Anas platyrhynchos – HWYADEN WYLLT – Breeding resident, passage migrant and winter visitor
Mallard can be seen at any time of year in Pembrokeshire, however, numbers in autumn and winter are augmented by arrivals from north-east Europe and Russia (based on ringing recoveries from Orielton and throughout Wales). Numbers are also increased by the release of birds for shooting, and it is possible the variability of this source accounts for much of the variability of the annual maxima recorded by the Wetland Bird Survey locally.
In the UK as a whole, numbers of (wild) mallard increased in the 1970s and 1980s, but have subsequently fallen. There is no clear reason for the decline, but there is a clear relationship with the ingestion of lead shot. Ringing recoveries have also shown that there is a reduction in the number of winter visitors from continental Europe (Birds of Wales)- probably due to a combination of less severe winters and a reduction in shooting pressure there.
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.
Wetland Bird Survey
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.
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.
PRITCHARD R, HUGHES J, SPENCE I.M., HAYCOCK R.J. & BRENCHLEY A. (Editors) (2021) Birds of Wales. Liverpool University Press