The moult of the Little Stint Calidris minuta in the Kenyan rift valley

Abstract

Moult data were collected during 1967–80 from some 6900 Little Stints in the southern Kenyan rift valley. Adults typically moulted from summer to winter body and head plumage during September and early October, soon after arrival. The complete pre‐winter wing and tail moult began in most adults between mid‐September and early October. Some birds finished by December, but others continued until February and March. Individual duration was usually between 100 and 150 days. Adults which completed this moult early often remoulted outer primaries between January and early April. Young birds acquired first‐winter body plumage during October and early November. Some 90% had a complete pre‐winter wing and tail moult. This usually began between December and early February, and finished during March or early April, taking about 70–100 days. In about 10% of young birds, flight feather moult was restricted to the outer primaries and inner secondaries. Birds adopting this strategy typically began moult late, during January or February. Short periods of suspension were common during pre‐winter wing moult, particularly in adults. The difference in moult speed between adult arid first‐winter birds was attributable in the primary, secondary and tail tracts to differences in numbers of growing feathers. Practically all birds completed a pre‐summer moult involving the entire body and head plumage, most of the tertials, some or all of the tail feathers and many wing coverts. Most birds began this moult between early February and late March, and finished between mid‐April and early May. It was typically later and more rapid in first‐year birds than adults. In late birds, the onset of pre‐summer moult was linked to the final stages of pre‐winter moult. The wing moult of the Little Stint in different wintering areas is discussed. First‐winter moult strategy is compared with that in other small Calidris species.

Conditions on the Non-Breeding Areas Affect Primary Moult Strategy of the Curlew SandpiperCalidris ferruginea

“…Based on the estimated start date of moult of P1, moult on average started about two months earlier in India (15 August) compared to Kenya (2 October). Our estimated start date of moult in Kenya was similar to the preliminary result presented by Pearson (1984) of adult Curlew Sandpipers at Lake Magadi. To the best of our knowledge, there are no prior estimates of moult start dates for Curlew Sandpipers in India to which we can compare our results, but in relation to the estimate start date of moult in the Grey Plover on 1 September (Balachandran et al 2000), Curlew Sandpipers started moult about two weeks earlier.…”

Replacement of Primaries during Prealternate Molt in North American Larus Gulls

“…The sequence of replacement of primaries during the prealternate molt in these and other species of Larus matches that during the second and later prebasic molts, starting at p1 and proceeding distally. This typical sequence differs from the sequence of replacement of primaries during the definitive prealternate molt documented in an Indigo Bunting (Passerina cyanea) and apparently some shorebirds (Pearson 1984, Marks 1993, Balachandran and Hussain 1998; cf. Wolfe and Pyle 2011).…”

The southern Jiangsu coast is a critical moulting site for Spoon-billed Sandpiper Calidris pygmaea and Nordmann’s Greenshank Tringa guttifer

“…The short moult duration of Little Stints in the Moroccan study was not conclusive, as only moult data during the early and middle moult stages were used for the moult duration estimates. In a separate study in the Kenyan rift valley (0.25-2.00˚S), the moult duration estimated for adult Little Stints was considerably longer at about four months (Pearson 1984). The moult duration for the Nordmann's Greenshank, on the other hand, is shorter than that estimated for the Common Greenshank at similar latitudes, which needed a total moult duration of 75 days (Pienkowski et al 1976).…”