Collapse of an insular bird species driven by a decrease in rainfall
Juan Carlos Illera1, David P Padilla2, Ángel C Moreno3
1Biodiversity Research Institute (CSIC-Oviedo University-Principality of Asturias), University of Oviedo, Campus of Mieres, E-33006 Mieres, Asturias, Spain.
The Science of the Total Environment
|December 5, 2024
Summary
Arid island bird populations have sharply declined due to extreme climate events and reduced rainfall, impacting their distribution and reproductive success. This highlights the vulnerability of unique island species to prolonged dry periods.
Area of Science:
- Ecology
- Conservation Biology
- Climate Change Science
Background:
- Arid island ecosystems host unique species adapted to harsh conditions.
- Anthropogenic climate change impacts on these fragile ecosystems are poorly understood.
- Endemic species face significant threats from extreme weather events.
Purpose of the Study:
- To evaluate the effects of extreme weather on an endemic bird species' population size, distribution, and habitat.
- To assess changes in population dynamics and habitat use over a 20-year period (2005-2024).
- To investigate the link between climatic changes, particularly rainfall patterns, and bird population health.
Main Methods:
- Utilized fine-grained field data and a distance-based sampling design.
- Employed habitat suitability modeling to analyze distribution and preferences.
- Compared data across two temporal windows (2005-2006 and 2024) to track changes.
Main Results:
- A sharp population decline of 63%-70% was observed between study periods.
- Species density decreased approximately threefold, with larger areas needed to find individuals.
- Population collapse correlated with decreased rainfall and drier years, impacting reproductive success.
Conclusions:
- Recurrent extreme climatic events significantly drive population declines in arid island bird species.
- Reduced rainfall and prolonged dry periods threaten the viability of unique island taxa.
- Conservation strategies must address climate change impacts on vulnerable island biodiversity.
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