Verkuil et al. 2006 Ibis Broad-billed Sandpipers

Ibis, 2006

We studied phenology, staging time and refuelling in Broad-billed Sandpipers Limicola falcinellus stopping over during spring migration in the Sivash (Black Sea, Ukraine) in May 1991–94. In the study area, peak staging numbers of 2000–2500 individuals occurred in the third week of May. In May 1993, 460 birds were marked with a yellow dye and 126 of these were colour-ringed. Before 28 May no departure of birds dyed yellow could be detected; by 3 June all birds had departed. Colour-ringed adults in mid May 1993 staged for a minimum of 8.2 days. After the observed departure of large flocks (24 May and later) the staging time of colour-ringed birds decreased significantly with body mass at the time of capture. Of birds mist-netted in 1991–94, 99.3% were in full summer plumage and 89% were adults. In second-year birds, fuel deposition rate (measured between individuals) was 0.44 g/day. In adults caught from early May to 24 May, overall fuel deposition rate was 1.04 g/day (3.4% of lean body mass). Mean adult body mass in early May was 34.8 g, increasing to 45.5 g after 24 May. Estimated body mass at departure was 51 g. Departure body mass and flight range estimates suggest that although birds refuelled quickly, fuel loads are only just sufficient for an unbroken flight to Scandinavia and the Kola Peninsula. We suggest that Broad-billed Sandpipers use the Sivash as a crucial final take-off stopover site, and that they follow a ‘jumping’ migration strategy, performed under narrow time constraints.

During May 1992 the spring migration of the Broad-billed Sandpiper in the Sivash, Ukraine, was studied. The numbers increased rapidly from some tens early May up to an estimated 6,000 in the last ten days of May. The birds preferred mudflats in the eastern part of the area which proved to be rich in benthic fauna. In the central Sivash, lower numbers were found and only pelagic prey was available. The Sivash can be considered as one of the most important stop-over sites for the Broad-billed Sandpiper during spring migration, for at least 30% of the European population was found to be present.

1998

Acta Ornithologica, 2010

Wood Sandpipers are generally known to follow a time-minimization migration strategy on their autumn passage. We investigated whether the migration strategy adopted by first-year Wood Sandpipers is susceptible to temporal variations. Wood Sandpipers were trapped during the July-September period from 1997 to 2007 at the Jeziorsko reservoir, central Poland. Intra-and inter-seasonal variation in stopover length, refuelling rates, departure fat loads and flight range were investigated. There was a constant decline in the refuelling rates over the course of the migratory season, reaching 0.55 g/day at the end of August. Such low refuelling rates are considered typical of energy-minimizers.

Condor, 2006

We examined differential migration in the Western Sandpiper (Calidris mauri) with respect to body size and wing chord allometry within sex and age categories. Culmen and wing chord data were collected as indices of structural body size at three sites that vary latitudinally: Ecuador, Panama, and Mexico. Within all sex and age categories, larger individuals (i.e., those with longer culmens and wing chords) and those with a disproportionately longer wing chord relative to the culmen migrated farther south. Our results, coupled with known molting schedules, indicate that i) immature sandpipers that grow disproportionately longer primary feathers on breeding grounds migrate farther during their first southward migration, and ii) adults that fly farther grow disproportionately longer primary feathers on the nonbreeding grounds. Although no single-factor hypothesis accounts for all aspects of age, sex, and size of Western Sandpiper distributions, costs associated with flight during migration play a significant role in determining differential nonbreeding latitudinal distributions.

2006

Journal of Avian Biology, 2005

The propensity of migratory waders to remain on the non-breeding grounds during the arctic breeding season (''oversummer'') in their first biological year of life (''juveniles'') may be latitude, and thus migratory distance dependent. We compared the extent of preparation for northward migration of western sandpipers Calidris mauri spending the non-breeding season in México and Panamá during 1995 Á/1998. During winter residency and premigratory periods, we measured body mass and scored the extent of dull basic versus bright alternate breeding plumage of captured juveniles and adults (second biological year or older), and obtained additional plumage scores from observations of uniquely colour banded birds. Nearly all western sandpipers in México prepared for northward migration by increasing body mass and moulting into breeding plumage. In Panamá, most adults prepared for migration, but few, if any, juveniles did so. Patterns of body mass and breeding plumage development do not generally support the hypothesis that oversummering by juveniles results directly from less efficient foraging or from resource competition with adults. We suggest instead that costs directly associated with migratory distance per se influence the life history strategies of sandpipers spending the non-breeding seasons at different latitudes. This latitudinal difference should interact with the well documented sex-ratio cline in non-breeding distribution (male western sandpipers predominating in northern parts of the range and females in southern parts). This suggests that females have more conservative life histories, prioritizing first year survivorship, relative to males that instead weight firstyear breeding opportunities.

Bulletin 110 …, 2006

In spring, large numbers of migrating Broad-billed Sandpipers make a stop-over in the Sivash, a shallow lagoon system in the Crimea, Ukraine, between the Black Sea and the Sea of Azov. Observed fuelling rates are high and, in just a few weeks, the birds can build up sufficient departure mass to reach their breeding grounds in a single non-stop flight (Verkuil et al. 2006). For feeding, Broad-billed Sandpipers prefer the brackish lagoons with a diverse benthic prey community. They ignore the hypersaline lagoons which are teeming with brine shrimp (Artemia sp.), a common prey for migrating Dunlins and Curlew Sandpipers in this area (Verkuil et al. 2003). In this paper we report on diet choice in relation to gut processing efficiency of different possible prey species for Broad-billed Sandpipers. We ask two questions: “Why do Broad-billed Sandpipers avoid feeding on brine shrimp in the hypersaline lagoons?” and “Do they specialize on one particular prey species in the brackish lagoons?”. Digestion efficiency of birds fed with brine shrimp was lower than for birds fed with the polychaete Nereis diversicolor or the crustacean Gammarus insensibilis. In the brackish lagoons, prey items seen ingested were both polychaetes (Nereis diversicolor) and larger crustaceans. Field observations on defecation intervals compared with identical observations on captive individuals suggest that both polychaetes and crustaceans were included in the diet. Although studies from other staging and wintering sites report that Broad-billed Sandpiper usually eat polychaetes, we suggest that they optimize their energy intake by eating a multi-course meal.

Journal of Avian Biology, 2002

Wolf, N. 2002. Trade-offs, condition dependence and stopover site selection by migrating sandpipers. -J. Avian Biol. 33: 47 -55.