history of non-native mammal management on kodiak national ... · u.s. fish & wildlife service...
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U.S. Fish & Wildlife Service
National Wildlife Refuge System
History of Non-native Mammal
Management on Kodiak National
Wildlife Refuge McCrea Cobb, Wildlife Biologist
Kodiak National Wildlife Refuge
U.S. Fish & Wildlife Service
National Wildlife Refuge System
Why introduce new animals? • New source of protein
and sport hunting – “easier rugs and
roasts should be available and in more places”
– “improving on a paradise of game”
• Domesticated species • Food for other
introduced animals
U.S. Fish & Wildlife Service
National Wildlife Refuge System
Introductions in AK • Long history
– Russians introduced foxes to islands in mid-1700s.
• Peaked in the 1920s – AK Game
Commission (1925) • FWS took lead in
1940 • State control in 1959
U.S. Fish & Wildlife Service
National Wildlife Refuge System
Species Release Date Release Site Current Status Sitka Black-tailed Deer 1887,1930, 1934 Long & Kodiak Island ~50-80,000 (?) Black Bear c.1922 Spruce Island XX Reindeer 1924 Alitak Bay ~300-350 Muskrat 1925 NE Kodiak, Afognak (Chiniak Bay) Roosevelt Elk 1929 Afognak Island ~600 (2011) Beaver 1925 & 1929 Kodiak & Raspberry Is. ~30-50,000 (?) Snowshoe Hare 1934 Kodiak & Afognak Is. ~100,000 (?) Raccoon pre-1936 & 1980 Long & Kodiak Islands Likely XX Mountain Goat 1952-53 Hidden Basin, Kodiak ~2,500 (2011) Marten 1952 Afognak Island ~2-3,000 (?) Mink 1952 Kodiak Island (Karluk) XX Red Squirrel 1952 Afognak & Kodiak Is. ~10-15,000 (?) Ground Squirrel ? Kodiak? 1000s Spruce Grouse 1957 & 1959 Woody Island XX Dall Sheep 1964-65 Kodiak Island XX Moose 1966-67 Kodiak Island XX European Wild Hog 1984 Marmot Island XX Canada Goose 1986 Shuyak Is., Spiridon 1000s
U.S. Fish & Wildlife Service
National Wildlife Refuge System
Irruptive Population Growth • General trend in
growth similar across many introduced populations – Limited predation – Abundant resources
• Examples of this pattern worldwide – New Zealand thar – Kaibab deer
U.S. Fish & Wildlife Service
National Wildlife Refuge System
Sitka Black-tailed Deer • 1924, ‘30, ’34:
• 25 deer from SE AK to Long Island and Kodiak
• 1940-50s: • Population limited to
northern Kodiak • 1960-70s:
• Deer disperse across Kodiak
U.S. Fish & Wildlife Service
National Wildlife Refuge System
Sitka Deer (1980s – current) • Population
limited by winter conditions – High mortality
during cold, wet, long winters
• Harvests average ~8,000/year
• ~50-80,000 deer
U.S. Fish & Wildlife Service
National Wildlife Refuge System
Feral Reindeer • 1924:
– 32 introduced to Lazy Bay, Kodiak
– Managed by Akhiok residents
• Herd peaked at 3,000 in 1950
• Herded until 1961 Red River 1945
U.S. Fish & Wildlife Service
National Wildlife Refuge System
Feral Reindeer • 1965-1990s:
– Declared feral – Open season and
no bag limit • 2002:
– same-day-airborne hunting approved
• 2009: – Same-day airborne
prohibited – Reclassified as
“caribou” with goal of 200-500
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Estim
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Lichens extirpated?
No dedicated surveys
U.S. Fish & Wildlife Service
National Wildlife Refuge System
Roosevelt Elk • 1929: 8 calves
introduced to Afognak
• 1952: • ~300 elk and 1st hunt
• 1960: • State assumed
management
U.S. Fish & Wildlife Service
National Wildlife Refuge System
Elk
• 1965: Population peaked at ~1,400
• Fluctuated with winter weather
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1929 1939 1949 1959 1969 1979 1989 1999 2009
Estim
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Popu
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U.S. Fish & Wildlife Service
National Wildlife Refuge System
Mountain Goats • Successful
introduction to Baranof Island
• Efforts to introduce goats to Kodiak began in 1948
• 1952-53: 18 goat introduced to Hidden Basin, Kodiak from Kenai Peninsula
U.S. Fish & Wildlife Service
National Wildlife Refuge System
Mountain Goats • Slow initial
population growth • 2011: est. 2,500
mountain goats • Population
stabilized in north • Draw hunt
• Increasing in south • Registration hunt
R² = 0.98
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Min
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U.S. Fish & Wildlife Service
National Wildlife Refuge System
Kodiak Refuge Founded 1941 • “To protect the native
feeding and breeding grounds of the brown bear and other wildlife”
• Accompanying letter with executive order: – “provide a natural
environment for other forms of wildlife such as elk, reindeer, deer, snowshoe hares, and fur animals such as beaver and muskrat”
U.S. Fish & Wildlife Service
National Wildlife Refuge System
Early management (1940s- 1950s) • Law enforcement and
maintaining populations
• Conservative hunting regs and access allowed rapid growth
• Evidence of impacts to landscape – Browse surveys on
Afognak and Kodiak road system
U.S. Fish & Wildlife Service
National Wildlife Refuge System
Transfer of Authority • Alaska statehood
(1959) – State assumes
management control of introduced mammals
– First deer harvested on Refuge
U.S. Fish & Wildlife Service
National Wildlife Refuge System
Refuge Goals Refined • ANILCA (1980)
– Conserve fish and wildlife population in their natural diversities
– Provide opportunities for continued subsistence uses for local residents
– Comprehensive Conservation Plans
U.S. Fish & Wildlife Service
National Wildlife Refuge System
Comprehensive Conservation Plan (1987)
• “Natural integrity” • “Apparent
naturalness” • Exotic species
introduction not permitted – Not native to N.A.
• Management of introduced species not explicitly stated
U.S. Fish & Wildlife Service
National Wildlife Refuge System
Refuge Research • Estimating Deer
Abundances and Impacts – Scan surveys, aerial
hairpile surveys, pellet surveys, FLIR surveys, coastal surveys, alpine surveys, browse surveys
• Mt. Goat surveys
U.S. Fish & Wildlife Service
National Wildlife Refuge System
Comprehensive Conservation Plan (2006)
• “Manage nonnative species to minimize impacts on native resources, while continuing to provide opportunities for harvest”
• “Provide the opportunity for local residents to continue their subsistence use on the Refuge, consistent with the subsistence priority and with other refuge purposes
U.S. Fish & Wildlife Service
National Wildlife Refuge System
Introduced Species Workshop (2000) • Interagency meeting • Priorities defined
– Complete vegetation map
– Study effects of deer and hare on browse
– Study effects of mountain goats on alpine plant communities
U.S. Fish & Wildlife Service
National Wildlife Refuge System
Mountain Goat Research • Management Goal
– Avoid negative impacts to landscape and maintain hunting opportunities
• Study Goals – Determine goat diet and
feeding site selection – Develop nutritional-
based carrying capacity model
– Compare results among populations
U.S. Fish & Wildlife Service
National Wildlife Refuge System
Future Impacts? • Climate change
– Milder winters • Larger introduced
ungulate populations?
• Greater population swings?
• Habitat shifts and novel habitats
• Refuges will need to adapt to a changing environment