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Grizzly Bears in the Kootenays Michael Proctor Trans-border Grizzly Bear Project.

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Presentation on theme: "Grizzly Bears in the Kootenays Michael Proctor Trans-border Grizzly Bear Project."— Presentation transcript:

1 Grizzly Bears in the Kootenays Michael Proctor Trans-border Grizzly Bear Project

2 Current and historical North American grizzly bear distribution Shaded area is current distribution

3 Trans-border Grizzly Bear Project A partnership working on both sides of the Canadian – US border Team Canada US Fish & Wildlife Service Idaho Fish & Game

4 What we do: Comprehensive strategy of enhanced management Reduce human-caused mortality Improve linkage Augmentation Education Guarantee habitat security

5 South Purcell and South Selkirk Trans-border populations: small, fragmented, and threatened South Purcell/Yahk 40 bears Declining 3% annually

6 Regional grizzly bear fragmentation in southern Canada Internal dotted lines represent limited female movement – solid yellow (& brown) limited male and female movement, red lines are highways Implications Small Pops - urgent need for linkage mgmt Large Pops - consider linkage mgmt

7 Yahk GBPU

8 Research estimate 1 Population estimates for GBPUs in Purcell Selkirk region 1 Proctor et al BC Gov estimate (159) (148) (44) (58) Hunt quota lowered by BC gov Hunt rate lowered by BC gov

9 20-24 grizzly bears in unit 3 females known dead in last few years + unknown (1:1 ratio) 25% are adult females Dearth of females in Yahk GBPU Yahk GBPU

10 Live capture 1 female capture / 74 trap nights 1 Grizzly capture / 41 trap nights DNA surveys 26 female captures / 3 years of surveys DNA surveys 2 female captures / 3 years of surveys Live capture 1 female capture / 568 trap nights 1 Grizzly capture / 95 trap nights S Purcell GBPU Yahk GBPU Dearth of females in Yahk GBPU supporting evidence Fragmentation – female isolated

11 Access management standards in US What went into them

12 Accepted research Bears avoid roads and human features Motorized vehicles of all kinds and shapes Human developments accompanied by people More human traffic = more avoidance Avoidance buffer is up to 500m Adult females are most important to a population’s health Adult females select habitat with some % (55-68) of secure area Secure habitat defined as areas with no human access (habitat > 500m from motorized access)

13 Mace et al Female HRs Larger study area Are there differences in habitat where females chose to live? YES They contained 56% secure areas no motorized access And average road density ~0.6 km/km 2

14 Mace et al Legal standard 68% of BMUs to be “core” (0km/km 2 ) Average road density – 0.6 km / km 2 19% can have > 1 km / km 2 19% can have > 2 km / km2 Clear conclusion – security selected by females more traffic = more avoidance There is a relationship between human access, mortality, and displacement

15 US Purcell, and Selkirk Mts Concluded 55% core was adequate no more than 33% > 1 km / km 2 no more than 26% > 2 km / km 2 Wakkinen and Kasworm 1997

16 Roads in the Yahk area

17 Grizzly bear management units ~ Size of female home range, used to spread access management around GBPU

18 Grizzly bear management units Roads in the Yahk area

19 Roads in the broader Yahk region Roads in US Yaak

20 Note effect of access management (closed roads) on US Yaak road density Roads in the broader Yahk region

21 Local female grizzly bears selection of “core habitat” as a % of home range core habitat = habitat > 500m from a motorized road 0.38Terri trouble keeping offspring alive 0.45 Marilyn died before reproducing 0.54 Maeve survived & reproduced 0.44Kelly survived & reproduced 0.55 Irish survived & reproduced % core habitatFemale GB Yahk GBPU average 0.29 S Purcell GBPU average 0.53

22 36% 34% 21% 39% 34% Grizzly bear management units and % core The goal = 0.50 – 0.60 % core to support females that survive and reproduce

23 Looking for solutions

24 Resource Selection Function (RSF) modeling To identify high quality grizzly bear habitat for consideration for access management

25 18,000 GPS telemetry locations for 13 grizzly bears 4 females 9 males Trans-border Grizzly Bear Project research

26 Variables Land coverEcological AlpineElevation AvalancheCurvature Index BarrenTerrain rugged index BurnGreenness RiparianSlope Forest coverSolar radiation Forest ageHuman % crown closureHuman developments Old forestHighway Young forestRoads Recently loggedParks Cedar - Hemlock Spruce - Sub alpine fir Douglas Fir Lodgepole pine White pine Deciduous Input variable for Resource Selection Function models – habitat modeling

27 Logistic regression models Exp (β 0 + β 1 *Var 1 + β 2 *Var 2...) 1 + Exp (β 0 + β 1 *Var 1 + β 2 *Var 2 …) Prob (occur) =

28 Higher quality grizzly bear habitat (green shaded) Black polygons encompass “core” habitat. Blue are Hwy 3 linkage areas to consider access management (AM) To use as options for AM to optimize gain for female grizzly bears. Green shaded areas are a composite of male and female habitat during spring and fall. Sex and season partitioning is possible

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