a geographic area capable of supporting black bears throughout all seasons of the year and is considered to be occupied when there is evidence of reproducing females. Although the seasonal and incidental range of the black bear population fluctuates annually, the occupied range moves at a slower pace as females expand or move home ranges.

The occupied range of the black bear in North Carolina has continued to expand since the inception of management strategies in the early 1970s and black bear populations were recovering by the late 1980’s and early 1990’s. Harvest reports, vehicle mortality, and bear range surveys indicates that the number of bears has increased and occupied range continues to expand (Figures 2 and 3). Today’s occupied range probably represents the largest geographic distribution of black bears in the State in over 150 years.

0

5,

10,

15,

20,

25,

30,

35,

1971 1981 1991 2001 2010

Occupied Bear Range (mi

2 )

Year

Coast Mountains State

Figure 2. Occupied Black Bear Range in North Carolina (mi^2 ), 1971-2010.

Appendix A. Population Status

2. Population Status: Success of the bear sanctuary program and management efforts began to yield benefits as harvest numbers increased each year, and bear range maps prepared by NCWRC biologists began to indicate an expanding population. Bear populations in North Carolina began to rebound in the mid-1980s (Figure 4). By the mid-1990’s, the number of bear-human conflicts began to increase, and it became apparent that black bears were much more adaptable to the presence of humans than anyone had anticipated (Figure 5).

0

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4000

6000

8000

10000

12000

14000

16000

Number of bears

Mountain Coastal Statewide

Figure 4. Estimated Black Bear Population in North Carolina, 1980-

0

100

200

300

400

500

600

700

Number of Complaints/Sightings

Year

Figure 5. Number of bear complaints and observations recorded by NCWRC District Wildlife Biologists in North Carolina, 1993-2010.

Appendix A. Population Status cont.

Bear populations in North Carolina in 2012 continue to thrive in many areas and expand their populations into previously unoccupied habitats. Loss of habitat and increased human development continue to be the most critical concerns for the future of bears in North Carolina. Social Carrying Capacity (SCC; i.e., how many bears are people willing to tolerate) is now considered to be the primary limiting factor for bears in many areas of the state.

Many of the old beliefs that bears could not adapt to human development and increasing numbers of roads and highways began to fade as bears started to appear in areas of high human activity. Human-bear conflicts began to rise substantially in the 1990s, primarily in residential areas of western North Carolina. Bear mortality from vehicular accidents also began to increase, primarily in eastern North Carolina, because of the combined effect of more bears, more roads, and more traffic. Residential developments became, in effect, small bear sanctuaries because hunting was not allowed or was unfeasible. Bears that grow-up in protected areas without experiencing the negative behavioral effects of being chased by dogs and exposed to hunting often lose their fear of people. Loss of habitat to residential, suburban, and urban development is the most critical problem facing black bear populations in North Carolina today. Protection of additional large blocks of habitat through public land acquisition and conservation easements is essential for the future of bears in the state.

North Carolina’s mountain and coastal bear population growth is stabilizing to slightly increasing. Both populations continue to move into previously unoccupied habitats on the periphery of traditional core habitat areas. There are probably more bears in North Carolina today than there have been at any time in the last 100 years. NCWRC biologists now view bear managements’ critical questions in terms of SCC rather than biological carrying capacity (i.e., how many bears habitats can support). Based on the increase in human-bear interactions reported in western North Carolina, some areas of the state may have already reached or exceeded SCC. Educating the public on issues relating to bear/human interactions is a very important aspect of bear management today, but the challenge for biologists of the future may rest on finding ways to stabilize or reduce bear populations in and around areas of high human population.

G. Summary of Research Studies : The results of a status survey in 1967 prompted the NCWRC to initiate the first bear research study in 1969. The study was initiated by the WRC to collect biological information upon which to examine the steadily declining bear population. North Carolina State University (NCSU) was a cooperative partner in these early research efforts. At the time, the only biological information, such as bear age, was available in VA and PA. Bear range, reproduction, mortality data (i.e. sex ratios, age, weight, etc…), and harvest statistics were among the research topics examined. Several of the studies initiated in 1969 continue today.

In 1972, cooperative studies with NCSU were initiated to analyze black bear movements and home ranges at Camp Lejeune and to study habitat suitability in known bear range. Bears were radio-collared and tracked at Camp Lejeune, and scats were collected in Bladen and Dare counties and analyzed to determine food habits and habitat suitability. Over the years,

Appendix A. Monitoring Activities

H. Monitoring Activities : NCWRC biological staff can assess the status of the bear population through various monitoring indices derived from harvest, non-harvest mortality, scent stations, nuisance activity, and bear observations. Population estimates and growth rates are based on a population reconstruction model (Downing 1980), which estimates the population three years prior to collection of biological data from harvested bears. The information derived from these monitoring activities help NCWRC track trends in the bear population and provides for science-based decision making and biologically-sound management principles,

1. Documentation of Bear Range: Since 1971, WRC biological staff has monitored the areas of North Carolina that are occupied by black bears (Figure 2 and 3). Occupied black bear range is defined as a geographic area capable of supporting black bears throughout all seasons of the year and is generally considered to be occupied when evidence of reproducing females is found. Black bear range maps are updated every ten years using non-harvest mortality reports and bear observations.

2. Human-Bear Interactions: Since 1993, WRC biological staff have recorded human-bear interaction reports and recorded bear observations that occur outside the established bear range (Figure 6 and 7). A human-bear interaction includes both bear observations and conflicts with bears. This information not only aids in tracking bear population trends, behavior and occurrences, but helps the WRC predict when most interactions may occur (Figure 7 and 8) and identify common sources of conflict so that we can properly address human-bear interactions and provide effective technical guidance to resolve conflicts.

District 1

District 3

District 5

District 7

District 9 0

50

100

150

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250

300

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(^1993 ) (^1997 ) (^2001 ) (^2005 ) 2009

Number of Human-Bear Interactions

Year

Figure 6. Number of human-bear interactions by district and by year in North Carolina, 1993 through 2010.

Appendix A. Monitoring Activities cont.

Jan. 1% Feb. 1%

Mar. 3%

Apr. 7%

May 18%

June 18%

July 13%

Aug. 12% Sept. 8%

Oct. 9%

Nov. 6%

Dec. 3%

Other Months 38%

Figure 7. Percentage of human-bear interactions reported to WRC District Wildlife Biologists by month in North Carolina, 1993-2010.

Piedmont

Coast

Mountains 0

Number of human-bear interactions

Month

Figure 8. Number of human-bear interactions by month and region in North Carolina, 1993 through 2010.