Science Report Princess Royal Kermodes

 

 

Independent Science Panel Report on Princess Royal Kermode Bears

SIMON FRASER UNIVERSITY

DEPARTMENT OF BIOLOGICAL SCIENCES

http://www.sfu.ca/biology/

8888 UNIVERSITY DRIVE

BURNABY, BRITISH COLUMBIA

CANADA V5A 1S6

Telephone: (604) 291-4475

Fax: (604) 291-3496

February 15, 2007

Honourable Pat Bell,

Minister of Agriculture and Lands

PO Box 9043 STN PROV GOVT

Victoria BC V8W 9E2

Percy Starr

Kitasoo First Nation

General Delivery

Klemtu BC, V0T 1L0

Dear Sirs,

Enclosed is our report summarizing the findings of the Scientific Panel that considered the

“Potential for Gene Swamping of Kermode Bears on Princess Royal Island”. The Panel met in

Vancouver on January 19 and discussed a number of biological processes in regard to the issue

of Kermode bears and logging. After thorough discussion of a range of topics, each led by a

member of the Panel who had greatest expertise on the topic, we concluded that: the effect of

logging in the Green River area is not sufficient to change the frequency of the white-phase or

Kermode bear on Princess Royal Island over the term of many generations of bears

On behalf of the Scientific Panel, thank you for the opportunity to contribute our collective

expertise on this important matter.

Sincerely,

Alton Harestad,

Chair of the Kermode Bear Scientific Panel

Professor, Department of Biological Sciences

8888 University Way

Simon Fraser University

Burnaby, BC V5A 1S6

(604) 291-4809, 291-4475

email: harestad@sfu.ca

Potential for Gene Swamping

in Kermode Bears

on Princess Royal Island

Scientific Panel

Workshop Summary Report

Vancouver, BC

February 15, 2007

Kermode Bear Scientific Workshop

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February 15, 2007

Potential for Gene Swamping in

Kermode Bears on Princess Royal Island

— Summary of Findings of a Scientific Panel —

1. Introduction

The kermodei subspecies of the American black bear (Ursus americanus kermodei) is distributed

throughout northwestern British Columbia, on the mainland and on numerous offshore islands. It

occurs in two colour phases, the black phase and the white phase (called Kermode or Spirit

Bears). A concern was raised by the Spirit Bear Youth Coalition, a BC-based environmental

organization, that logging in the Green River watershed might displace resident black bears from

the Green River to Princess Royal Island, and thereby result in the swamping of the expression

of the white-phase gene in the black bears on the island.

The BC Minister of Agriculture and Lands made a commitment to hold a workshop of scientists

with expertise in biology and management of black bears to address this concern. A Panel of

scientists with credible knowledge of the Kermode bear met on January 19, 2007, in Vancouver.

Members of the Panel applied their expertise, knowledge and experience to discuss the potential

for swamping of the white-phase gene due to dispersal of bears following logging.

The Scientific Panel addressed the question: “Will logging in the Green River Watershed result

in the swamping of the white gene (that is, lower its frequency of expression) in black bears on

Princess Royal Island?”

This report, written for the Minister, summarizes the content and conclusions of the Scientific

Panel. It is not intended to reiterate all of the science, or to be a complete record of all that was

discussed. Rather, the report serves as a reference for scientific considerations associated with

the effects of logging on Kermode bears in the vicinity of Green River, and the effects of logging

on bear habitat and populations more generally on BC’s central coast.

2. Panel Participants

Alton Harestad, a professor in the Department of Biological Sciences at Simon Fraser

University, chaired the Panel. Dr. Harestad is a forest wildlife biologist and specializes in habitat

ecology. He was a member of the Scientific Panel for Sustainable Forest Practices in Clayoquot

Sound and has been the ecologist on assessment teams for three Forest Stewardship Council

certifications in BC. He has participated in several scientific advisory committees and panels.

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Tony Hamilton is a bear biologist with the BC Ministry of Environment. He has 25 years of

experience with both black bears and grizzly bears in British Columbia and has worked

extensively in coastal ecosystems, researching the effects of logging on both bear species. Mr.

Hamilton has a strong habitat background and understands bear habitat and population dynamics

in relation to disturbances such as logging.

Kermit Ritland is a professor in the Department of Forest Sciences at the University of British

Columbia. He specializes in population and quantitative genetics. In collaboration with Western

Forest Products, he was involved with a three-year genetic study of Kermode bear populations.

Two papers on genetics of white-phased Kermode black bears resulted from this work: Ritland,

Newton, and Marshall (2001), Inheritance and population structure of the white-phased

“Kermode” black bear; and Marshall and Ritland (2002), Genetic diversity and differentiation of

Kermode bear populations.

Craig Newton is a research scientist with ATG Genetics in Vancouver. He was involved in the

identification of the gene that causes the white-phase of the Kermode black bear. He is a coauthor

of a paper on the genetics of white-phased Kermode black bears, Ritland, Newton, and

Marshall (2001), Inheritance and population structure of the white-phased “Kermode” black

bear.

2.1 Other Attendees

Neil Hamilton, Executive Director, Strategic Initiatives, Integrated Land Management Bureau,

BC Ministry of Agriculture and Lands.

Grant Scott, RPF, Kitasoo Forestry Advisor, on behalf of the Kitasoo First Nation.

Simon Jackson of the Spirit Bear Youth Coalition.

Gordon Erlandson, Erlandson Consulting Inc., served as facilitator for the workshop. Reporting

to the Panel chairperson, Mr. Erlandson served as writer for the Panel in preparation of this

workshop summary report.

Louise Beinhauer, Erlandson Consulting Inc., took workshop notes.

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3. Kermode Bear Genetics

Craig Newton and Kermit Ritland presented results of their own research and other related

research about genetics, inheritance and population structure of the white-phase Kermode bear.

Ursus americanus kermodei is a subspecies of black bear with a black phase and a rare white

phase, both of which inhabit the rainforests on BC’s central and north coasts. The white phase is

often referred to as the Spirit or Kermode bear. Other colour phases of black bears occur in North

America and include brown and cinnamon bears in the western United States and a black-blue

coloured bear in northwestern British Columbia and southeastern Alaska. Occasionally, white

bears have also been observed in northeastern British Columbia and Manitoba. The Kermode

bear was initially considered a separate species in 1905, but since 1928 has been classified as a

colour phase of the black bear, kermodei subspecies (Ursus americanus kermodei).

DNA samples, collected by Helen Davis and her crew, were analyzed from 220 genetically

distinct individual black bears from a total of six west coast islands (Princess Royal, Gribbell,

Hawkesbury, Roderick, Pooley and Yeo) and five adjacent areas on the mainland. Of the bears

sampled, 22 were Kermodes, and only these 22 Kermodes were homozygous for a nucleotide

substitution that causes an amino acid change in the gene Mc1r (a known part of the pathway

that controls the production of the pigment melanin). The research confirms both the role of this

nucleotide difference in causing the coat colour difference, and the recessive nature of white coat

colour (both copies of the gene are required to express the white coat colour). The white phase is

not an albino condition.

The total number of white-phase bears in the study region is estimated to be between 100 and

400 individuals. Frequencies of occurrence of the white-phase allele were substantially greater

on Princess Royal, Gribbell and Roderick islands, occurring in 20% to 50% of bears, but

occurrence was infrequent on the mainland.

The recessive gene is often present in the heterozygous stage, meaning that a black-phase bear

can have one copy of the Kermode gene (of the two possible). Heterozygotes act as a reservoir

for the white-phase gene among the black bear population. In fact, most Kermode genes are

hidden in the heterozygous condition; population genetic theory predicts that if the frequency of

the Kermode bear is less than 25%, there are more Kermode genes present in heterozygotes

(black coloured bears) than in homozygotes (white bears). Only one island (Gribbell) had a

frequency greater than 25% (10 of 23 were white); thus the majority, and probably the vast

majority, of Kermode genes exist in heterozygous black bears.

Some new, but preliminary, analysis of the data using landscape genetic models indicated that

there are six breeding groups of black bears in the region sampled, and that Princess Royal Island

has two of these breeding groups. Previous analyses have assumed that each island is a breeding

group (population). In the new analysis, breeding groups are inferred by the genetic similarities

at 10 microsatellite loci (microsatellites have many alleles at a locus, and are ideal for “genetic

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fingerprinting”). Breeding groups also spanned islands, which is evidence that bears migrate

between the Princess Royal Island and the adjacent mainland in perhaps complex patterns.

The question was posed as to why white-phase bears appear to mate more with white-phase

bears, given that the breeding system in bears is not segregated and is very open. This may well

relate to the spatial relationships of bears, in particular the social tolerance and a high degree of

home range overlap among females. Young females tend to stay close to their natal home range

(i.e., their mother’s home range). This would raise the frequency of mating with another white

bear, particularly in geographic locales where the frequency of expression of the white gene is

relatively high. If bears breed within these breeding groups as the data suggest, then immigration

may have relatively less effect on the frequency of white-phase alleles.

4. Regional Environment and Habitats

Alton Harestad described the regional environment and nature of bear habitat in the vicinity of

Green River and Princess Royal Island. He cited two key references, Blood (1997) and the Coast

Information Team (2004).

The Green River area is on the mainland of the Central Coast, with Princess Royal Island

immediately to the west. Princess Royal is the fourth-largest island on the coast, after

Vancouver, Graham and Moresby islands.

The forested area is dominated by the Coastal Western Hemlock (CWH) Biogeoclimatic Zone

which accounts for about 90% of the land area, with small amounts of the Mountain Hemlock

(MH) Zone in higher elevations. The mainland has proportionally more Mountain Hemlock Zone

than Princess Royal Island. In the eastern portions of Princess Royal and in the Green River area,

the CWH very wet maritime subzone, submontane variant, is widespread at low elevations. The

CWH montane variant is more prevalent at mid-elevations and the MH zone occurs above this

variant. There are extensive areas of scrub forest, avalanche tracts, and bog forest. Commercially

productive forest, from a wood products perspective, is confined mostly to lower slopes and

valley bottoms.

Vegetation available as forage for bears occurs in small estuaries and deltas, riparian sites, beach

fringes, wetlands, bog forest, and avalanche tracts. Eighteen species of berries that occur in

coastal forest ecosystems are used by bears (e.g., salmonberry, salal, huckleberries, blueberries

and elderberries). Old growth forest provides both standing trees and downed wood as structures

for winter dens (e.g., western redcedar), as well as some opportunities for feeding, particularly in

forest openings.

There are at least 27 salmon spawning streams on Princess Royal Island that provide important

sources of abundant, high-quality food for bears from late July through November. Sockeye runs

are small, and small to moderate numbers of coho occur in most creeks. Pink salmon spawn in

most of the streams, and several streams have runs of 5,000 or more. Runs of 1,000 or more

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chum salmon occur in several creeks. Salmon are important for coastal bears because they allow

the bears to deposit enough fat to last them through hibernation. The small estuaries and creeks

on Princess Royal are important for bears, particularly in spring.

The Green River also has a significant salmon run, adequate to support significant numbers of both

bear species, with an average of 10-15,000 pink salmon, 5000 chum and 1000 coho annually. The

pink run has been recorded as high as 60,000 fish by the federal Department of Fisheries and

Oceans. Although the Central Coast region provides excellent bear habitat, the Green River

watershed itself is of moderate value as bear habitat overall, with several high value sites within it.

4.1 Natural Disturbance Regimes

Over most of the Central Coast, stand-replacing disturbances are rare and stands are typically

very old. Death and re-establishment of trees occurs primarily in small canopy gaps of 10 trees

or fewer. These gaps are typically created by a combination of wind, landslide, flooding and

pathogens and comprise approximately 10–30% of the area in old-growth stands.

Detailed study as part of the Central Coast Land and Resource Management Plan found that

wind disturbed 0.3%, and geomorphic disturbances (including landslides, avalanches, and

flooding) disturbed 1.4% of the area. Mean disturbance frequency (proportion of area disturbed

per year) from all sources is less than 0.3% per year.

Geomorphic disturbances such as landslides and snow avalanches are the most important

naturally occurring high-severity, stand-replacing events in the area. These events result in herb

and berry fields that are important seasonal habitats for bears. Snapped and uprooted trees serve

an important ecological role as downed wood in both terrestrial and hydroriparian ecosystems

where they provide small pockets of forage as well as some den structures. Hydroriparian

ecosystems link portions of the landscape, forming networks of habitat that provide forage and

cover for bears. Flooding is the key process shaping floodplains and estuaries. Jams of large

woody debris alter flow patterns, create complex channel morphology, and help protect

downstream habitat and back channels from flood scouring.

Two Natural Disturbance Types (NDT 1 and NDT 2) occur in the region. NDT 1 (ecosystems

with rare stand-initiating events) consists of uneven-aged or multi-storied even-aged stands, with

regeneration occurring in gaps created by the death of individual trees or small patches of trees.

When disturbances such as wind and landslides occur, they are generally small and result in

irregular edge configurations and landscape patterns. The mean return interval for disturbances is

generally 250 years for the CWH and 350 years for the MH.

NDT 2 (ecosystems with infrequent stand-initiating events) consists of even-aged stands, but

extended post-fire regeneration periods produce stands with uneven-aged tendencies. Wildfires,

when they occur, are often of moderate size (20–1,000 hectares), with unburned areas sheltered

by terrain features or high site moisture. The mean return interval for these disturbances is about

200 years for the CWH.

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4.2 Seral Stages and Bear Habitat

Bear forage is most prevalent in the early seral stages and in old and mature forests when the canopy

begins to open up. Closed canopy forests (20–80 years old) offer fewer foraging opportunities for

bears. Plant succession after clearcutting would broadly follow the seral stages below:

0–5 years: herb seral stage (sparse seral stage)

5–20 years: very high shrub production

20–40 years: pole sapling stage, the stand closes off

40–80 years: young forest, very little berry production

80–250 years: mature forest, forage production increases

> 250 years: old forest, natural disturbances create openings

However, in partially cut areas where significant numbers of trees are retained within the

cutblock (e.g., under a variable retention harvest regime), responses of plants important as forage

for bears will vary depending on the degree of canopy opening. Berry production may also

benefit as a result of an increase in the amount of light reaching the understory.

5. Forest Harvesting in the Green River Area

Grant Scott presented an overview of the forest harvesting conducted in the Green River

watershed, on behalf of the Kitasoo First Nation.

The Kitasoo First Nation comprises approximately 500 people living in the community of

Klemtu on BC’s Central Coast. The community relies on fishing, aquaculture, eco-tourism and

forestry for employment and economic development. The Kitasoo people have been active in

land use planning discussions and have generated their own land use plan for their traditional

territory. They have worked with other First Nations, the Province of BC, environmental

organizations and industries to create protected areas and implement sustainable forest practices

in their traditional territory. Total area of the Kitasoo traditional territory is 532,000 hectares, of

which 45% (approximately 240,000 hectares) is protected area.

5.1 Green Inlet, Green Lagoon, and Green River Watershed

The forest harvesting proposed by the Kitasoo First Nation was subject to public review in

Klemtu and Prince Rupert, and was specifically reviewed by neighbouring First Nations. No

identified concerns were outstanding before logging began.

Total area of Green River watershed: 23,286 hectares

Total forested area: 8,963 hectares

Total timber harvesting land base: 3,567 hectares

Total mature volume: 2,023,152 cubic metres

Potential harvest per year: 21,400 cubic metres (based on 100-year rotation)

Potential jobs annually: 58

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The Green Inlet, Green Lagoon, and Green River watershed are considered moderate value

habitats for bears overall, with some high-value sites within them, and are more suited to grizzly

bears than to black bears. Black bears do inhabit the area, however, and white-phase bears have

been observed occasionally.

5.2 Kitasoo Forest Company Harvest Plans 2006/07

The Kitasoo Forest Company harvest plan was for 45,000 cubic metres in small variable

retention cutblocks, rather than in clearcuts. This level of harvest translated into approximately

124 hectares in 2006/07, or about 1.4% of the forested area, and 2.2% of the total mature volume

in the Green River watershed.

The variable retention prescription resulted in about 337 cubic metres per hectare being

harvested, and up to 50% of the volume (900–1,000 cubic metres) of each harvested cutblock left

standing. The prescription was designed to mimic natural disturbance types. The area was

helicopter-logged, with no road or log dump requirements. This eliminates the potential for

environmental impacts as a result of these developments. All harvested wood was dropped in the

water and barged out. The harvest areas themselves tend to blend in with the surrounding

landscape because of the highly variable nature of the forest stands in the area (strips of timber in

the low areas, hummocks, wet areas). Natural regeneration is planned because of the small size

of any opening and the care taken when removing trees by helicopter.

The Kitasoo First Nation has no plans to log in the upper watershed or the lagoon area. There are

no plans for further logging in the Green River area at this time, and certainly not for the next

five years.

6. Bear Habitat and Population in the Green River Area

Tony Hamilton described key features of bear habitat on the BC coast and effects of forest

harvesting on bear habitat, with particular reference to logging in the Green River area. He

referred to two publications: the North Coast Land and Resource Management Plan (LRMP)

Information Circular about black bears; and Davis et al. (2006), a paper on the influence of

phenology on site selection by black bears.

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The starting point for consideration of habitat and population effects from forest harvesting can

be drawn from the list of issues of concern about black bears discussed in the North Coast LRMP

Information Circular:

• Mortality risk associated with human food and garbage;

• Mortality risk associated with connected road networks;

• Protection of critical denning and foraging habitat;

• Provision of stable landscape-level forage supply;

• Requirement for suitable escape trees in and near forest openings; and

• Displacement from preferred habitat or habituation as a result of disturbance.

One of the important elements from a bear welfare perspective is the change in food production

at a landscape scale following logging. Given that home ranges are large, 20 square kilometres

for females and up to 300 square kilometres for males, consideration of habitat effects at a stand

level needs to be put in the landscape context. As well, most home ranges overlap seasonally,

particularly where salmon are present as a fall food source.

The forest harvesting that has occurred at Green River may result in some increased food

production within the openings, in response to the variable retention of up to 50% of standing

timber, and because heli-logging results in minimal soil disturbance. As well, some habitat

elements will stay primarily intact, with structural diversity providing sufficient denning and

escape cover to maintain suitable home range conditions for females and cubs. Availability of

mark trees and climb trees should not be affected.

Between 200 and 500 bears per 1,000 square kilometres is a conservative estimate for the density of

black bears in CWH zone of the Central Coast of BC. The Green River itself may have 30 to 40

bears per 1,000 square kilometres, reflecting the fact that the habitat is less well suited to bears than

some other coastal areas. Grizzly bear habitat is moderate and the influence of grizzly bears on black

bears is unclear. Regardless, if the disturbance from logging in the Green River area is translated into

habitat effects and then into population effects, an increase in bear population of less than 1 bear

would be expected. However, such an analysis is not entirely biologically relevant, given availability

of a variety of food sources, the scale of home ranges, movement patterns, and social factors. Hence,

this expected increase is likely an overestimate and was presented at the workshop only to illustrate,

hypothetically, the scale of potential consequence.

Within openings of the scale of logged areas at Green River, only a few species of berries would

be affected. However, bears rely on 18 species of berries in coastal BC, all of which will vary

naturally from year to year. Salmon is the more important fall food for bears, and this resource

also fluctuates annually. Regardless of these variations, coastal bears are not usually considered

to be fall-forage limited. The more important consideration is for food sources during spring and

the habitats logged were not typical spring foraging units.

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At the level of forest retention in Green River area and given the small overall scale of harvest

(total of 124 hectares), there is no anticipated shift in home ranges. If there is an influence, it

would be a shift in activity centres within the home range itself. Given the short-term disturbance

(e.g., noise) during logging operations, the strong affinity of females to their home ranges may

negate any shift in home ranges.

If cumulative impact is a concern, it is important that this be assessed based on an understanding

of the specific disturbance patterns and locations. Different ecosystems have different values for

bear habitat and respond differently over time to disturbance.

7. Summary of Potential Effects of Logging

Panel members applied their collective understanding to the question of potential effects on bear

populations and the potential for bear movement following logging. This section provides a

summary of the Panel’s assessment of the effects of logging in the Green River area with respect

to: bear habitat; the frequency of dispersal by bears and the distances bears will move; how many

bears would emigrate to Princess Royal Island; and the degree to which emigration might be

cause for concern with respect to the expression of the white-phase gene.

7.1 Effects of Habitat Changes on Nutritional, Behavioural, Social and

Demographic Factors

From a habitat perspective, harvesting 124 hectares by helicopter, with a retention prescription

that leaves up to 50% of the timber standing, will result in a slight increase in habitat suitability

in the openings, but not enough to cause behavioral changes or result in demographic

consequences. The magnitude of change is insignificant. If forest harvesting similar to what has

recently occurred within the Green River area were expanded, provided special recognition were

given to the protection of dens and to climb and mark trees, there would unlikely be significant

changes at either the individual bear or the subpopulation levels. The ecosystem-based

management (EBM) approach adopted by the Kitasoo Forest Company has been deliberately

designed to minimize impacts on species and ecosystems.

7.2 Effects of Habitat Changes on Population Size and Productivity of Black

Bears

The population size and productivity of black bears would not change as a result of harvesting of

124 hectares in Green River area, as described. Although in some areas of black bear range in

North America, at full development of early seral stages (i.e., high forage production), there can

be population changes because of increased survivorship, earlier age of breeding by subadult

females, and more cubs per litter. These factors are not operative in the Green River area because

the magnitude of the habitat changes is too small and logging too dispersed.

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Logging occurring to the north and to the south, in the same types of ecosystems, would likely

have similar effects on black bear habitat. If the ecosystem-based management (EBM) regime is

implemented on the Central Coast as proposed, little change in bear habitat quality would be

anticipated. This does not, however, remove concern for logging effects on spring habitat in

lower elevations, even with the EBM regime in place. Concerns about access management and

bear–human conflict over garbage remain, no matter what the forest management regime.

7.3 Effects of Habitat Changes on Site Fidelity by Adult Black Bears, Home

Range Shifts or Abandonment

Black bears have strong fidelity to their home ranges. This fidelity is so strong that wildlife

managers have difficulty translocating bears from areas where they cause problems. Black bears

have been moved more than 100 kilometres away and have returned to their home ranges. Bears

have large home ranges and have different activity centres within their home ranges. Female

bears inherit their home ranges from their mother or grandmother. If something happens in a

portion of a bear’s home range, it will typically shift activity within its home range, unless the

disturbance is on such a scale that the whole home range is affected. Because home ranges are

large, the impact from this small-scale logging should not affect the bears’ fidelity to their home

ranges, either by females (who have small home ranges) or by males. Size and distribution of

harvest blocks are not factors in this case, particularly because the openings retain habitat

suitability after harvest.

With respect to disturbance from the logging practices themselves, most is known about effects

from conventional logging. Some shifting appears to take place with first contact. However,

bears have strong fidelity to their home ranges and will habituate to most human activities. The

logging activity entails the drop-off and pick-up of crews during felling for one week.

Helicopters are present to move the felled timber off the site for a matter of a few hours over a 2-

to 3-day period. Helicopter activity might shift bear use within their home ranges for short

periods, but this would be temporary. There is no evidence that bears would abandon their home

ranges because of logging operations of the scale conducted in the Green River area.

7.4 Effects of Habitat Changes on Adult and Post-juvenile Dispersal

There are two ways that animals could be affected by the logging in terms of movement:

abandonment of the home range and dispersal of juveniles. Post-juvenile dispersal refers to

juvenile bears breaking their ties with their mother, moving and establishing a new home range.

In black bears, this can occur as early as 15-16 months. There are instances of adult dispersal, but

these are considered very infrequent. Abandonment of a home range for all practical purposes

does not occur.

General dispersal patterns are common across a large number of bird and mammal species.

Dispersal distance increases with body size and is farther for carnivores than for herbivores and

omnivores. Based on these broad relationships, the median dispersal distance is 20 kilometres for

a male bear weighing 130 kilograms. The farthest distance noted in a study of 51 subadult black

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bears in Alaska is 27 kilometres and a high proportion of males (18 of 21) disperse from their

natal area. In a study of 20 male black bears in Minnesota, the maximum dispersal distance was

219 kilometres. In both studies, females tended to not emigrate.

7.5 At the Landscape Level, How Many Kermode Bears from the Green River

Area Will Travel and How Far?

Princess Royal Island is within the range of black bears dispersing from the lower Green River

watershed. Terrain will have an influence on the direction dispersing bears will move because

bears tend to follow valleys. Not all bears will necessarily arrive at the ocean and then swim

Graham Reach (approximately 1.2 kilometres across); some may travel up the valley (in a

direction other than toward Princess Royal Island). Black bears could swim across Graham

Reach, but the channel is an impediment to movement and would reduce the likelihood of bear

emigration to Princess Royal Island. Movement of bears to Princess Royal Island likely occurs,

but genetic analyses reveal different frequencies in the white-phase gene and show isolation

between the islands and the mainland. As well, isolation occurs both within islands and within

parts of the mainland. This isolation indicates that interchange between populations of black

bears on islands and the mainland are constrained, but happens naturally from time to time even

in the absence of habitat disturbance.

Female black bears can live about 25 years and give birth every second year beginning in year 4

or 5. Assume that an increase in habitat suitability in the Green River area results in less than 1

additional migrating bear per year. Assume also that half the post-juvenile bears are male, and

therefore only half these bears will migrate. The resulting number must be reduced again by at

least half (perhaps by 75%) because of the choice of direction of travel by dispersing bears, and

because Graham Reach is an impediment to movement. This translates into the potential for

addition emigration to Princess Royal Island by less than 0.1 additional bear per year, or 1

additional bear every 10 years.

7.6 Potential Number of Black Bears Reaching Princess Royal Island and Other

Islands Occupied by Black Bears with High Frequency of the White Phase

in the Short Term and in the Long Term

Increased suitability of habitat translates into the potential for up to 1 additional bear per decade

dispersing to Princess Royal Island, given that the animal will swim the channel and

notwithstanding other influences.

The Panel was generally impressed by how benign the forestry factor is in this area with respect

to the emigration of bears to Princess Royal Island. The potential for emigration is about the

same to Roderick Island, but less likely to Gribbell Island because of the wider channel. These

islands are the other two centres of highest frequency occurrence of the white-phase Kermode

bear.

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7.7 Genetic Consequences of This Rate of Emigration to Princess Royal Island

At the upper end of the spectrum of possibilities (i.e., 1 additional bear moves every 10 years),

the Panel assumed that:

• the minimal habitat changes at Green River can be expressed in bear numbers;

• 1 male bear emigrates to Princess Royal Island every 10 years;

• the male is a homozygous black-phase bear, rather than a white-phase or heterozygous

bear;

• the average generation period for black bears is 10 years.

At a frequency of 1 bear per generation, based on the above assumptions, it can be calculated

that it would take many generations (dozens to hundreds) before a significant change in the

expression of the white-phase gene would occur. For example, for an island population of 500

bears, one homozygous black-phase bear immigrating every generation would cause a 10%

reduction of the white gene frequency after 52 generations or 520 years. Also, based on the

degree of among-island differentiation (as measured by Wright’s Fst) one can indirectly estimate

the “long term” average number of bears that migrate between islands as about two per

population per generation. Thus the potential for an additional bear per generation would

increase gene flow by 50%. However, these are very crude estimates and the actual levels of

historic gene flow may be twice as high or twice as low.

Also, the role of natural selection in maintaining the Kermode condition is completely unknown.

If present, natural selection may counteract any influx of black coat colour genes. For example,

white-phase bears could be more successful fishers because they may be less visible to salmon in

the water. As it is, the relative frequency of the white gene in the face of historical gene flow (2

per generation) is somewhat puzzling, and suggests natural selection. Sexual selection might also

play a role, with white bears tending to prefer other white bears such that areas of high white

frequency are maintained. Other mitigating factors include: movement between breeding groups

on Princess Royal Island; the probability of a heterozygote emigrating; density of populations on

the mainland and on Princess Royal Island; carrying capacity; and the potential that some bears

disperse intentionally to a specific area.

7.8 Potential Extension of the Question to Other Areas

On the broader spatial scale, we can consider logging occurring to the north and to the south of

Green River, in the same types of ecosystems. In these areas, if the ecosystem-based

management regime is implemented, no substantive change to bear abundance and distribution

would be predicted. In part, EBM is designed to maintain wildlife, fisheries, water and other

forest values, as well as allow economic benefits. The lack of bear response is in large part a

result of the management regimes that are practiced.

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February 15, 2007

The EBM regime does not, however, remove the concern for logging in low-elevation spring

habitat, or remove the concerns about access management or bear-human conflict over garbage.

Logging could have a different impact on bears in such areas. Having said this, some anecdotal

information indicates that in the areas of greatest logging disturbance (e.g., in the Terrace area),

an effect on gene frequency would be more likely because of the higher change to bear habitat

suitability. On the other hand, there is also anecdotal information that logging in the Terrace area

has not changed the frequency of occurrence of expression of the white gene.

8. Conclusion and Recommendations

It is the conclusion of the Scientific Panel that: the effect of logging in the Green River area is

not sufficient to change the frequency of the white-phase or Kermode bear on Princess Royal

Island over the term of many generations of bears.

Cautionary Note: The Panel wishes to stress that the use of numbers in this report is to help

bound the upper limits of expectations of impacts, and cautions against the use of these numbers

as implying certainty beyond this intended purpose. Although we use 1 bear per year, the amount

of habitat benefit to bears is likely more in line with an estimate of 0.1 bear per year. As well, the

effects are not necessarily additive, because of the size and distribution of cutblocks in relation to

bear home ranges, use within home ranges and the social system of black bears. No one bear

really benefits very much, and we do not expect a population response. We have purposely tried

to address uncertainty in our deliberations by over-estimating population response and dispersal

rates. The conclusion also captures this uncertainty by the wording “over the term of many

generations of bears.”

8.1 Associated Recommendations

The Panel offers the following associated recommendations.

• The database for Kermode bear should be improved, and this database will continue to

support science-based management of bears. This might include a more systematic sampling

of bear hairs (for DNA) and additional genetic analysis of resulting bear DNA to (1) get a

more precise estimate of the gene frequency of the white-phase gene, and (2) ascertain

whether the gene frequency is changing over the longer term. It is much more efficient to

estimate gene frequency by using the molecular genetic assays than by counting numbers of

white-phase vs. black-phase bears, because the white genes can be counted in the

heterozygous black bears.

• Monitor the number of Kermode and black bears, as well as grizzly bears in the Green River

area through the EBM Working Group. This need not be a total count, but could be an index

of numbers and frequencies.

• Monitor the population of Kermode bears on Princess Royal Island through indices, such as

those designed for the Queen Charlotte Islands.

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Vancouver, British Columbia

February 15, 2007

• There are a suite of proposed EBM objectives for both black bears and grizzly bears on the

Central Coast. The Panel would like to endorse the quick implementation of these already

identified objectives.

• Genetic drift predicts that the Kermode bear would be extinguished over time, since the

probability of eventual loss of a gene equals its current gene frequency, which is relatively

low for the Kermode gene. The current frequency could be a result of an ice-age bottleneck

wherein the white-phase gene accidentally drifted to a higher frequency, with subsequent

decreases of frequency as black-phase genes immigrate. However, this is highly speculative.

The role of natural selection in favouring coat colour is unknown. Further study is needed to

ascertain the adaptive significance of the coat colour difference. Alleles maintained by

natural selection tend to be old. At least, the age of the white-phase gene can be estimated by

examining DNA sequence variation around the gene.

• The Province should assist the Kitasoo First Nation with developing a sampling design and

data collection protocol so that the Kitasoo can collect relevant bear information as part of

their regular weekly field inspections within their traditional territory. The emphasis here is

on the provision of practical sampling criteria and field procedures.

• An assessment could be undertaken with respect to the effects of logging that occurs in

adjacent areas. This need not be onerous and requires the estimation of type and location of

harvest over time. This type of assessment might fit well under the auspices of the regional

strategic plan, as a reasonable planning element. It is not the topic for a scientific panel.

• Recognition of the Kermode bear in the areas north and south of Terrace needs greater

emphasis. These areas could be brought under the same management regime as for other

coastal bear populations.

Kermode Bear Scientific Workshop

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Vancouver, British Columbia

February 15, 2007

Some References Used by the Panel

Blood, D.A. 1997. The white-phase Kermode bear, with particular reference to Princess Royal

Island, British Columbia. Report prepared for Western Forest Products, Vancouver. 32 pp.

British Columbia Ministry of Forests and British Columbia Ministry of Environment, Lands and

Parks. 1995. Biodiversity guidebook: Province of British Columbia, Victoria, BC.

http://www.for.gov.bc.ca/tasb/legsregs/fpc/fpcguide/biodiv/biotoc.htm

Coast Information Team. 2004. The scientific basis of ecosystem based management. Prepared

by the Coast Information Team (CIT), Compendium Team. 118 pp.

scibas-fin-04May04.pdf

Cushman, S.A., K.S. McKelvey, J. Hayden, and M.K. Schwartz. 2006. Gene flow in complex

landscapes: Testing multiple hypotheses with causal modeling. American Naturalist

168:486-499.

Davis H., R. Weir, A.N. Hamilton, and J.A. Deal. 2006. Influence of phenology on the site

selection by female American black bears in coastal British Columbia. Ursus 17:41-51.

Marshall, H.D., and K. Ritland. 2002. Genetic diversity and differentiation of Kermode bear

populations. Molecular Ecology 11:685-697.

Michelfelder, V., and K.P. Lertzman. 2006. Community structure of forage plants consumed by

black bears in Nimpkish Valley, British Columbia. B.C. Ministry of Forests and Range,

Research Branch, Victoria, BC. Technical Report 035.

North Coast LRMP. 2003. Black bears on the North Coast. North Coast Land and Resource

Management Plan, Information Circular. 6 pp.

http://ilmbwww.gov.bc.ca/lup/lrmp/coast/ncoast/docs/Black_Bear_Circular_November_5_

2003.pdf

Ritland, K., C. Newton, and D. Marshall. 2001. Inheritance and population structure of the

white-phased “Kermode” black bear. Current Biology 11:1468-1472.

Rogers, L.L. 1987. Factors influencing dispersal in the black bear. Chapter 5, pp. 75-84 in B.D.

Chepko-Sade, and Z.T. Halpin (editors). Mammalian dispersal patterns, the effects of

social structure on population genetics. University of Chicago Press, Chicago, IL.

Schwartz, C.C., and A.W. Franzmann. 1992. Dispersal and survival of subadult black bears from

the Kenai Peninsula, Alaska. Journal of Wildlife Management 56:426-431.

Sutherland, G., A. Harestad, K. Price, and K. Lertzman. 2000. Scaling of natal dispersal

distances in terrestrial birds and mammals. Conservation Ecology 4(1):16 [on line]

http://www.consecol.org/vol4/iss1/art16

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