TY - JOUR
T1 - The Canada Lynx (Lynx canadensis) of Isle Royale
T2 - Over-harvest, climate change, and the extirpation of an island population
AU - Licht, Daniel S.
AU - Moen, Ron A.
AU - Brown, D. Paul
AU - Romanski, Mark C.
AU - Gitzen, Robert A.
N1 - Publisher Copyright:
© 2015 The Canadian Field-Naturalist.
PY - 2015/4/1
Y1 - 2015/4/1
N2 - In the 1930s, the Canada Lynx (Lynx canadensis) was extirpated from Isle Royale, a 535-km2 island located in western Lake Superior, 22 km from the Ontario and Minnesota shorelines. The first half of the 20th century was a time of change on Isle Royale as Caribou (Rangifer tarandus) disappeared, Coyotes (Canis latrans) briefly appeared, Moose (Alces americanus), Grey wolves (Canis lupus), and Red Foxes (Vulpes vulpes) became established, and the habitat was altered by fire, logging, and over-browsing. although these changes may have contributed to the demise of the Canada Lynx, our results suggest that over-harvest was a primary cause. assuming a peak carrying capacity of 75 Canada Lynx and harvest rates comparable to those reported from 1890-1935, a population viability analysis indicated that the island population had a 0% chance of surviving 50 years. The analysis also indicated that, even in the absence of harvest, the population had only a 14% chance of persistence for 250 years. however, when 10 Canada Lynx were added to the modeled population every 10th year, the probability of persistence increased to 100%. Our analyses suggest that the island's Canada Lynx population maintained itself by periodic immigration across an ice bridge; therefore, natural recolonization should be possible. however, the probability of ice-bridge formation has declined from 0.8 in the winter of 1958-59 to 0.1 in 2012-13, likely as a result of climate change. The Isle Royale situation exemplifies another impact of climate change and the possible need to augment populations to mitigate the loss of connectivity.
AB - In the 1930s, the Canada Lynx (Lynx canadensis) was extirpated from Isle Royale, a 535-km2 island located in western Lake Superior, 22 km from the Ontario and Minnesota shorelines. The first half of the 20th century was a time of change on Isle Royale as Caribou (Rangifer tarandus) disappeared, Coyotes (Canis latrans) briefly appeared, Moose (Alces americanus), Grey wolves (Canis lupus), and Red Foxes (Vulpes vulpes) became established, and the habitat was altered by fire, logging, and over-browsing. although these changes may have contributed to the demise of the Canada Lynx, our results suggest that over-harvest was a primary cause. assuming a peak carrying capacity of 75 Canada Lynx and harvest rates comparable to those reported from 1890-1935, a population viability analysis indicated that the island population had a 0% chance of surviving 50 years. The analysis also indicated that, even in the absence of harvest, the population had only a 14% chance of persistence for 250 years. however, when 10 Canada Lynx were added to the modeled population every 10th year, the probability of persistence increased to 100%. Our analyses suggest that the island's Canada Lynx population maintained itself by periodic immigration across an ice bridge; therefore, natural recolonization should be possible. however, the probability of ice-bridge formation has declined from 0.8 in the winter of 1958-59 to 0.1 in 2012-13, likely as a result of climate change. The Isle Royale situation exemplifies another impact of climate change and the possible need to augment populations to mitigate the loss of connectivity.
KW - Canada Lynx
KW - Climate change
KW - Connectivity
KW - Island biogeography
KW - Isle Royale
KW - Lynx canadensis
KW - Metapopulation
KW - Over-harvest
KW - Population viability analysis
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UR - http://www.scopus.com/inward/citedby.url?scp=84938940519&partnerID=8YFLogxK
U2 - 10.22621/cfn.v129i2.1694
DO - 10.22621/cfn.v129i2.1694
M3 - Article
AN - SCOPUS:84938940519
SN - 0008-3550
VL - 129
SP - 139
EP - 151
JO - Canadian Field-Naturalist
JF - Canadian Field-Naturalist
IS - 2
ER -