Aliens Newsletter - ISSG

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30
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1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
Figure 8. Observations of Ruddy Ducks in Sweden, 1991-2009 (data for 2009 is provisional)
Numbers of Ruddy Ducks in other European countries
remain very low. In Belgium, one pair attempted
to breed in 2006 and 2007 (Wouter Fayvets pers.
comm.). In 2008, three pairs were recorded in a Special
Protection Area at Antwerp Harbour, and seven
young raised. Because of the presence of other
breeding waterbirds (most notably a Eurasian
Spoonbill Platalea leucorodia colony), the shooting
of these birds was not possible. Up to five pairs
were present in this area in May 2009 (Wouter
Fayvets pers. comm.) and two adult males, three
adult females and five pulli were shot in August
2009 (Hans van Gossum, pers. comm.). A small
number of birds (approximately 10-12) overwintered
in Belgium in 2009/10 so it appears likely that
there will be further breeding attempts in 2010.
Numbers in the Republic of Ireland appear to have
fallen, in line with the decline in the UK population,
and most records are now of single birds. Comprehensive
data from Morocco are difficult to obtain
but one possible Ruddy Duck x White-headed Duck
hybrid was reported near Rabat, with two Whiteheaded
Ducks, in April 2009 (Ana Iñigo in litt.). In
Germany, only one breeding pair has been recorded
since 2000 – in Lower Saxony in 2001 2002 and
2003 (Gerhard Adams pers. comm.). Although there
have been rare observations during the breeding season
in northwest Germany in more recent years, no
broods have been confirmed (Friederike Woog in
litt.). It is believed that only one Ruddy Duck has
been recorded in Iceland since 2004.
Conclusion
There is no doubt that the eradication of Ruddy Ducks
from the UK is a difficult task. However, progress
since the start of the eradication programme has been
in line with expectations, with numbers falling by
over 95% by March 2010. Ruddy Ducks have not become
harder to find or cull since the start of the programme,
nor have they abandoned traditional sites in
response to culling. One of the main areas of concern
now is the presence of Ruddy Ducks in other European
countries. Eradication in these areas, particularly
France and the Netherlands, must follow if the success
of the UK programme is not to be compromised.
The case of Ruddy Ducks can be seen as a test of
cross-border cooperation in the control non-natives,
and failure to act in other European countries may
jeopardize similar work which might be needed in the
future.
Acknowledgments
I would like to record my gratitude to all who have
assisted the programme by allowing access and providing
count data. Sincere thanks go to members of
the Project Advisory Group for their advice and support
over many years. Many thanks also to colleagues
in other European countries for data, most
notably Erik van Winden, Alain Caizergues, Wouter
Fayvets, Hans van Gossum, Mario Saénz de Buruaga
and Carlos Gutiérrez.
References
Central Science Laboratory (2002) UK Ruddy Duck
Control Trial Final Report www.defra.gov.uk
Green AJ, Hughes B (1996) Action plan for the
White-headed Duck Oxyura leucocephala. In:
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