Balancing moult, migration, and breeding in a long-lived partially migrant raptor

Moult, breeding, and migration are the three major life-history events in the annual cycle of birds. All are energetically demanding processes that rarely overlap. In large raptors such as the Egyptian vulture Neophron percnopterus, completing a full moult may take more than one year, requiring birds to balance this process with other life-cycle events. We analysed 740 moult cards from across the species’ distribution, including migratory, sedentary, and mixed subpopulations, to test predictions about trade-offs between the physiological demands of migration and moult. Juveniles began moulting in January-February of their second calendar year and continued \"year-round\" until their fifth calendar year. Adults, however, suspended moult from the months preceding spring migration until the late breeding phase. Subadults from the Canary Islands started moulting earlier and completed it faster than those from Western Europe, while adults from Western Europe initiated moult later than adults f..., We created moult cards from high-definition and high-quality pictures (sufficient to compare feather wear and changes in tone and colour) of wild birds taken by research teams during trapping events (n = 265), wildlife photographers (n = 251), and two online citizen science repositories, the Macaulay Library (www.macaulaylibrary.org/) and iNaturalist (www. inaturalist.org/) (n = 81 and 143, respectively) (moult_EV_Raw_Database.csv). To avoid pseudoreplication, data on single individuals from different sources were not used, although we used different pictures of the same individual to cross-check the moult cards. In the few cases where individuals from the same area were selected, individual marks and moult state were checked to avoid resampling of the same bird. Scoring and recording moult on cards for all photographs was conducted by a single, trained researcher (IZ, see Zuberogoitia et al. 2013). Birds in hand were photographed with extended wings (normally taking two photos per wing..., # Data from: Balancing moult, migration, and breeding in a long-lived partially migrant raptor

Dataset DOI: [10.5061/dryad.c2fqz61qt](https://doi.org/10.5061/dryad.c2fqz61qt)

## Description of the data and file structure

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](http://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 day..., ,