Aliens Newsletter - ISSG

Ruddy Ducks in Europe – the current situation
In order to completely remove the threat to the
White-headed Duck it will be necessary to eradicate
Ruddy Ducks throughout Europe and this will require
the co-operation of other European Governments.
In the last ten years the development of the
populations in Europe has been patchy, and now only
France, the Netherlands and possibly Belgium appear
to have viable populations. The Netherlands
had approximately 16–20 breeding pairs in 2008
(Erik van Winden pers. comm.) while France had
around 40–60 breeding pairs in 2007 (Alain Caizergues
pers. comm.). Ruddy Ducks in France are
concentrated in the northwest of the country and
120
100
80
60
40
20
0
numbers have continued to increase slowly, despite
around 100–150 birds being culled annually in recent
years. In the Netherlands, however, peak winter
counts have stabilised in recent years, with a peak
of approximately 85 birds in winter 2009/10. This
followed several years of significant increases (Fig.
7) and has occurred without any control of the population
in the Netherlands to date, suggesting that
there may be movement of birds between south-east
England and the Netherlands and that control of the
population in the UK has been responsible for the
slight decline in numbers. A similar link is suggested
by the rapid decline in the number of observations
of Ruddy Ducks in Sweden following the start
of the UK eradication programme in 2005 (Fig. 8).
73/74
75/76
77/78
79/80
81/82
83/84
85/86
87/88
89/90
91/92
93/94
95/96
97/98
99/00
01/02
03/04
05/06
07/08
09/10
Figure 7. Peak numbers of Ruddy Ducks in the Netherlands, 1973/74 to 2009/10 (data for winter 2009/10 is provisional)
22 29/2010