| Title | Experimental nest cooling reveals dramatic effects of heatwaves on reproduction in a Mediterranean bird of prey |
| Abstract | Future climatic scenarios forecast increases in average temperatures as well as in the frequency, duration, and intensity of extreme events, such as heatwaves. Whereas behavioral adjustments can buffer direct physiological and fitness costs of exposure to excessive temperature in wild animals, these may prove more difficult during specific life stages when vagility is reduced (e.g., early developmental stages). By means of a nest cooling experiment, we tested the effects of extreme temperatures on different stages of reproduction in a cavity-nesting Mediterranean bird of prey, the lesser kestrel (Falco naumanni), facing a recent increase in the frequency of heatwaves during its breeding season. Nest temperature in a group of nest boxes placed on roof terraces was reduced by shading them from direct sunlight in 2 consecutive years (2021 and 2022). We then compared hatching failure, mortality, and nestling morphology between shaded and non-shaded (control) nest boxes. Nest temperature in control nest boxes was on average 3.9°C higher than in shaded ones during heatwaves, that is, spells of extreme air temperature (>37°C for >=2 consecutive days) which hit the study area during the nestling-rearing phase in both years. Hatching failure markedly increased with increasing nest temperature, rising above 50% when maximum nest temperatures exceeded 44°C. Nestlings from control nest boxes showed higher mortality during heatwaves (55% vs. 10% in shaded nest boxes) and those that survived further showed impaired morphological growth (body mass and skeletal size). Hence, heatwaves occurring during the breeding period can have both strong lethal and sublethal impacts on different components of avian reproduction, from egg hatching to nestling growth. More broadly, these findings suggest that the projected future increases of summer temperatures and heatwave frequency in the Mediterranean basin and elsewhere in temperate areas may threaten the local persistence of even relatively warm-adapted species. |
| Source | Global change biology (Print) 29 (19), pp. 5552–5567 |
| Keywords | early developmentextreme temperatureheat stressheatwavesnest microclimatetemperature manipulation |
| Journal | Global change biology (Print) |
| Editor | Blackwell Science., Oxford, Regno Unito |
| Year | 2023 |
| Type | Articolo in rivista |
| DOI | 10.1111/gcb.16888 |
| Authors | Corregidor-Castro, Alejandro; Morinay, Jennifer; McKinlay, Susan E.; Ramellini, Samuele; Assandri, Giacomo; Bazzi, Gaia; Glavaschi, Alexandra; De Capua, Enrico L.; Grapputo, Alessandro; Romano, Andrea; Morganti, Michelangelo; Cecere, Jacopo G.; Pilastro, Andrea; Rubolini, Diego |
| Text | 491721 2023 10.1111/gcb.16888 Scopus 2 s2.0 85165434434 early development extreme temperature heat stress heatwaves nest microclimate temperature manipulation Experimental nest cooling reveals dramatic effects of heatwaves on reproduction in a Mediterranean bird of prey Corregidor Castro, Alejandro; Morinay, Jennifer; McKinlay, Susan E.; Ramellini, Samuele; Assandri, Giacomo; Bazzi, Gaia; Glavaschi, Alexandra; De Capua, Enrico L.; Grapputo, Alessandro; Romano, Andrea; Morganti, Michelangelo; Cecere, Jacopo G.; Pilastro, Andrea; Rubolini, Diego Italian Institute for Environmental Protection and Research; Istituto di Ricerca sulle Acque, Italy; Universita degli Studi di Milano; Norges Teknisk Naturvitenskapelige Universitet; Universita degli Studi di Torino; Universita degli Studi di Padova; National Biodiversity Future Center; Provincia di Matera Parco della Murgia Materana Future climatic scenarios forecast increases in average temperatures as well as in the frequency, duration, and intensity of extreme events, such as heatwaves. Whereas behavioral adjustments can buffer direct physiological and fitness costs of exposure to excessive temperature in wild animals, these may prove more difficult during specific life stages when vagility is reduced e.g., early developmental stages . By means of a nest cooling experiment, we tested the effects of extreme temperatures on different stages of reproduction in a cavity nesting Mediterranean bird of prey, the lesser kestrel Falco naumanni , facing a recent increase in the frequency of heatwaves during its breeding season. Nest temperature in a group of nest boxes placed on roof terraces was reduced by shading them from direct sunlight in 2 consecutive years 2021 and 2022 . We then compared hatching failure, mortality, and nestling morphology between shaded and non shaded control nest boxes. Nest temperature in control nest boxes was on average 3.9°C higher than in shaded ones during heatwaves, that is, spells of extreme air temperature >37°C for >=2 consecutive days which hit the study area during the nestling rearing phase in both years. Hatching failure markedly increased with increasing nest temperature, rising above 50% when maximum nest temperatures exceeded 44°C. Nestlings from control nest boxes showed higher mortality during heatwaves 55% vs. 10% in shaded nest boxes and those that survived further showed impaired morphological growth body mass and skeletal size . Hence, heatwaves occurring during the breeding period can have both strong lethal and sublethal impacts on different components of avian reproduction, from egg hatching to nestling growth. More broadly, these findings suggest that the projected future increases of summer temperatures and heatwave frequency in the Mediterranean basin and elsewhere in temperate areas may threaten the local persistence of even relatively warm adapted species. 29 Published version http //www.scopus.com/record/display.url eid=2 s2.0 85165434434 origin=inward Articolo in rivista Blackwell Science. 1354 1013 Global change biology Print Global change biology Print Glob. chang. biol. Print RUBOLINI DIEGO CORREGIDOR CASTRO ALEJANDRO michelangelo.morganti MORGANTI MICHELANGELO |
