Regional, seasonal and annual variations in the structure of Purple Sandpiper Calidris maritime populations in Britain

Abstract

Samples of Purple Sandpipers were captured around the coasts of Britain. Analysis of their bill‐length distributions enabled the sex ratios and percentages of ‘long‐billed’ and ‘short‐billed’ birds at each locality to be estimated. The sex ratio for the ‘long‐billed’ population was estimated to be one female to 2–11 males, and one female to 1 ‐34 males for the ‘short‐billed’ population. During winter, proportionately more ‘long‐billed’ birds occurred in northern and western Scotland, Wales and southern England, whilst ‘short‐billed’ birds predominated from Kincardine to Yorkshire. The total sizes of the ‘long‐’ and ‘short‐billed7’ populations were c. 15 000 and 4000, respectively. ‘Short‐billed’ birds started arriving from Norway in early July. ‘Long‐billed’ birds did not arrive until late October. Their origins are as yet unknown. No annual variations in the population structure were detected.

Population structure of Purple Sandpipers (Calidris maritima) as revealed by mitochondrial DNA and microsatellites

“…Migratory routes between breeding and wintering sites of North American Purple Sandpipers were largely unknown until a recent study confirmed a trans‐Atlantic route from the Canadian Arctic in the summer to Scotland and Ireland in the winter (Summers et al., ). Wintering aggregations of Purple Sandpipers may contain birds from multiple breeding locations (Corse & Summers, ; Nicoll, Summers, Underhill, Brockie, & Rae, ). For example, the majority of Svalbard breeders migrate to the Norwegian coast and western Sweden (Hake, Blomqvist, Pierce, Järås, & Johansson, ), but small numbers winter in northeast Scotland (Summers et al., ) where they mix with individuals from Canada (Summers et al., ).…”

Sex-specific migration patterns and population trends of SkylarksAlauda arvensisringed during autumn migration in southern Italy

“…In order to separate males from females, we used measurements proposed by Scebba (2001Scebba ( , 2009) based on a discriminant analysis of wing length. Frequency distributions of wing length were analysed using Harding-Cassie plots on arithmetic probability paper (Harding 1949, Cassie 1954, Griffiths 1968, Nicoll et al 1988, a graphical method for separating superimposed normal distributions. This analysis was based on the assumption that wing lengths of Skylark populations migrating along the southern Tyrrhenian coastline would be normally distributed.…”

Sex ratios of waders at the northern end of the East Atlantic flyway in winter

“…Circles -sexed on bill length, squares -sexed on gonads, triangles -molecularly sexed. The data were from this study, Belopolski (1941), Nicoll et al (1988), Summers et al (1990b), Hake et al (1997), Mittelhauser et al (2006), Strann & Summers (2006), Summers (2007), Foster et al (2010), Hallgrimsson et al (2011) and Guyonnet et al (2011).…”