copeland highway project. study area > purcell mountains > 16 miles of highway 95 > 300 km...

COPELAND HIGHWAY PROJECT

STUDY AREA

> Purcell Mountains> 16 miles of Highway 95> 300 km2 > Pacific maritime climate> Elevations range from 540 to 1950 m> Forested with active timber management> Huckleberries and buffaloberries

STUDY AREA

> 3 underpasscrossing structures

2004

3 Objectives

Has highway been a genetic barrier (from B.O.)?

Is highway a movement barrier (from B.O.)?

Are animals using the underpasses?

Has Highway been a Genetic Barrier?

• DNA from 197 different bears (hair snare and trapping)

• Fst = 0.0119 (very low level of genetic divergence)

• At least 3 migrants per generation.

There is no current evidence that the highway has acted as a genetic barrier.

Is highway a physical movement barrier?

RESULTS

Highway as home range boundary

BLACK BEAR SPACE USE

RESULTS

Female black bear

Home range centeredover Highway

14 Highway crossings

Human Development

BLACK BEAR SPACE USE

Is Highway a Movement Barrier?

• Almost half of all radio-collared black bears crossed the highway at least once.

• 2 of 3 radio-collared grizzly bears crossed the highway.

• At least 3 migrants per generation (from DNA work).

At current traffic volumes, highway is not a movement barrier.

Are Animals Using the Underpasses?

• Short Answer: Yes

Are Animals Using the Underpasses?

Longer Answer  Underpass

Species #1 #2 #3 TotalBlack Bear 11 3   14Bobcat 1 2   3Cat 5 5 9 19Coyote 8 14 7 29Dog 1   2 3Elk 12 3   15Hare 45 9 8 62Moose 1   1 2Packrat 1 2   3Racoon 3 5 7 15Skunk 2   1 3Squirrel 3 2   5Swallow 2 5 2 9WT Deer 450 117 30 597

Grand Total 545 167 67 779

Underpass Use: Time of Day

Lies, Damned Lies, and Statistics

Liars, Damned Liars, and Scientists

Probability of crossing in relation to habitat variables

Model R2 Delta AIC__________________________________________________

HumDev 0.308 0HumDev CanCov 0.309 1.81HumDev Water 0.308 1.92HumDev CanCov Water 0.309 3.80CanCov 0.054 24.06Water 0.0019 28.15

y = -17.915x - 13.946

R2 = 0.3076-50

-45

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0

0 0.2 0.4 0.6 0.8 1 1.2

Proportion of Human Development

Lo

g P

rob

ab

ilit

y

y = 12.98x + 12.43

R2 = 0.231

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0 5 10 15 20 25

PDOP

Lo

catio

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Time of Day

Conclusion: Deer use underpasses most in the morning and evening and less during the day.

Conclusion: WTD use underpasses less during the day, but not different than expected during other time periods (p<0.00).

Time of Day

Time of Day

Time of Day

Problem: Variable sunrise/sunset.

• Obtained sunrise / sunset tables.• Used “nautical twilight” to define dusk/dawn

– General outlines may be distinguishable but detailed outdoor operations are not possible; horizon indistinct

– sun 120 below horizon; here equals 1 hr 3 min

• Dawn: + 1 hr 3 min of sunrise• Dusk: + 1 hr 3 min of sunset

Time of Day

Time of Day

Conclusion: Deer use underpasses most at night and least during dawn.

Time of Day

  Observed Expected

Dawn 87 46

Day 127 229

Dusk 133 46

Night 203 229

Chi-square test Compares “Observed” versus “Expected” occurrence. Allocate “Expected” based on length of each time period.

Time of Day

Conclusion: Dawn and Dusk are used more than expected, Day is used less then expected, and Night is used as expected (p<0.000).

Beware of Liars, Damned Liars, and Scientists

...But mostly Scientists.