BEAR: Table of Contents Overview Life history... 97 Food... 97 Distribution... 98 Management... 98 2010 Statistical Reports Controlled spring bear season harvest... 100 General season black bear harvest... 101 Oregon general bear season and harvest summary... 103 99
Overview Once hunted as a predator and nuisance animal for bounty, the black bear (Ursus americanus) received game mammal status in 1970. Since then bear numbers have increased under a more conservative harvest strategy. However, larger bear populations and statutory changes to management alternatives have increased the complexity of bear management. Color of individual black bears may vary greatly and includes many shades of black and brown. Black is by far the most common color in western Oregon. But nearly 3/4 of bears in eastern Oregon have some shade of brown. The preponderance of brown-phase black bears could explain the occasional grizzly bear sightings reported in northeastern Oregon. Bear Life History Black bear breed primarily in June and July and cubs are generally born in the den during January or February during hibernation. Because lactating females do not breed, alternate year pregnancies are typical in black bear. Black bear litter size varies from one to six cubs, with two young per litter most common. In years of poor food production, litter sizes tend to be smaller. Young generally remain with the female for slightly over one year and disperse as yearlings in the spring, when females breed again. Once born, cubs have a relatively high chance of survival; however, all or part of a litter may be lost to factors such as predation, disease, or cannibalism (primarily by adult male bears). If a female loses her litter, she will generally breed the following season. Oregon Department of Fish and Wildlife 3406 Cherry Ave NE Salem, OR 97303 www.dfw.state.or.us Bears are long-lived animals. In Oregon, bears 20 years old and older have been documented. The fact that a number of animals reach this age indicates that adult survival rates are fairly high. However, survival rates may vary by age class, sex and location. Food Because bears must eat and store 12 months worth of energy in only 8-10 months, their behavior is dominated by a desire to fill their stomachs. As a result, bears have a very diverse diet that includes a wide range of plants and animals. Their annual diet consists mostly of plant material, but bears also will scavenge carrion or kill for food. 100
When a bear emerges from its den, it seeks any abundant food source to replace body mass lost during hibernation, and to build body reserves in preparation for the coming winter. Bear foraging areas change seasonally. In spring, just after emergence from the den, bears may select open hillsides or clearcuts for foraging, because these areas are the first to green up. In some areas, bears may prey on newborn elk calves and deer fawns when they are vulnerable during the first few weeks of life. As the seasons progress, bears often move to utilize more readily available food resources. Bears seek out berries and nuts when and where available. Moist sites are preferred, regardless of the time of year. Early successional vegetation that occurs following forest disturbances such as timber harvest or fire generally provides desirable food concentrations for bear. As forests mature, food production for bears decreases and animals shift foraging areas to those providing the most desirable grasses, forbs, berries and shrubs. Most desirable for bear management are those timber harvest practices that open extensive dense canopies, increase diversity of the plant species that provide foods for bear, leave trees for escape, and maintain large hollow trees and snags for denning. Bears typically forage at night. However as winter denning approaches, bears may forage more during daylight because of the need to store fat reserves. Additionally, bears may forage more during daylight when food availability is poor (drought, late spring, poor berry crop). Distribution Historically, black and grizzly bears (U. arctos) were both native to Oregon; however, the last grizzly bear documented in Oregon was killed in Wallowa County in 1937. Occasionally grizzlies are reported in Oregon but no evidence to substantiate these reports exists. These are likely sightings of light or cinnamon colored black bears. The highest black bear population densities are found in the Coast Range, Siskyou, Cascade, Wallowa, and Blue Mountains. Black bear distribution in Oregon tends to be restricted to forest zones, typifying their preference and need for forest ecosystems. The availability of trees to climb for safety directly influences bear survival (particularly for cubs). Shade provided by forest cover is important to bears for thermo-regulation during hot periods of the year. Stumps and logs are important sources of den sites used for hibernation, birthing, and rearing cubs. Bears tend to prefer heavy cover adjacent to foraging areas for resting. Typically, a bear will hollow out a small bed for resting in a location that is sheltered from environmental extremes. The location of bed sites changes as the bear changes foraging areas. Management Since an annual census of bears is not yet feasible, the department has used other methods of assessing overall population health and the impact of harvest on the population. Monitoring sex and age characteristics of the harvest is biologically sound and used by managers to track trends in overall bear population health, size, and structure. Black bear populations are difficult to estimate because of the animal s secretive nature, relatively low density compared to animals like deer and elk, and their ability to use natural cover. In southwestern Oregon, biologists have been using tetracycline wrapped in bacon to mark bears to estimate the bear population. Once eaten, the tetracycline marks a ring in the teeth similar to a tree ring. Bear teeth submitted by hunters and from bears taken on damage are examined to age the bear and determine if it was marked by tetracycline. Under a microscope and ultraviolet light, the markings on the teeth from the tetracycline can be seen. The ratio of marked to unmarked bears can be used to develop an improved population estimate. In 2005, the bear marking project using tetracycline has been expanded 101
from SW Oregon to statewide. In order for the study to be successful and provide accurate estimates of bear populations, it is essential that hunters provide teeth from harvested bears. Black bear population studies in several states (including Idaho, Alaska, and Arizona) indicate that lightly hunted black bear populations have a high percentage of adult males (30 percent or more), a high ratio of adults to sub-adults (60:40 or more), and a median age of four to five years or greater. Heavily hunted populations had relatively low percentages of adult males, adult to sub-adult ratios favoring subadults, and median ages of four years or less. designated collection site within 10 days of the kill to be checked and marked. All data indicates that current harvest levels are not detrimental to bear population structure. In addition, bear damage problems have increased in recent years, indicating a stable or increasing population. A mandatory check-in of all harvested bear is required in Idaho and Montana for the purpose of population analysis. Beginning in 2008, the skull of any bears harvested must be presented to an ODFW office, or 102
2009 CONTROLLED SPRING BEAR SEASON HARVEST HARVEST HUNT HUNT HUNTER PERCENT DAYS/BEAR NUMBER NAME TAGS HUNTERS DAYS MALE FEMALE UNKNOWN TOTAL SUCCESS HARVESTED 712A WILSON-TRASK 440 269 1617 12 6 18 7 90 716A NORTH CASCADES 385 213 1134 18 4 22 10 52 717A ALSEA-STOTT MT 214 155 1055 4 2 6 4 176 731A SOUTH CENTRAL 220 103 536 2 2 2 268 742 HOOD UNIT 54 30 172 2 4 6 20 29 746A SOUTH BLUE MTS 275 178 826 4 4 2 207 749A WEST BLUE MTS 184 150 752 21 11 32 21 24 752A STARKEY UNIT 220 145 686 4 2 6 4 114 756 WENAHA UNIT 248 138 596 29 29 21 21 756T WENAHA UNIT YOUTH 55 32 143 757A SLED SPRINGS-CHESNIMNUS 275 210 1023 12 14 26 12 39 757T SLED SPRINGS-CHES YOUTH 88 65 243 4 4 8 12 30 759A SNAKE RIVER 440 258 1290 20 10 30 12 43 760A MINAM-IMNAHA 248 179 912 16 8 4 28 16 33 760T MINAM-IMNAHA YOUTH 55 15 75 762A PINE CR-KEATING-CATHERINE CR 440 321 1670 24 4 28 9 60 764 LOOKOUT MT UNIT 44 23 56 3 3 13 19 LSB LIMITED SW SPRING BEAR 3750 2234 13692 170 36 7 213 10 64 SPRING BEAR SEASON TOTALS 7,635 4,718 26,478 345 105 11 461 10 57 103
HUNTER HARVEST PERCENT DAYS/BEAR UNIT/AREA HUNTERS DAYS MALE FEMALE UNKNOWN TOTAL SUCCESS HARVESTED WESTERN OREGON 2009 GENERAL SEASON BLACK BEAR HARVEST 10 517 9783 11 321 4437 12 552 6095 14 891 11333 15 446 4205 17 267 3350 18 1532 20635 53 18 71 5 291 NORTHWEST 4,526 59,838 53 18 71 2 843 20 1212 12848 23 552 6985 18 18 3 388 24 1140 15004 18 18 2 834 25 161 2210 26 178 1569 36 36 20 44 27 624 7128 28 677 8269 18 36 54 8 153 29 499 8304 18 18 4 461 SOUTHWEST 5,043 62,317 108 36 0 144 3 433 16 2834 28939 71 36 107 4 270 19 1354 15343 53 53 4 289 21 1122 16376 18 18 2 910 22 855 8642 36 36 4 240 30 1640 18265 71 71 4 257 31 89 1194 34 161 1854 18 18 11 103 39 232 2157 41 570 5060 18 18 3 281 42 107 731 CASCADES 8,964 98,561 249 72 321 4 307 WESTERN OREGON TOTAL 18,533 220,716 410 126 0 536 3 412 104
HUNTER HARVEST PERCENT DAYS/BEAR UNIT/AREA HUNTERS DAYS MALE FEMALE UNKNOWN TOTAL SUCCESS HARVESTED EASTERN OREGON 2009 GENERAL SEASON BLACK BEAR HARVEST 32 125 1568 33 35 214 1443 36 18 178 37 428 4901 18 18 4 272 38 178 2281 40 36 214 43 53 267 44 36 356 45 160 1818 46 748 7930 47 464 5043 48 588 5524 49 588 5488 18 18 3 305 50 856 9516 51 374 3689 52 927 9837 53 285 2353 18 18 6 131 54 392 4099 36 36 9 114 55 213 2121 56 196 1639 57 659 5132 18 18 36 5 143 58 285 3386 18 18 6 188 59 302 2905 18 18 6 161 60 161 1105 61 464 4437 62 268 1746 63 249 2708 64 71 428 65 427 4188 66 392 4223 67 18 36 68 18 178 69 18 125 70 18 36 71 72 374 4687 73 74 53 481 75 249 2940 76 107 677 77 427 4437 EASTERN OREGON TOTAL 11,439 114,120 72 90 162 1 704 STATEWIDE TOTALS 29,972 334,836 482 216 0 698 2 480 105
OREGON GENERAL BEAR SEASON AND HARVEST SUMMARY TAGS HARVEST HUNTER HUNTER DAYS/ DAYS/ YEAR SEASON DATES AREA SOLD HUNTERS MALE FEMALE UNKNOWN TOTAL SUCCESS DAYS HUNTER BEAR 1975 July 01-Dec. 31/ Coast & NE Aug. 01-Nov. 30 Entire State 17,924 16,247 -- -- -- 1,841 11% 148,092 9 80 1976 Aug. 01-Dec. 31/ Coast & NE Aug. 01-Nov. 30 Entire State 14,660 11,043 -- -- -- 1,074 10% 102,557 9 95 1977 Aug. 01-Dec. 31/ Coast & NE Aug. 01-Nov. 30 Entire State 15,847 12,883 -- -- -- 920 7% 133,570 10 145 1978 Aug. 01-Dec. 31 3/4 of State 8,770 1 No Survey -- -- -- 506 -- -- -- -- 1979 Sep. 01-Nov. 30 3/4 of State 15,705 1 11,324 -- -- -- 812 7% 118,338 10 146 1980 Aug. 23-Nov. 30 Entire State 14,762 1 11,072 -- -- -- 958 9% -- -- -- 1981 Aug. 29-Nov. 30 Entire State 15,503 1 10,124 -- -- -- 783 8% 113,722 11 145 1982 Sep. 04-Nov. 30 Entire State 21,586 1 16,756 -- -- -- 1,313 8% 196,713 12 150 1983 Aug. 27-Nov. 30 Entire State 25,474 1 20,500 -- -- -- 1,420 7% 314,315 15 221 1984 Aug. 25-Nov. 30 Entire State 26,753 1 No Survey -- -- -- (1,350) 2 -- -- -- -- 1985 Aug. 24-Nov. 30 Entire State 25,863 1 No Survey -- -- -- (1,250) 2 -- -- -- -- 1986 Aug. 23-Nov. 30 Entire State 25,928 1 20,748 800 476 100 1,376 7% 239,346 12 174 1987 Aug. 22-Nov. 30 Entire State 25,496 1 17,666 600 277 77 954 5% 202,879 11 213 1988 Aug. 20-Nov. 30 Entire State 20,771 1 15,920 501 236 66 803 5% 169,335 11 211 1989 Aug. 26-Nov. 30 Entire State 19,467 1 16,781 417 216 31 664 4% 202,125 12 304 1990 Aug. 25-Nov. 30 Entire State 20,375 1 17,080 596 274 18 888 5% 217,459 13 245 1991 Aug. 24-Nov. 30 Entire State 12,020 3 9,569 733 388 51 1,172 12% 117,616 12 100 1992 Aug. 29-Nov. 30 Entire State 16,573 1 11,882 555 237 13 805 7% 160,004 13 199 1993 Aug. 28-Nov. 30 Entire State 17,190 1 13,749 841 323 15 1,179 9% 183,666 13 156 1994 Aug. 27-Nov. 30 Entire State 17,242 1 13,672 905 280 65 1,250 9% 198,363 15 159 1995 Aug. 26-Nov. 30 Entire State 13,981 1 12,506 474 140 10 624 5% 173,765 14 278 1996 Aug. 24-Nov. 30 Entire State 22,194 4 20,672 552 272 56 880 4% 282,670 14 321 1997 Aug. 30-Nov. 30 Entire State 23,819 1 20,755 503 138 8 649 3% 238,514 11 368 1998 Aug. 29-Nov. 30 Entire State 27,310 1 26,235 556 264 16 836 3% 382,127 15 457 1999 Aug. 28-Nov. 30 Entire State 34,697 1 27,552 568 264 24 856 3% 379,639 14 444 2000 Aug. 01-Nov. 30 5 Entire State 37,506 1 34,418 676 277 24 977 3% 489,337 14 501 2001 Aug. 01-Nov. 30 5 Entire State 39,971 1 36,893 379 216 30 625 2% 553,970 15 886 106