The role of nest temperature in shaping parental care and sibling rivalry in the lesser kestrel (Falco naumanni)

Climate change is a major driver of biodiversity loss, altering ecosystems and species interactions at an accelerating pace. Birds, which are highly adaptable but physiologically sensitive organisms, are particularly vulnerable to rising temperatures and shifting climatic patterns. Their breeding success, survival rates, and behavioral strategies are closely associated with environmental conditions, making them key indicators of the ecosystem health. As global temperatures increase due to anthropogenic activities such as greenhouse gas emissions, deforestation, and habitat destruction, many bird species face challenges related to thermoregulation, food availability, and habitat loss. One of the most critical ways in which climate change affects avian populations is through its impact on reproduction. High temperatures can disrupt nesting conditions, influence parental investment, and alter chick development. Nest-bound chicks, in particular, are exposed to thermal stress, which can affect their growth, survival, and interactions with siblings. In species that rely on parental care, heat stress may influence feeding rates and competitive behaviors among nestlings, potentially modifying survival outcomes. This study focuses on the lesser kestrel (Falco naumanni), a colonial and cavity-nesting raptor, to examine the potential effects of increasing nest temperatures on feeding behavior and sibling competition. By analysing behavioral responses under different thermal conditions, we aim to understand how climate-induced changes may impact birds’ lives, reproductive strategies and parental care. With extreme weather events and rising temperatures continuing to intensify, studying how birds respond to these environmental challenges could be useful for successful biodiversity conservation. Research in this field can provide information on how to limit the negative effects of climate change and how to ensure the survival of vulnerable bird populations in the future.