Long-tailed Jaeger (Stercorarius longicaudus): vulnerability to climate change
Evidence for exposure
Potential changes in breeding habitat suitability:
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Current breeding area that is likely to become less suitable (95% of current range)
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Current breeding area that is likely to remain suitable (3%)
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Current breeding area that is likely to become more suitable (2%)
Current impacts to Long-tailed Jaegers attributed to climate change:
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Negative Impact: Southern populations are becoming less populous or going extinct in correlation with rising temperatures. Exact mechanism unknown, probably related to prey availability or heat stress.
Predicted changes in key prey species:
No key prey assessment was carried out for this species.
Climate change impacts outside of Europe
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Skuas have been heavily affected by climate change in Greenland, in particular due to lack of prey and increased predation due to other species prey-switching.
Sensitivity
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During the breeding season skuas are heavily reliant on a few species of lemmings and voles, and any impact to these species is likely to heavily affect skua breeding success.
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Long-tailed skuas populations are highly concentrated in the non-breeding season. >50% of global population congregate during migration in a relatively small area of the central Atlantic. Any negative change to this area is likely to have severe consequences on skua populations.
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Long-tailed jaeger chicks are highly vulnerable to predation by Arctic and red foxes (leading to up to 100% mortality in some years). Any changes in fox abundance (either negative or positive) may have severe impacts on long-tailed jaeger populations.
Adaptive capacity
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Skuas are very site-tenacious so any response to change is likely to be very slow, and range shifts in the short term are very unlikely.
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Long-tailed skuas will skip breeding in years with poor prey availability, which may be adaptive and maximises breeding output over time and help them cope with climate change. Long-tailed skuas are long-lived and several years of breeding failure or skipped breeding may not have a long-term impact on the population if populations are able to breed successfully in good years.
