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Résumé :
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Summer primary and secondary moult were investigated in four species of passerines, Northern Wheatear Oenanthe oenanthe, Black Redstart Phoenicurus ochruros, Linnet Linaria cannabina and Water Pipit Anthus spinoletta, in a mountain environment in central Italy. For each species we determined mean starting date and duration of both primary and secondary moults, and whether factors such as spring precipitation or temperature affected the timing or the duration of each moult. Northern Wheatear, the only long-distance migrant among the study species, was the first to start and to complete its moult. Furthermore, this species was the only one to moult earlier in years with warmer springs and with less snow, as predicted. Black Redstarts, on the other hand, started to moult later in warmer years, possibly because a greater proportion of pairs produced a second brood. In each of the species with distinguishable sexes, moult began later in females than in males. In Linnets, females finished primary moult on average two days earlier than males, due to a shorter moult duration. Similarly, Black Redstart females finished their secondary moult exactly at the same time as males, despite a later start.
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