Anna L K Nilsson1,2, Thomas Skaugen3, Trond Reitan4,3, Jan Henning L'Abée-Lund3, Marlène Gamelon5, Kurt Jerstad6, Ole Wiggo Røstad7, Tore Slagsvold4, Nils C Stenseth4, L Asbjørn Vøllestad4, Bjørn Walseng8. 1. Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, P. O. Box 1066, Blindern, 0316, Oslo, Norway. anna.nilsson@nina.no. 2. Norwegian Institute for Nature Research, Thormøhlens Gate 55, 5006, Bergen, Norway. anna.nilsson@nina.no. 3. Norwegian Water Resource and Energy Directorate, P. O. Box 5091, Majorstua, 0301, Oslo, Norway. 4. Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, P. O. Box 1066, Blindern, 0316, Oslo, Norway. 5. Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, 7491, Trondheim, Norway. 6. Jerstad Viltforvaltning, Aurebekksveien 61, 4516, Mandal, Norway. 7. Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, NMBU, 1432, Ås, Norway. 8. Norwegian Institute for Nature Research, Gaustadallén 21, 0349, Oslo, Norway.
Abstract
BACKGROUND: Earlier breeding is one of the strongest responses to global change in birds and is a key factor determining reproductive success. In most studies of climate effects, the focus has been on large-scale environmental indices or temperature averaged over large geographical areas, neglecting that animals are affected by the local conditions in their home ranges. In riverine ecosystems, climate change is altering the flow regime, in addition to changes resulting from the increasing demand for renewable and clean hydropower. Together with increasing temperatures, this can lead to shifts in the time window available for successful breeding of birds associated with the riverine habitat. Here, we investigated specifically how the environmental conditions at the territory level influence timing of breeding in a passerine bird with an aquatic lifestyle, the white-throated dipper Cinclus cinclus. We relate daily river discharge and other important hydrological parameters, to a long-term dataset of breeding phenology (1978-2015) in a natural river system. RESULTS: Dippers bred earlier when winter river discharge and groundwater levels in the weeks prior to breeding were high, and when there was little snow in the catchment area. Breeding was also earlier at lower altitudes, although the effect dramatically declined over the period. This suggests that territories at higher altitudes had more open water in winter later in the study period, which permitted early breeding also here. Unexpectedly, the largest effect inducing earlier breeding time was territory river discharge during the winter months and not immediately prior to breeding. The territory river discharge also increased during the study period. CONCLUSIONS: The observed earlier breeding can thus be interpreted as a response to climate change. Measuring environmental variation at the scale of the territory thus provides detailed information about the interactions between organisms and the abiotic environment.
BACKGROUND: Earlier breeding is one of the strongest responses to global change in birds and is a key factor determining reproductive success. In most studies of climate effects, the focus has been on large-scale environmental indices or temperature averaged over large geographical areas, neglecting that animals are affected by the local conditions in their home ranges. In riverine ecosystems, climate change is altering the flow regime, in addition to changes resulting from the increasing demand for renewable and clean hydropower. Together with increasing temperatures, this can lead to shifts in the time window available for successful breeding of birds associated with the riverine habitat. Here, we investigated specifically how the environmental conditions at the territory level influence timing of breeding in a passerine bird with an aquatic lifestyle, the white-throated dipperCinclus cinclus. We relate daily river discharge and other important hydrological parameters, to a long-term dataset of breeding phenology (1978-2015) in a natural river system. RESULTS: Dippers bred earlier when winter river discharge and groundwater levels in the weeks prior to breeding were high, and when there was little snow in the catchment area. Breeding was also earlier at lower altitudes, although the effect dramatically declined over the period. This suggests that territories at higher altitudes had more open water in winter later in the study period, which permitted early breeding also here. Unexpectedly, the largest effect inducing earlier breeding time was territory river discharge during the winter months and not immediately prior to breeding. The territory river discharge also increased during the study period. CONCLUSIONS: The observed earlier breeding can thus be interpreted as a response to climate change. Measuring environmental variation at the scale of the territory thus provides detailed information about the interactions between organisms and the abiotic environment.
Authors: Marlène Gamelon; Jarle Tufto; Anna L K Nilsson; Kurt Jerstad; Ole W Røstad; Nils C Stenseth; Bernt-Erik Saether Journal: Evolution Date: 2018-10-09 Impact factor: 3.694
Authors: Amy E Hinks; Ella F Cole; Katherine J Daniels; Teddy A Wilkin; Shinichi Nakagawa; Ben C Sheldon Journal: Am Nat Date: 2015-05-05 Impact factor: 3.926
Authors: Javier Balbontín; Ignacio G Hermosell; Alfonso Marzal; Maribel Reviriego; Florentino De Lope; Anders Pape Møller Journal: J Anim Ecol Date: 2007-09 Impact factor: 5.091
Authors: Marlène Gamelon; Vidar Grøtan; Anna L K Nilsson; Steinar Engen; James W Hurrell; Kurt Jerstad; Adam S Phillips; Ole W Røstad; Tore Slagsvold; Bjørn Walseng; Nils C Stenseth; Bernt-Erik Sæther Journal: Sci Adv Date: 2017-02-01 Impact factor: 14.136