Data from: Balancing moult, migration, and breeding in a long-lived partially migrant raptor
We analysed the timing and duration of moult using the models of Underhill and Zucchini (1988) and Underhill et al. (1990), implemented in the ‘moult’ package (Erni et al. 2013) for R (www.r-project.org). These models estimate moult duration, the average start date of moulting (from which the averag...
| Autores: | , , , , , , , , , , , , , , , , , , , |
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| Tipo de recurso: | conjunto de datos |
| Fecha de publicación: | 2026 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:dnet:digitalcsic_::4233dd0143856fb25504b5b32d45d588 |
| Acceso en línea: | http://hdl.handle.net/10261/432418 |
| Access Level: | acceso abierto |
| Palabra clave: | Biological sciences Egyptian vulture Moult extent Moult pattern Neophron percnopterus Symmetry index biology |
| Sumario: | We analysed the timing and duration of moult using the models of Underhill and Zucchini (1988) and Underhill et al. (1990), implemented in the ‘moult’ package (Erni et al. 2013) for R (www.r-project.org). These models estimate moult duration, the average start date of moulting (from which the average end date can be derived), and the standard deviation of the start date. We modelled primary moult of each subadult age class plumage scores against Julian day from 1 January of one year to 31 December of the following year (730 days), to account for the nearly two-year continuous moult cycle of these age classes (Fig. 1 and 2;~~~~ Supporting information). We modelled primary moult scores for adults against Julian day fromMarch onwards (365 days, one year). Adults also require two years to complete the moult, but in two non-continuous periods, and therefore, for adults we only considered the moult scores of one year. To determine the best way to code moult data, we conducted a preliminary analysis comparing five approaches (type of moult data arguments) in null models. The most parsimonious method (type 1; Supporting information; Erni et al. 2013) categorized individuals within the population as pre-moult, in-moult, or post-moult (Underhill and Zucchini, 1988) and has been previously applied to modelling moult scores in large raptors (Zuberogoitia et al. 2016). Moult scores were standardized as a ratio between 0 and 1 to run the analysis. We ran beta regression models using the ‘betareg’ package to analyse continuous variables bounded between 0 and 1, such as rates and proportions (Cribari-Neto and Zeileis 2010, Zeileis et al. 2012), to examine geographic differences in moulting patterns. We first analysed moult start and duration to test whether birds (adults and subadults) from the long-distance migratory Western European population start moulting later or have shorter moult duration than the sedentary Canary Islands subpopulation. Plumage (i.e. subadult age-classes) was included as a factor to test for age-related differences and we added subpopulation (Western Europe, Canary Islands) as an additional factor to compare these two groups. A separate analysis was performed for adults, including subpopulation as the only factor. We then extended both models by including all four subpopulations (Western Europe, Canary Islands, India, and Oman), excluding those with small sample sizes. |
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