Arctic WOLVES - NWT International Polar Year
Transcription
Arctic WOLVES - NWT International Polar Year
IPY PROJECT: Arctic WOLVES (Arctic Wildlife Observatories Linking Vulnerable EcoSystems) Donald Reid Wildlife Conservation Society Canada, Whitehorse What is Arctic WOLVES ? • International investigation of arctic tundra ecosystems. • Network of wildlife observing stations in Canada, Norway, Russia, Netherlands & Greenland (Denmark). • Repeated measurements of selected parts of the tundra ecosystem for comparisons around the globe and through time. Where in Canada ? Alert Eureka Herschel Island Bylot Island Walker Bay Cape Churchill Akimiski Island Where in Yukon ? North Slope – Inuvialuit Settlement Region 2007 through 2010 Herschel Island ALASKA YUKON Komakuk Beach Yukon Research Goals To better understand how energy flows through the tundra food web. Do predators eat so many herbivores that plants do well, or do herbivores eat most of the plant growth ? To investigate possible effects of climate change on distribution, abundance and timing of species in the food web. What changes have taken place in recent decades ? Climate Change ? ( Bob Sagar, Don Reid) ARCTIC TRENDS • • • • Warmer Temperatures Longer Ice-Free Season Earlier Snow Melt Later Freeze-up YUKON NORTH SLOPE EVIDENCE • Permafrost Melt and Slumping • Increasing Coastal Erosion Frank Doyle Frank Doyle TEMPERATURE TRENDS ( 0.5 Co / decade ) Komakuk mean annual temperature (C) -5 Komakuk Annual Shingle Point -10 y = 0.0509x - 12.401 -15 mean annual temperature (C) -5.0 Shingle Pt Annual -10.0 y = 0.0453x - 11.01 -15.0 -20.0 -25.0 1978 1988 date 1998 mean monthly air temperature (C) -10.0 February -15.0 -20.0 -25.0 -30.0 -35.0 1958 1968 1978 date 1988 1998 2008 -15.0 -5.0 1958 2008 1968 1978 1988 date 1998 10.0 June 5.0 0.0 1958 1978 date 1998 -20.0 mean monthly air temperature (C) 15.0 March 1958 1968 1978 1988 date 1998 mean monthly air temperature (C) -5.0 2008 -10.0 1958 1978 date 1998 -20.0 -25.0 1958 1978 date 1998 1998 2008 0.0 October -5.0 -10.0 -15.0 -20.0 1958 1978 date 1998 November -30.0 -15.0 August 1958 1968 1978 1988 date 1998 2008 December -20.0 10.0 -15.0 1988 date -25.0 15.0 April 1978 -20.0 0.0 -35.0 1968 -15.0 5.0 -30.0 1958 -10.0 July 10.0 -25.0 2008 mean monthly air temperature (C) 1968 mean monthly air temperature (C) 1958 September 0.0 -10.0 -35.0 mean monthly air temperature (C) 0.0 -5.0 -30.0 mean monthly air temperature (C) 5.0 May mean monthly air temperature (C) -15.0 5.0 mean monthly air temperature (C) January mean monthly air temperature (C) mean monthly air temperature (C) mean monthly air temperature (C) KOMAKUK -10.0 -25.0 5.0 -30.0 0.0 -35.0 1958 1978 date 1998 1958 1968 1978 1988 date 1998 2008 Changes in the Food Web ? Herschel Island Food Web SNOWY OWL PEREGRINE FALCON WOLVERINE RED AND ARCTIC FOXES WEASELS SHORTEARED OWL LONGTAILED JAEGER PARASITIC JAEGER GRIZZLY BEAR ROUGHLEGGED HAWK RAVEN AND GULLS CARRION CARIBOU MUSKOX EIDERS SEABIRDS LEMMINGS GEESE PTARMIGAN PASSERINE AND SHORE BIRDS INSECTS HERBS GRASSES AND SEDGES A. Kenney DRYAS SAXIFRAGA WILLOWS F. Mueller MOSSES A. Blachford Vegetation ( Scott Gilbert, Isla Myers-Smith, Dorothy Cooley, Catherine Kennedy, Jill Johnstone ) TRENDS ALREADY REPORTED • Arctic is Greening ( More plant growth each summer) • Shrubs do particularly well. • Lichens lose out IPY WOLVES RESULTS - YUKON • Moderate annual growth (120-270 g / m2 dry matter, vascular) • Shrubs expanding • Lichens declined since 1980s • Change in vigour (structure) of existing species, rather than species turnover Insects ( Maria Leung, Scott Gilbert, Don Reid ) ABUNDANCE (Biomass ) • Six times higher on Herschel I. than Bylot I. ( high arctic ). • Historical trends ? RANGE CHANGES ? Maria Leung • 6 butterfly species on Herschel (2007-09) not previously reported. • 2 new crane fly species. • Northwards range expansion ? Fritz Mueller Lemmings & Voles ( Charles Krebs, Alice Kenney, Scott Gilbert, Don Reid, Maria Leung, Liz Hofer) SPECIES •Normal tundra species: Collared Lemming, Brown Lemming, Tundra Vole. • Komakuk: Northern Redbacked Vole & Singing Vole – expansion north from mountains ? Alice Kenney • Tundra & Barren-ground Shrews fully documented. Fritz Mueller Fritz Mueller Cameron Eckert ABUNDANCE • Limited historical data • Herschel – strong population fluctuations (2 – 50 / ha ). • Komakuk - steady low densities (<3 / ha ). • Same general patterns as in recent decades. • Noteworthy lack of typical lemming cycles on mainland. Fritz Mueller LEMMING WINTER HABITAT • Experiment to increase snow depth with snow fences. • Quality of tundra as winter habitat increases with snow depth, and with earlier autumn snow. Alice Kenney Alice Kenney Frank Doyle Birds ( Frank Doyle, Dave Mossop, Mike Nelligan, Alice Kenney, Darielle Talarico, Alistair Blachford, Maria Leung, Scott Gilbert, Don Reid) NESTING SPECIES • Comparing IPY to mid-1980s. • Declines: Ruddy Turnstone, Red-necked Phalarope, Baird’s Sandpiper. • New nesters: Least Sandpiper, Buff-breasted Sandpiper, Sandhill Crane, Peregrine Falcon. • Possible links to climate: Rising sea levels / flooding of beaches & lagoons; increased vegetation cover; more insect / arthropod biomass. • Independent of climate: Peregrine Falcon Photos: Frank Doyle TIMING OF NESTING • Comparing IPY to mid-1980s • Laying dates vary between years, related to spring temperatures and snow melt. • Median hatch date now earlier for all species, by 3 10 days. • Climate related because of link of timing to snow melt. • Concern of mismatch of hatching with maximum insect abundance. Not an obvious problem in Yukon. Photos: Frank Doyle Savannah Sparrow Lapland Longspur Baird's Sandpiper Semipalmated Sandpiper 2008 Rough-legged Hawk 2007 Peregrine Falcon 1986 Common Eider Greater White-fronted Goose American Golden Plover Long-tailed Jaeger Common Redpoll Horned Lark American Pipit DAY 10 Month 12 14 16 18 20 22 24 26 28 30 2 4 June Range of Hatch Dates in 1986 compared to 2007 and 2008 6 8 10 12 14 16 18 20 22 24 July ( No PEFA nesting records in 1986.) RAPTORS Snowy Owl Herschel I. key nesting site Likely negative effects of increased vegetation Short-eared Owl Competitor with Snowy Owl & other raptors. May benefit from increased vegetation. Peregrine Falcon & Roughlegged Hawk Cliff nesters Up to 50% nests lost during IPY when permafrost “cliffs” collapse. Climate related, but localized, impact. Caribou & Muskoxen ( Don Reid, Dorothy Cooley, Lee-John Meyook, Richard Gordon ) CARIBOU • Porcupine herd and Herschel Island. • Early 1970s none resident, and rare visitors. Humans resident on island. • 1980s to present: Common in summer. 2008 summer: 237 with 41 calves (2.2 caribou / km2 ). • Winter residents in recent decade ( hunted in Dec, Mar and April ). WHY ? Winter food – lichens Immediate access to spring forage • Sustainability of wintering herd ? Lichen decline since 1980s Thaw-freeze snow crusting (forced caribou off island in 2008-09). Fritz Mueller MUSKOXEN • Herschel Island • Early 1970s – none; occasional on mainland • Since late 1980s: Regular in summer; some wintering now. • 2008: 43 including 11 calves ( 0.4 / km2 ) • Wintering animals stayed on Island through 2008-09 thaw-freeze event. • Changes not related to warming climate Frank Doyle Alice Kenney Foxes ( Daniel Gallant, Brian Slough, Don Reid ) ARCTIC & RED FOX • North Yukon area of overlap. • Red fox can out-compete and kill arctic fox. Steve Zack • Has a warming climate provided an advantage to red fox. • Den occupancy surveys in 1970s, 1985-89, and 2008-09 (IPY) show stable situation. No change in abundance of one species compared to another Dens have changed equally between species. Daniel Gallant Daniel Gallant • Warming climate not enough to give red fox an advantage. • Food abundance is strongly limiting both species. Maria Leung SUMMARY of CHANGES Related to Changing Climate: Permafrost Melt & Coastal Erosion – habitat loss Storm surges & higher sea level – habitat loss Vegetation – Increased growth, competition changes, changing habitat structure. Distribution of mobile species – new arrivals, competition changes Timing of events – earlier nesting Not Directly Related to Changing Climate: Changes in Caribou and Muskoxen abundance Changes in some other species – Peregrine Falcon Noteworthy Lack of Change: Most Species – vegetation, birds, mammals Fox species – den occupancy and abundance Principal Researchers on Yukon Project University of British Columbia - Charles Krebs, Alice Kenney, Alistair Blachford University of Quebec at Rimouski – Daniel Gallant, Dominique Berteaux, Elise Bolduc, Laura McKinnon, Joel Bety Lakehead University - Doug Morris, Som Ale, Bill Halliday Yukon College – Scott Gilbert, Dave Mossop University of Alberta – Isla Myers-Smith Wildlife Conservation Society Canada – Don Reid Private Researchers – Frank Doyle, Maria Leung, Liz Hofer, Michael Nelligan, Polly Madsen, Olivier Cimon Principal Collaborators Qikiqtaruk Territorial Park (Yukon Parks) – Richard Gordon, Lee-John Meyook, Edward McLeod, Colin Gordon, Deon Arey, Dave Ladret, Cameron Eckert Aklavik Hunters and Trappers Committee – Agnes Tardiff, Edward McLeod, Sam McLeod, Billy Archie Parks Canada – Ian McDonald, Seth Oldham, J-F. Bisaillon, Linh Nguyen Yukon Environment - Dorothy Cooley, Tom Jung Canadian Wildlife Service – Wendy Nixon Logistics Polar Continental Shelf Program; Aklak Air; Canadian Helicopters; Great Slave Helicopters; Northwright Aviation; Aurora Research Institute