Cabinet-Yaak Grizzly Bear Recovery Area 2024 Research and Monitoring Progress Report

Recovery plan monitoring targets include the most recent 6-year tracking of the average number of unduplicated females with cubs (6), distribution of females with young by Bear Management Units (BMUs) (18 of 21 occupied), and human-caused mortality (≤4% of the estimated population). Numbers of unduplicated females with cubs in the Cabinet-Yaak Ecosystem (CYE) varied from 2–5 per year and averaged 3.2 per year, 2019–2024. Sixteen of 22 BMUs had sightings of females with young, 2019–2024. Human-caused mortality averaged 4.2% (2.2 bears per year with1.2 female and 1.0 male), 2019–2024. Thirteen grizzly bears died of known or probable human causes during 2019–2024, including five adult females (under investigation, two self-defense, poaching, and a vehicle collision), one subadult female (management), three adult males (management, property defense, and under investigation), two subadult males (mistaken identity and management) and two cubs (female and male self-defense). No recovery targets were met during 2019–2024.

Sex- and age-specific survival and reproductive rates yielded an estimated finite rate of increase (λ) of 1.017 (95% C.I. = 0.953–1.077, annual rate of increase = 1.7%) for 1983–2024. The probability that the population was stable or increasing was 72%.

Thirteen grizzly bears were monitored with radio-collars during portions of 2024. Research monitoring included seven females (six adults and one subadult) and six males (four adult and two subadults) in the CYE. Grizzly bear monitoring and research has been ongoing in the Cabinet Mountains since 1983 and in the Yaak River since 1986.

Cabinet Mountains research indicated that only a small grizzly bear population remained as of 1988. Concern over persistence of grizzly bears in this area resulted in a pilot program beginning in 1990 that tested population augmentation techniques with four subadult female bears captured in southeast British Columbia for release in the Cabinet Mountains, 1990–1994. Three of four transplanted bears remained within the target area for at least one year. Hair snag sampling and DNA analysis during 2000–2004 identified one of the original transplanted bears and identified at least three first-generation offspring and two second-generation offspring from this individual. Success of the test program prompted additional augmentation with ten female bears and eight male bears moved from the Flathead River to the Cabinet Mountains, 2005–2024. Of 22 bears released through 2024, eight are known to have left the target area (one was recaptured and brought back, two returned in the same or subsequent year). Seven of the 22 bears are known to have died, though one individual was killed 16 years after release. Five individuals are known to have reproduced (3 females and 2 males).

Sixty-two grizzly bears were identified as immigrants or emigrants to or from the CYE from 1983–2024 based on capture, telemetry, and genetic data. Fifty-one individuals (47 males and 4 females) are known to have moved into the CYE from adjacent populations; however, twenty-five of these were killed, removed, or emigrated out prior to any known gene flow. Gene flow has been identified through reproduction by nine immigrants from the North Purcells (eight males and one female) resulting in 28 offspring in the CYE and one immigrant from the NCDE that resulted in one offspring. We also detected one instance of gene flow from the Yaak to the Cabinets and Cabinets to the Yaak.

Berry counts indicated average production for huckleberry, serviceberry, and mountain ash, and below average production for buffaloberry during 2024.