Climate change increases reproductive failure in Magellanic penguins

Area of Science:

• Ecology
• Climate Change Biology
• Ornithology

Background:

• Climate change is increasing the frequency and intensity of extreme weather events globally.
• Rising rainfall and changing temperatures are observed near Punta Tombo, Argentina, a key Magellanic penguin breeding site.
• Magellanic penguin (Spheniscus magellanicus) populations face potential threats from altered weather patterns.

Purpose of the Study:

• To investigate the impact of weather, specifically rainfall and storms, on the survival rates of Magellanic penguin chicks.
• To determine the relationship between storm-induced mortality and other causes of death like starvation and predation.
• To assess how climate variability and changes in nesting behavior affect overall reproductive success in Magellanic penguins.

Main Methods:

• Long-term monitoring (1983-2010) of 3496 known-age Magellanic penguin chicks at Punta Tombo.
• Analysis of mortality causes, correlating chick deaths with specific weather events (rainfall, temperature, storms).
• Statistical analysis to examine the relationship between storm mortality, starvation, predation, and fledging success, considering nesting types and egg-laying synchrony.

Main Results:

• Extreme rainfall events were a significant cause of chick mortality in certain years, killing up to 50% of chicks.
• Storm mortality was additive, not directly linked to starvation or predation rates, but negatively impacted fledging success.
• Higher rainfall and lower temperatures increased chick deaths, with younger chicks (9-23 days) most vulnerable to storms; heat affected older chicks (up to 70 days).
• Burrow nesting provided some protection against storm-related mortality.
• Decreased egg-laying synchrony has lengthened the period of chick vulnerability to adverse weather.

Conclusions:

• Increased storm frequency and intensity due to climate change are causing significant reproductive failure in Magellanic penguins.
• The findings suggest that climate variability is undermining the resilience of this species and likely others in the region.
• Conservation strategies may need to account for increased weather-related risks to breeding success.