Taxonomy

Oxyura jamaicensis | Ruddy Duck | Lacha rua

Distribution

Status

Conservation status

Least Concern

Legal status

In the Republic of Ireland the Ruddy Duck is protected during its breeding season (breeding birds, nests and eggs). There is however an open season in which you can hunt Ruddy from 1st September to the 31st of January.

Listed as a schedule 9 species under Articles 15 & 15A of the Wildlife Order (Northern Ireland) 1985 (Article 15A not yet enacted).

Regulated invasive  species of Union concern under the European Regulation on the prevention and management of the introduction and spread of invasive alien species [1143/2014].

First reported in the wild

1973

Invasiveness

Invasive species - risk of High Impact

Irish status

Established

Introduction pathways - 1

Unaided

Introduction pathways subclass - 1

Natural dispersal across borders of invasive aliens

Invasive score

18

NAPRA Ireland risk assessed

No

Species Biology

Identification

"Oxyura jamaicensis (ruddy duck) is a small diving duck with a long tail, often held erect. On an average the females weigh 550g and males around 600g. During the breeding season males can be distinguished from other ducks by a white cheek patch, chestnut red body plumage, and blue bill. Females are distinguished by their body structure and off-white cheek split by a horizontal brown stripe. Both sexes can be distinguished from the white-headed duck by their smaller size, shorter tail, thinner cheek stripe and concave bill profile." (Hughes, 2005).

Ecology

Ruddy ducks feed on benthic invertebrates, especially chironomid larvae (Hughes, 2005) and may compete with tufted ducks for food (Lever, 2009). May compete with grebes for nesting space and engage in aggressive interactions during the breeding season (Lever, 2009). The main threat and impact of Ruddy ducks in Europe is the hybridised with the endangered white headed duck (Oxyura leucocephala), in Spain (Munoz-Fuentes, 2006).

Habitat

Inland surface waters

Reproduction

Breeding strategy is a mixture of monogamy, polygyny and promiscuity, ruddy ducks can relay up to 4 times per season if eggs are lost but there is usually only one brood per year (2-3 young per female per year) (Hughes, 2005).

Pathway and vector description

All ruddy ducks in Europe descend from a founder population of approximately 7 individuals brought to the UK in 1948 (Munoz-Fuentes et al., 2006). From there they have dispersed naturally across Europe, as far north as Iceland (Hughes, 2005).

Mechanism of impact

Hybridisation

Management approach

The main method used in the UK eradication programme was shooting, which was by far the most effective. Nest trapping and egg oiling, while much less efficient were appropriate at some sites (Cosgrove et al., 2008).

Shooting

This method allows the cull of a substantial proportion of the population when the large wintering flocks are targeted (Cosgrove et al., 2008; Henderson, 2009). Either rifles equipped with sound-moderators (silencers) or shotguns are used. Focussing on the main breeding sites during the breeding season prevents population rises by minimising the number of young hatched (Henderson, 2006). This is most effective early in the breeding season when there is less cover and the females aren’t sitting on nests (Henderson, 2006). Generally, birds are herded by boat towards the guns on the banks (during the breeding season) or are shot from the boat (winter) (Henderson, 2006) as they fly overhead.

Broad environment

Terrestrial

Habitat description

Found in freshwater habitats, outside of the breeding season prefer habitats with emergent vegetation (Lever, 2009).

Species group

Vertebrate

Native region

North America

Distribution

World distribution(GBIF)

Irish distribution

Established - Localised. Population for Ireland is almost certainly less than 150, though exact numbers and distribution are unknown (Lever, 2009).

Native distribution

Native to North America and the Caribbean and having been introduced to Britain, now occurs in Europe, from Scandanavia as far south as Algeria in North Africa (Hughes, 2005).. Population in Europe in 2013 is thought to be less than 7% of the 2000 level due to an international plan to eradicate the species from Europe (Robertson et al., 2015). 

Temporal change

Date of first record category

1971-1980

Fifty year date category

1951-2000

Records submitted to Data Centre in 2017

The following map is interactive. If you would prefer to view it full screen then click here.

How can you help

Report any sightings to the National Biodiversity Data Centre.

Further information

Delivering Alien Invasive Species In Europe (DAISIE) project list this as one of the 100 Worst Invaders in Europe. The British population of ruddy ducks was formerly the main source of the European population and a control programs have been in place in the UK since 2006 (Henderson, 2006) and it is now thought to contain less than 30% of the total European population (Robertson et al., 2015).

During the breeding season, ruddy ducks can be extremely aggressive towards other animals, including rabbits, blackbirds and lapwings that could not be considered competitors, (Lever, 2009)

References

Publications

Cosgrove, P.J., Maguire, C.M. and Kelly, J. (2008). Ruddy Duck (Oxyura jamaicensis) Management Plan. Prepared for NIEA and NPWS as part of Invasive Species Ireland. http://invasivespeciesireland.com/wp-content/uploads/2010/11/Ruddy_Duck_ISAP.pdf Site accessed 7 October 2017.

Hughes, B. (2005). Oxyura jamaicensis. IUCN/SSC Invasive Species Specialist Group (ISSG) [Online].

Henderson, I (2009) Progress of the UK Ruddy Duck eradication programme. British Birds 102: 680–690. https://www.britishbirds.co.uk/wp-content/uploads/article_files/V102/V102_N12/V102_N12_22_32.pdf Site accessed 7 October 2017.

Henderson, I and Robertson, P (2007) Control and eradication of the North American ruddy duck in Europe. Managing Vertebrate Invasive Species, 16 http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1015&context=nwrcinvasive Site accessed 7 October 2017.

Henderson, I. S. (2006). Recent measures to control Ruddy Ducks Oxyura jamaicensis in the United Kingdom. Waterbirds around the world, 822-825. http://jncc.defra.gov.uk/PDF/pub07_waterbirds_part6.1.9.pdf Site accessed 7 October 2017.

 Lever, C. (2009) The Naturalized Animals of Britain and Ireland. New Holland Publishers, London, UK.

Munoz-Fuentes, V.., Green, A. J., Sorenson, M. D., Negro, J. J., & Vila, C. (2006). The ruddy duck Oxyura jamaicensis in Europe: natural colonization or human introduction?. Molecular Ecology, 15(6):1441-1453.

Robertson, P.A., Adriaens, T., Caizergues, A., Cranswick, P.A., Devos, K., Gutiérrez-Expósito, C., Henderson, I., Hughes, B., Mill, A.C. and Smith, G.C., (2015). Towards the European eradication of the North American ruddy duck. Biological Invasions, 17(1), pp.9-12.

Global Invasive Species Database

IUCN Red List of Threatened Species

DAISIE Factsheet

CABI Datasheet

Images