Influence of snowmelt timing on the diet quality of pyrenean rock Ptarmigan (Lagopus muta pyrenaica): Implications for reproductive success
The Pyrenean rock ptarmigan (Lagopus muta pyrenaica) is the southernmost subspecies of the species in Europe and is considered threatened as a consequence of changes in landscape, human pressure, climate change, and low genetic diversity. Previous studies have shown a relationship between the date o...
Published in: | PLOS ONE |
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Main Authors: | , , , , |
Other Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Public Library of Science
2016
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Subjects: | |
Online Access: | http://hdl.handle.net/10261/128910 https://doi.org/10.1371/journal.pone.0148632 https://doi.org/10.13039/501100003339 https://doi.org/10.13039/501100000780 https://doi.org/10.13039/501100003329 |
Summary: | The Pyrenean rock ptarmigan (Lagopus muta pyrenaica) is the southernmost subspecies of the species in Europe and is considered threatened as a consequence of changes in landscape, human pressure, climate change, and low genetic diversity. Previous studies have shown a relationship between the date of snowmelt and reproductive success in the Pyrenean ptarmigan. It is well established that birds laying early in the breeding season have higher reproductive success, but the specific mechanism for this relationship is debated. We present an explicative model of the relationship between snowmelt date and breeding success mediated by food quality for grouse in alpine environments. From microhistological analyses of 121 faecal samples collected during three years in the Canigou Massif (Eastern Pyrenees), and the assessment of the chemical composition of the main dietary components, we estimated the potential quality of individual diets. Potential dietary quality was correlated with free-urate faecal N, a proxy of the digestible protein content ingested by ptarmigan, and both were correlated with phenological stage of consumed plants, which in turn depends on snowmelt date. Our findings suggest that the average snowmelt date is subject to a strong interannual variability influencing laying date. In years of early snowmelt, hens benefit from a longer period of high quality food resources potentially leading to a higher breeding success. On the contrary, in years of late snowmelt, hens begin their breeding period in poorer nutrient condition because the peaks of protein content of their main food items are delayed with respect to laying date, hence reducing breeding performance. We discuss the possible mismatch between breeding and snowmelt timing. This study was conducted under the framework of a contract between the Office National de la Chasse et de la Faune Sauvage (France) and Consejo Superior de Investigaciones Científicas (Spain). Additional funds were provided by RTA (Agricultural Technologies and Resources) ... |
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