18 research outputs found
Cascading effects of climate variability on the breeding success of an edge population of an apex predator
1. Large-scale environmental forces can influence biodiversity at different levels
of biological organization. Climate, in particular, is often associated with species
distributions and diversity gradients. However, its mechanistic link to population
dynamics is still poorly understood.
2. Here, we unravelled the full mechanistic path by which a climatic driver, the
Atlantic trade winds, determines the viability of a bird population.
3. We monitored the breeding population of Eleonora's falcons in the Canary
Islands for over a decade (2007â2017) and integrated different methods and
data to reconstruct how the availability of their prey (migratory birds) is regulated
by trade winds. We tracked foraging movements of breeding adults using
GPS, monitored departure of migratory birds using weather radar and simulated
their migration trajectories using an individual-based, spatially explicit
model.
4. We demonstrate that regional easterly winds regulate the flux of migratory birds
that is available to hunting falcons, determining food availability for their chicks
and consequent breeding success. By reconstructing how migratory birds are
pushed towards the Canary Islands by trade winds, we explain most of the variation
(up to 86%) in annual productivity for over a decade.
5. This study unequivocally illustrates how a climatic driver can influence local-scale
demographic processes while providing novel evidence of wind as a major determinant
of population fitness in a top predatorPeer reviewe