Environmental Variability Shapes Life-History Trade-Offs Within and Between Populations of a Long-Lived Seabird

Area of Science:

• Ecology
• Evolutionary Biology
• Animal Behavior

Background:

• Organisms balance resource allocation between reproduction and self-maintenance, a trade-off influenced by environmental conditions.
• Long-lived species are expected to adopt conservative life-history strategies in unpredictable environments, but empirical data are scarce.

Purpose of the Study:

• To investigate how contrasting environmental conditions affect life-history strategies and reproductive senescence in black-browed albatross (Thalassarche melanophris) populations.
• To determine the relationship between environmental variability, life-history pace, and lifetime reproductive success.

Main Methods:

• Long-term monitoring of two black-browed albatross populations with differing environmental variability.
• Analysis of reproductive senescence patterns and their correlation with environmental conditions and lifetime reproductive success.

Main Results:

• Individuals in more variable environments exhibited slower life histories, characterized by late-onset senescence.
• Greater among-individual variation in life-history strategies was observed in variable environments.
• Earlier and faster reproductive senescence was linked to higher lifetime reproductive success, irrespective of environmental variability.

Conclusions:

• Environmental variability significantly shapes life-history strategies, favoring slower paces and increased individual variation in unpredictable conditions.
• The correlation between faster senescence and higher reproductive success suggests potential fitness benefits or accelerated aging post-reproduction.
• Findings offer insights into species' adaptive responses to increasing global environmental variability.