7 research outputs found
Extreme events are more likely to affect the breeding success of lesser kestrels than average climate change
Climate change is predicted to severely impact interactions between prey, predators and habitats. In
Southern Europe, within the Mediterranean climate, herbaceous vegetation achieves its maximum
growth in middle spring followed by a three-month dry summer, limiting prey availability for
insectivorous birds. Lesser kestrels (Falco naumanni) breed in a time-window that matches the
nestling-rearing period with the peak abundance of grasshoppers and forecasted climate change may
impact reproductive success through changes in prey availability and abundance. We used Normalised
Difference Vegetation Index (NDVI) as a surrogate of habitat quality and prey availability to investigate
the impacts of forecasted climate change and extreme climatic events on lesser kestrel breeding
performance. First, using 14 years of data from 15 colonies in Southwestern Iberia, we linked fledging
success and climatic variables with NDVI, and secondly, based on these relationships and according
to climatic scenarios for 2050 and 2070, forecasted NDVI and fledging success. Finally, we evaluated
how fledging success was influenced by drought events since 2004. Despite predicting a decrease in
vegetation greenness in lesser kestrel foraging areas during spring, we found no impacts of predicted
gradual rise in temperature and decline in precipitation on their fledging success. Notwithstanding, we
found a decrease of 12% in offspring survival associated with drought events, suggesting that a higher
frequency of droughts might, in the future, jeopardize the recent recovery of the European population.
Here, we show that extreme events, such as droughts, can have more significant impacts on species
than gradual climatic changes, especially in regions like the Mediterranean Basin, a biodiversity and
climate change hotspotinfo:eu-repo/semantics/publishedVersio
Future climate change likely to reduce the Australian plague locust (Chortoicetes terminifera) seasonal outbreaks
© 2019 Elsevier B.V. Climate is a major limiting factor for insect distributions and it is expected that a changing climate will likely alter spatial patterns of pest outbreaks. The Australian plague locust (APL) Chortoicetes terminifera, is the most economically important locust species in Australia. Invasions cause large scale economic damage to agricultural crops and pastures. Understanding the regional-scale and long-term dynamics is a prerequisite to develop effective control and preventive management strategies. In this study, we used a 32-year locust survey database to uncover the relationship between historical bioclimatic variables and spatial seasonal outbreaks by developing two machine learning species distribution models (SDMs), random forest and boosted regression trees. The explanatory variables were ranked by contribution to the generated models. The bio-climate models were then projected into a future climate change scenario (RCP8.5) using downscaled 34 global climate models (GCMs) to assess how climate change may alter APL seasonal distribution patterns in eastern Australia. Our results show that the model for the distribution of spring outbreaks performed better than those for summer and autumn, based on statistical evaluation criteria. The spatial models of seasonal outbreaks indicate that the areas subject to APL outbreaks were likely to decrease in all seasons. Multi-GCM ensemble means show the largest decrease in area was for spring outbreaks, reduced by 93â94% by 2071â2090, while the area of summer outbreaks decreased by 78â90%, and 67â74% for autumn outbreaks. The bioclimatic variables could explain 78â98% outbreak areas change. This study represents an important step toward the assessment of the effects of the changing climate on locust outbreaks and can help inform future priorities for regional mitigation efforts in the context of global climate change in eastern Australia