BLAGDON LAKE BIRDS

Ruddy Duck



Ruddy Duck Oxyura jamaicensis (Gmelin, 1789)

Ruddy Duck Oxyura jamaicensis jamaicensis.

(Scarce introduced resident & winter visitor. Formerly bred. All but eradicted.)

The record count of 603 was made on 17th January 1987, after Chew Valley Lake froze on the night of 16th January causing a major part of the flock to move to Blagdon, with many remaining into February.

Here is a chart of the regular winter WeBS counts made since 1961 with each winter presented as an average of the counts made from September to March inclusive, with the first winter period plotted against the x-axis viz. winter 1963-64 is shown against 1963 on the x-axis. I have superimposed the maximum counts.

At present I have no information for the period from 1973-79 when the WeBS data were only given as "present" with no counts published. I hope it may be possible to get this data in due course.

Why have numbers crashed? Well, as a non-native, Nearctic species that threatened the existence of the White-headed Duck Oxyura leucocephala, a cull has been carried out in the UK and Europe. The paper Control and Eradication of the North American Ruddy Duck in Europe gives more details. The cull began in earnest in 2005 and accounts for the drop in WeBS counts at Blagdon since then. The last breeding record was in 2006.

Bibliography (sources of information)

  1. Henderson, I. & Roberstson, P. Control and Eradication of the North American Ruddy Duck in Europe. Managing Vertebrate Invasive Species: Proceedings of an International Symposium (G. W. Witmer, W. C. Pitt, K. A. Fagerstone, Eds). USDA/APHIS/WS, National Wildlife Research Center, Fort Collins, CO. 2007.
  2. Henderson, I. Progress of the UK Ruddy Duck eradication programme. British Birds 102: 680–690. December 2009.
  3. Munoz-Fuentes, V., Vila, C., Green, A.J., Negro, J.J. & Sorenson, M.D. The ruddy duck Oxyura jamaicensis in Europe: natural colonization or human introduction? Molecular Ecology 15:6, 1441-1453. May 2006.
  4. Munoz-Fuentes, V., Vila, C., Green, A.J., Negro, J.J. & Sorenson, M.D. Hybridization between white-headed ducks and introduced ruddy ducks in Spain. Molecular Ecology 16:3, 629-638. February 2007.
  5. Taylor, S.M. (ed.). Avon Bird Report, 1987. Avon Ornithological Society.

Updated 14 December, 2013