climate change article Flashcards
intro of article
Key Species Studied: Snowshoe hare (Lepus americanus) and its predators: Canada lynx (Lynx canadensis) and coyotes (Canis latrans).
Research Focus:
How climate change impacts predator-prey dynamics.
The role of snow conditions (depth and hardness) in altering predation risk.
Effects on cyclic dynamics in boreal forests.
Significance: Snowshoe hares are a keystone species, influencing boreal forest ecosystems through their population cycles.
Snow Conditions and Hare Mortality
Snow Depth:
Deep snow (>60 cm): Higher hare survival (30-day survival rate ~97%).
Shallow snow (<35 cm): Increased mortality (~80% survival rate, similar to cyclic decline phases).
Snow Hardness:
Shallow, soft snow: Increased coyote predation due to better mobility.
Deep, hard snow: Reduced risk overall but varied by predator.
Temperature: Ambient temperature had minimal impact on lynx predation but some qualitative reduction in risk was noted.
Predator Dynamics
Coyotes:
Higher foot-loading makes them less effective in deep snow.
Thrive in shallow snow conditions due to mobility advantages.
Lynx:
Well-adapted to hunt in a range of snow conditions.
Less impacted by snow depth or hardness compared to coyotes.
Hare foraging behaviour
Age-Specific Trends:
Sub-adults spent more time foraging (~10.8 hours/day) than adults (~10.1 hours/day).
Increased foraging in shallow snow correlated with higher predation risk.
Behavioral Response:
Similar reduction in foraging time in both shallow, soft snow and deep snow.
Mortality was higher in shallow snow, suggesting mobility constraints.
Implications of Climate Change
Shift in Predator-Prey Dynamics:
Reduced snow depth benefits coyotes, potentially disadvantaging lynx through competition.
Impact on Population Cycles:
Lower survival rates in shallow snow could dampen cyclic peaks of hare populations.
Broader Ecosystem Effects:
Reduced hare populations may cascade, affecting other boreal predators and the community structure.
Why do coyotes benefit from shallow snow?
A: Their high foot-loading is less disadvantageous in shallow snow, improving mobility and hunting success.
How does snow hardness influence predation risk?
A: Shallow, soft snow increases coyote predation risk, while deep, hard snow generally reduces predation.
How does snow depth influence predator-prey dynamics?
A: Reduced snow depth benefits generalist predators like coyotes and disadvantages lynx, altering their competitive balance.
What was the primary cause of hare mortality in shallow snow conditions?
A: Increased predation by coyotes.
How might climate change alter predator-prey dynamics in boreal forests?
A: Reduced snow cover favors generalist predators, leading to increased hare mortality and dampened population cycles.
What are the ecological consequences of diminished hare populations?
A: Potential cascading effects on predator populations and boreal forest community structure.
How can understanding snowshoe hare dynamics aid conservation efforts?
A: Predicting impacts of climate change on boreal ecosystems and managing predator-prey interactions.
