Tringa nebularia – PIBYDD COESWERDD – Winter visitor and passage migrant
Typically, peak numbers of greenshank in Britain are recorded in August as birds move from their northern European (including Scottish) breeding sites to winter in south-west Europe and north and west Africa. The pattern seen in Pembrokeshire largely follows this regime, with generally higher numbers (usually 30-40, but over 70 in 1995 and 2005) seen in the July-September period compared with the November-February mid-winter period. (Note there were no migration period counts in the early 1990s).
Most of the birds have moved on by the end of October, but those remaining tend to stay put for the rest of the winter. This is generally around 20-30 birds although 58 were present in January 2019.
The Cleddau Estuary is of National Importance for its greenshank population, and is the second-most important Welsh site (the Burry Inlet has higher counts) for the species.
This map was produced by the West Wales Biodiversity Information Centre using data collected between November and February for the BTO Atlas 2007-11, with additional data collected in 2011-12 winter to fill gaps in coverage.
The main sites are:
- Nevern Estuary
- Almost anywhere on the Cleddau Estuary
Wetland Bird Survey
Maximum count may be usually in September-October, but in 2019-20 the highest numbers were in January and March.
Data for June and July are collected by Jane Hodges during the annual surveillance of summer shelduck populations on the Cleddau Estuary complex. There are no counts in August. The September to March data is collected from sites across Pembrokeshire (including the Teifi Estuary) for the BTO Wetland Bird Survey.
This graph will be updated as more counts come in
Pattern of occurrence
The June records are likely to be of failed breeders, returning south early. The main migration takes place from July to October. Birds arriving from October onwards are likely to stay the winter, moving on in March, back to (probably) their Scottish breeding grounds. Spring migration of birds that have wintered further south and will be breeding further north takes place in April-May.
Annie Haycock (BBS & WeBS local organiser)
HODGES J E. (2010-2020) Daugleddau Estuary and Milford Haven Waterway: annual surveillance of summer shelduck populations. Reports to the Milford Haven Waterway Environmental Surveillance Group.