The Primary Moult of Waders on the Atlantic Coast of Morocco

Abstract

Summary Data from 3659 waders of 23 species live‐trapped in the years 1971‐73 on the Atlantic coast of Morocco during the period of autumn moult and migration are analysed to estimate duration and timing of primary moult. Common Sandpiper was the only species to moult primaries in its first autumn (unless published ageing criteria are incorrect). Several species showed a low incidence of arrested primary moult and a higher incidence was observed in Ringed, Kentish and Grey Plovers. This is discussed in relation to breeding and migration. Similar rates of primary feather replacement relative to specific moult duration were observed in all species for which information was available. Comparisons between species and with published studies showed that variations in rate of moulting between species and between different geographical populations of the same species were largely due to differences in feather growth rate rather than in the numbers of primaries concurrently in growth. Variations in rate between individuals of the same population were achieved, at least in the first part of moult, by differences in feather dropping rate resulting in differences in the numbers of primaries growing concurrently. The timing and duration of moult in different populations and differences between breeding and non‐breeding components were closely related to the requirements of other annual cycle activities, notably breeding and migration. Non‐breeding birds summering in Morocco had started moult early. Locally breeding birds had an early start to a fairly slow moult which overlapped with breeding and which in some cases passed through an arrested stage. Birds breeding in cold temperate and arctic regions and wintering in Morocco moulted in a short time soon after arrival. In some cases, notably in Ringed Plovers, birds had commenced moulting on the breeding grounds and arrested moult during migration. Most Redshank and possibly Dunlin migrated in active wing moult. The fastest primary moult was achieved by high arctic breeding birds, Curlew Sandpiper and possibly Little Stint, which stopped to moult in Morocco before moving on to wintering areas further south. This situation is contrasted with that of populations of these two and other species wintering in the southern hemisphere where moult occurs over an extended period during the northern winter.

Pattern of Wing Moult and Its Relationship to Breeding in the Eurasian Stone-CurlewBurhinus oedicnemus

“…Cramp & Simmons 1983) and timing and duration of primary moult (e.g. Pienkowski et al 1976, Underhill 2003. Moreover, it seems likely that other factors, such as ecological (e.g.…”

Behaviour of young Ringed Plovers Charadrius hiaticula and its relationship to growth and survival to reproductive age

“…The return of birds to the breeding grounds at one year old is common in small waders, although the return tends to be delayed one or more years in larger species (e.g., Harris 1967, Johnson 1973, Glutz, Bauer & Bezzel 1975, Pienkowski et al 1976). This may imply some risk in breeding at one year, which is less in small birds (which may also have behaviour adpated to shorter lives).…”

Low asymmetry of primary moult in Dunlins Calidris alpina alpina migrating to wintering grounds

“…As both the flight feather moult and breeding are energy-demanding processes, the overlap between them is costly (Holmgren and Hedenström 1995;Hemborg and Lundberg 1998). Hence, such an overlap is quite rare, and in waders breeding in the Northern Hemisphere it has only been found in short-or medium-distance migrants (Pienkowski et al 1976;Walters 1984). Although a moult-breeding overlap leads to costs, it may also be an adaptive strategy (Barta et al 2006;Bridge 2006;Morales et al 2007).…”