Laysan Albatross (Phoebastria immutabilis) and the closely-related Black-footed Albatross (P. nigripes) replace 20%–90% of their 35–41 wing flight feathers every year. Large-scale molt patterns (patterns between rather than within molt series) account for 77% of the variation in the number of flight feathers replaced. We identified four molt series: series A—the five outer primaries; series B—the five inner primaries plus four outer secondaries; series C—the middle secondaries; and series D—the inner secondaries. A fifth molt series may lie between series C and D. Each year, series A and D initiate molt, but series B and C may or may not initiate molt. The result is four “annual molt patterns”: ABCD, ABD, ACD, and AD. Temporally overlapping waves of molt never occur within series A or B, but about one third of the time they occur within series C and D. Multiple, spatially defined waves of molt (replaced feathers separated by unreplaced feathers) never occur within series A, but occur about two thirds of the time within series B, C, and D. The inner primaries and outer secondaries constitute a single molt series, probably to equilibrate between series total feather length, and thus, total molt duration. Studies of foraging range and reproduction in albatrosses would benefit from the development of species-specific indices of molt duration and extent that are biologically as well as statistically defensible. The number of outer primary feathers replaced and the number of molt series that activate molt are two such indices for Laysan and Black-footed Albatrosses.
There is great variation in discarding practice among fisheries in different parts of the world. Management systems result in some fisheries discarding mostly fish offal, much of which is macerated into small chunks, while other fisheries discard large (ca. 25 cm) whole fish. Scavenging seabirds consume high proportions of most categories of discarded fish and offal (typically 60 to 80% of discarded roundfish, 70 to 95% of discarded offal), but tend to avoid discarded benthic invertebrates and fish that are difficult to swallow, such as species with long spines or large flatfish. Amounts and composition of fishery discards and offal reaching benthic scavenging communities are clearly very strongly influenced by the intense but selective consumption by seabirds, and this alteration will depend strongly on details of the fishery management regulations and customs, such as whether or not waste is macerated. There is scope to adjust fisheries management practices to reduce the impact of offal and discards on scavenger communities.
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