Abstract
Climate change can influence populations of monogamous species by
affecting pair-bond dynamics. This study examined the impact of climate
on widowhood and divorce, and the subsequent effects on individual vital
rates and life-history outcomes over 54 years in a snow petrel
(Pagodroma nivea) population. We found that environmental
conditions can affect pair-bond dynamics both directly and indirectly.
Divorce was adaptive, occurring more frequently after breeding failure
and leading to improved breeding success. Divorce probabilities also
increased under severe climatic conditions, regardless of prior breeding
success, supporting the ”Habitat-mediated” mechanisms. Generally,
pair-bond disruptions reduced subsequent vital rates and lifetime
outcomes. Climate forecasts from an Atmosphere-Ocean General Circulation
Model projected increased male widowhood rates due to decreased sea ice
negatively affecting female survival, despite considerable uncertainty.
These findings highlight the importance of environmentally induced
changes in demographic and pair-bond disruption rates as crucial factors
shaping demographic responses to climate change.