Cabinet-Yaak Grizzly Bear Recovery Area 2013 Research and Monitoring Progress Report
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CABINET-YAAK GRIZZLY BEAR RECOVERY AREA 2013 RESEARCH AND MONITORING PROGRESS REPORT PREPARED BY WAYNE F. KASWORM, THOMAS G. RADANDT, JUSTIN E. TEISBERG, MICHAEL PROCTOR, AND CHRISTOPHER SERVHEEN 2014 UNITED STATES FISH AND WILDLIFE SERVICE GRIZZLY BEAR RECOVERY COORDINATOR'S OFFICE UNIVERSITY OF MONTANA, MAIN HALL ROOM 309 MISSOULA, MONTANA 59812 (406) 243-4903 1 Information contained in this report is preliminary and subject to change. Please obtain permission prior to citation. Please cite this report as following: Kasworm, W. F., T. G. Radandt, J.E. Teisberg, M. Proctor, and C. Servheen. 2014. Cabinet-Yaak grizzly bear recovery area 2013 research and monitoring progress report. U.S. Fish and Wildlife Service, Missoula, Montana. 110 pp. Abstract: Grizzly bear research in the Cabinet Mountains indicated that only a small population remained as of 1988. Concern over persistence of grizzly bear populations within this area resulted in a pilot program in 1990 that tested population augmentation techniques. Four subadult female bears with no history of conflicts with humans were captured in southeast British Columbia and moved to the Cabinet Mountains for release during 1990–94. Three of four transplanted bears remained within the target area for at least one year. Hair snag sampling and DNA analysis during 2002–12 identified one of the original transplanted bears. The animal was a 2 year-old female when released in 1993. Genetic analysis also identified at least 9 first generation offspring and 8 second generation offspring from this individual. The success of the augmentation test program prompted additional augmentation in cooperation with Montana Fish Wildlife and Parks. Seven female bears and 4 male bears were moved from the Flathead River to the Cabinet Mountains during 2005–13. Two of these individuals died during their first year from human related causes. One was illegally shot and one was struck by a train. Four bears left the target area for the augmentation effort. Research and monitoring in the Yaak River began in 1986 with the capture and collaring of 2 grizzly bears. Including those captures, 43 bears have been captured and monitored through telemetry, 1986–2013. Numbers of females with cubs in the Cabinet-Yaak grizzly bear recovery zone (CYGBRZ) varied from 1–4 per year and averaged 2.5 per year from 2008–13. Human caused mortality averaged 1.5 bears per year and 0.3 females per year. Nine known or probable human caused mortalities have occurred in or within 10 miles of the CYGBRZ in the U.S. during 2008– 13. Human caused mortalities during 2008-13 were two adult females (one self-defense and one under investigation), 3 adult males (two illegal under investigation and a black bear mistaken identity), 2 subadult males (black bear mistaken identity and self-defense), and one subadult bear and a cub, both of unknown sex and under investigation. Twelve of 22 bear management units had sightings of females with young during 2008–13. A minimum of 37 bears were identified in the CYGBRZ during 2007–12 after known mortality was subtracted. This minimum was based on captures, genetic information, mortality, and sightings of unique individuals. Sixty-five known and probable grizzly bear mortalities from all causes were documented inside or within 16 km of the CYGBRZ (including Canada) during 1982–2013. Mortality causes, timing, and locations were analyzed for 1983–13. Sex and age specific survival and reproductive rates were updated and reported. Trend monitoring of population vital rates indicated a finite rate of increase (l) for 1983–2013 of 1.000 (95% C.I. 0.907–1.076). For 1983–2013, the population experienced a mean annual finite rate of change of 0.0%. Subadult female survival and adult female survival accounted for most of the uncertainty in l. The probability that the population was declining was 50%. However data from the last 6 years suggest recent positive population growth rates. Capture, monitoring, and habitat use data were updated and reported for 1983–2013. Berry counts indicated greater than average production for huckleberry and lower than average serviceberry, buffaloberry and mountain ash production in 2013. 2 TABLE OF CONTENTS PAGE Abstract 2 Table of Contents 3 Introduction 5 Objectives 6 Study Area 7 Methods 9 Grizzly Bear Observations 9 Survival and Mortality Calculations 9 Reproduction. 10 Population Growth Rate 10 Capture and Marking 11 Hair Sampling for DNA Analysis 12 Radio Monitoring 13 Scat Analysis 14 Isotope Analysis 14 Berry Production Transects 14 Results and Discussion 15 Grizzly Bear Observations and Recovery Plan Criteria 15 Cabinet Mountains Population Augmentation 23 Cabinet-Yaak Hair Sampling and DNA Analysis 24 Grizzly Bear Minimum Numbers 2129 Known Grizzly Bear Mortality 30 Grizzly Bear Mortality, Reproduction, and Population Trend 33 Native Grizzly Bear Survival and Cause-specific Mortality 34 Augmentation Grizzly Bear Survival and Cause-specific Mortality 35 Management Grizzly Bear Survival and Cause-specific Mortality 35 Native Grizzly Bear Reproduction 36 Population Trend 37 Capture and Marking 38 Cabinet Mountains 38 Yaak River 38 Salish Mountains 39 Moyie and Kootenay River Valley North of Highway 3, British Columbia 39 Population Linkage, Kootenai River Valley, Montana 39 Population Linkage, Clark Fork River Valley, Montana. 39 Population Linkage, Interstate 90 Corridor, Montana and Idaho 39 Population Linkage, Highway 95 Corridor, Idaho 39 Selkirk Mountains 40 Cabinet Mountains Augmentation Captures, Montana and British Columbia 45 Radio Telemetry Monitoring 45 Black Bear Linkage Research 45 Monitoring Summary of Native Adult Female Grizzly Bears and Each Augmentation Bear 50 Cabinet Mountains Native Adult Female Bears 50 3 Cabinet Mountains Augmentation Bears 50 Yaak Drainage Adult Female Bears 53 Salish Mountains Adult Female Bears 55 Grizzly Bear Home Ranges 55 Grizzly Bear Denning Chronology 58 Grizzly Bear Use of Habitat Components 60 Grizzly Bear Use by Elevation 65 Grizzly Bear Use by Aspect 66 Grizzly Bear Spring Habitat Description 66 Isotope Analysis 68 Food Habits from Scat Analysis 68 Berry Production 70 Huckleberry 70 Serviceberry 70 Mountain-ash 70 Buffalo-berry 72 Acknowledgments 73 Literature Cited 73 Publications or Reports Involving this Research Program 76 Appendix 1 Grizzly Bear Mortality in the Cabinet Yaak recovery zone, 1983-2013 78 Appendix 2 Grizzly bears captured, observed, photographed, or genotyped by study personnel, 80 1986–2013 Appendix 3 Grizzly Bear Home Ranges 83 Appendix 4 Description of Habitat Components 109 4 INTRODUCTION Grizzly bear (Ursus arctos) populations south of Canada are currently listed as Threatened under the terms of the 1973 Endangered Species Act (16 U.S.C. 1531-1543). In 1993 a revised Recovery Plan for grizzly bears was adopted to aid the recovery of this species within ecosystems that they or their habitat occupy (USFWS 1993). Seven areas were identified in the Recovery Plan, one of which was the Cabinet-Yaak Grizzly Bear Recovery Zone (CYGBRZ) of extreme northwestern Montana and northeast Idaho (Fig. 1). This area lies directly south of Canada and encompasses approximately 6800 km2. The Kootenai River bisects the CYGBRZ, with grizzly bear habitat within the Cabinet Mountains to the south and the Yaak River drainage to the north (Fig. 2). The degree of grizzly bear movement between the two portions is unknown but thought to be minimal. Figure 1. Grizzly bear recovery areas in the U.S., southern British Columbia, and Alberta, Canada. Research on native grizzly bears began south of the Kootenai River during the late 1970's. Erickson (1978) reported the results of a survey he conducted for bears and their sign in the Cabinet Mountains and concluded the population consisted of approximately a dozen animals. A trapping effort in 1979 and 1980 in the same area failed to capture a grizzly bear, but a female and yearling were observed (Thier 1981). In 1983 trapping efforts were resumed and intensified (Kasworm and Manley 1988). Three individual grizzly bears were captured and radio-collared during 1983–1987. Minimal reproduction was observed during the period and the population was believed to be declining toward extinction. To reverse this trend, a formal plan was proposed in 1987 to augment the Cabinet Mountains portion of the population with subadult female bears from outside the area (USFWS 1990, Servheen et al. 1987). Two approaches for augmenting grizzly bears were proposed. The first involved 5 transplanting adult or subadult grizzly bears from other areas of similar habitat to the Cabinet Mountains. Transplants would involve bears from remote areas that would have no history of conflict with humans. The use of subadult females was recommended because of their smaller home ranges and potential reproductive contribution. The second approach relied on the cross fostering of grizzly bear cubs to American black bear (Ursus americanus) females. Under this approach, grizzly bear cubs from zoos would be placed in the maternal dens of black bear females during March or April. The fostering of orphaned black bear cubs to surrogate black bear females has been used successfully in several areas (Alt and Beecham 1984, Alt 1984). During public review of the augmentation program, many concerns were expressed which included human safety, conflicts with other land-uses, and long-term grizzly bear population goals. A citizen’s involvement committee was formed to aid information exchange between the public and the agencies. Representatives of several local organizations donated their time to further this purpose. The first product of this group was a question and answer brochure regarding grizzly bears in the CYGBRZ. This brochure was mailed to all box holders in Lincoln and Sanders counties. In response to concerns expressed by the committee, the augmentation proposal was modified to eliminate cross fostering and to reduce total numbers of transplanted bears to four individuals over five years. The beginning date of augmentation was also postponed for one year to allow additional public information and education programs.