NT
West Indian Whistling-duck Dendrocygna arborea



Justification

Justification of Red List Category
This species is precautionarily maintained as Near Threatened because in the past it has undergone substantial declines in its population size. Present knowledge suggests that these declines are historical and the species is now increasing in parts of its range. While the population trend has been positive over the last three generations, this was largely due to successful conservation action. The species remains highly conservation-dependent, and the cessation of conservation action would likely lead to a rapid deterioration in status and a listing under a threatened category. Moreover, it is feared that the species may potentially decline in the future, as the impacts of climate change may degrade its wetland habitats.

Population justification
The global population is estimated to number 10,000-19,999 individuals (derived from L.G. Sorenson in litt. 2007 and L. Mugica in litt. 2007). This equates to 6,667-13,333 mature individuals, rounded here to 6,000-15,000 mature individuals. The largest subpopulation of up to 14,000 individuals is found in Cuba (González Alonso et al. 2012). A further 1,500 individuals occur in the Bahamas; 4,500 individuals are found on other islands. Overall, the estimate of the global population size is conservative; it may be revised upwards if more recent estimates become available.

Trend justification
Once abundant and widespread, West Indian Whistling-duck has declined throughout most of its range in the past. Despite facing a variety of threats, the population is currently increasing at a moderate rate, owing to conservation efforts throughout the range (L. G. Sorenson in litt. 2012). Since 1997, environmental education and awareness campaigns have been carried out, which proved successful in changing attitudes and so far encouraged the creation of protected areas and reduced illegal hunting of the species (Sorenson et al. 2004, Lawrence 2019). The population declines therefore seem to be historical, and the population is currently assumed to be recovering due to intense conservation action. The population is estimated to have increased at a rate of 10-19% over the last three generations (15.9 years). While parts of the population show signs of recovery, the species is dependent on active conservation measures, without which it would potentially qualify as threatened. Moreover, there is concern that future climate change and extreme weather events may negatively impact the species’s habitat availability (L. G. Sorenson in litt. 2019). Therefore precautionarily, the species is suspected to undergo a moderate decline in the future.

Distribution and population

The species occurs in the Caribbean. It historically ranged throughout the Bahamas, Turks and Caicos Islands (to U.K.), Cuba, Cayman Islands (to U.K.), Jamaica, Haiti, Dominica, Dominican Republic, Puerto Rico (to U.S.A.), Virgin Islands (to U.K.), Virgin Islands (to U.S.A.), St Kitts and Nevis (only an occasional visitor in the past and future records unlikely owing to habitat deterioration), Antigua and Barbuda, and Guadeloupe (to France). Currently, breeding populations occur on several islands. At least 1,500 individuals breed in the Bahamas. An unknown number breeds on Turks and Caicos. The breeding population in Cuba is stable and estimated at 14,000 individuals (González Alonso et al. 2012); this number is disputed as possibly being either too pessimistic (L. Mugica in litt. 2011) or too optimistic (L. G. Sorenson in litt. 2012). 800-1,200 individuals breed on the Cayman Islands. The population on Little Cayman decreased sharply following hurricanes in 2007 and 2008. A small population of c.30 individuals is present on Cayman Brac and c.360-650 individuals breed on Grand Cayman mainly near privately-owned ponds or lakes (P. E. Bradley in litt. 2013). The breeding population in Jamaica numbers c.500 individuals, but is apparently declining at a number of key sites (A. Sutton in litt. 2014, 2019). Six populations breed in the Dominican Republic (Ottenwalder 1997). The breeding population in Puerto Rico was found to be larger than assumed with c.300-400 individuals (Goodman et al. 2018, J. C. Eitniear in litt. 2019). 500 individuals breed on Antigua and 50 on Barbuda (Sorenson et al. 2004). On Guadeloupe, the first breeding was recorded in 2008 (L. Sorenson in litt. 2012).

Ecology

This secretive, non-migratory duck is crepuscular or nocturnal and generally considered site faithful, but it will wander in search of water and good habitat during periodic droughts (Staus 1998a, J. Prosper in litt. 2005, Staus 2005, L. G. Sorenson in litt. 2007). During the day, singles, pairs or flocks of up to 100 individuals roost and possibly feed in mangroves, reeds and swampy areas (Sorenson et al. 2004, L. G. Sorenson in litt. 2007). At dusk, birds fly in small flocks to fresh, brackish, and salt ponds, lagoons, ephemeral wetlands, tidal flats and cropfields to feed, returning to roost-sites just before dawn (Staus 1998a). The species tolerates or even favours man-made habitats like dams or agricultural fields (Carboneras and Kirwan 2019). The species often nest on offshore cays, preferably in scrub and coppice (Staus 1998a, J. Prosper in litt. 2005, L. G. Sorenson in litt. 2007). The nest is usually in a cluster of palm fronds, a clump of bromeliads, on a branch, in a tree-cavity, or in a leaf-lined scrape on the ground (Staus 1998a,b, L. G. Sorenson in litt. 2007). Breeding has been recorded in virtually all months, but peaks during summer (Staus 1998b, J. Prosper in litt. 2005, Staus 2005).

Threats

The main threats to the species are loss of suitable wetland habitat, introduced predators and hunting. It has suffered from excessive and under-regulated hunting for subsistence (including eggs) and sport (Staus 1997, 2005, L. G. Sorenson in litt. 2007, 2012). Successful outreach activities by the West Indian Whistling Duck and Wetlands (WIWD) Working Group and the Society for the Conservation and Study of Caribbean Birds (SCSCB) have reduced legal and illegal hunting of the species, however hunting does still occur, including legal hunting in some islands such as Guadeloupe (González Alonso et al. 2012, L. G. Sorenson in litt. 2012). Wetlands are a very limited habitat in the Caribbean, with continuing conversion primarily for development (Staus 1997, J. Prosper in litt. 2005, L. G. Sorenson in litt. 2007, 2012). Habitat used by the species is threatened by a proposed port and logistics hub in Portland Bight Protected Area, Jamaica (L. G. Sorenson in litt. 2014, A. Sutton in litt. 2014). More than 50% of remaining wetlands are seriously degraded by the cutting of mangroves and swamp-forest, pollution (chemical runoff from nearby agriculture, sewage and garbage), water mismanagement, and natural catastrophes such as droughts and hurricanes (Staus 1997, Staus 2005). Predation by introduced species is inadequately documented, but mongoose, raccoons, rats, and feral cats and dogs are known to kill adults and young and eat eggs (Staus 1997, 1998a). Climate models predict a significant summer drying trend in the Caribbean (Neelin et al. 2006), and projected sea-level rise may threaten mangroves (L. G. Sorenson in litt. 2012, 2019), both suggesting that climate change could be a significant future threat to this species. 

Conservation actions

Conservation and Research Actions Underway

CITES Appendix II. CMS Appendix II. It is legally protected throughout much of its range, but law enforcement is inadequate (Staus 1997). Since 1997, the West Indian Whistling-duck Working Group of the Society for the Conservation and Study of Caribbean Birds has conducted a region-wide public education and awareness programme that provides local teachers and educators with training and educational materials and works to raise awareness and appreciation of the value of local wetlands and wetland biodiversity (Sorenson et al. 2004). The project has also sponsored surveys and worked with decision-makers, community leaders and hunters to reduce poaching and encourage protection of local wetlands, especially via development of "Watchable Wildlife Ponds" - wetlands equipped with interpretive signs and viewing areas where local people, school groups, and tourists can easily observe whistling-ducks and other wildlife (Sorenson et al. 2004). Since 2014, an education and awareness programme has been carried out in Antigua and Barbuda with the aim of protecting the species's habitat from degradation and invasive species, and to raise support for the species and its needs among the local population (Lawrence 2019). There are several protected areas in the region but, in general, suitable habitats, especially wetlands, are under-represented and many degraded wetlands should be restored (L. G. Sorenson in litt. 2007). There are plans to establish a re-introduced population on the Virgin Islands (to U.K.) (L. G. Sorenson in litt. 2007). The first record of nesting on Guadeloupe was documented in 2008, probably due to an increasing population in neighbouring Antigua (L. Sorenson in litt. 2012). Some captive breeding populations exist.

Conservation and Research Actions Proposed

Conduct extensive surveys to assess numbers and distribution in each country (Sorenson et al. 2004). Assist local authorities in establishing a long-term monitoring programme (Sorenson et al. 2004). Conserve and restore key sites (Sorenson et al. 2004). Establish legal protection in countries where that is not yet in place and enforce protection in others. Continue public education and awareness programmes (Sorenson et al. 2004) and develop captive breeding efforts (Collar and Butchart 2013).

Identification

48-56 cm. Large, upright, long-necked brown duck with black-and-white markings on flanks. Adult deep brown, darker above with whitish abdomen and black markings on the flanks. Black bill. Immature, less well-marked than adult, black on flanks in streaks. Similar spp. Slightly smaller Fulvous Whistling-duck D. bicolor is more yellowish with a white stripe on side, and white uppertail-coverts. Voice Shrill chiriria whistle. Hints Best seen early morning or late evening.

Acknowledgements

Text account compilers
Ashpole, J, Mahood, S., Hermes, C., Benstead, P., Symes, A., Taylor, J., Temple, H., Wege, D., Isherwood, I.

Contributors
Bradley, P., Bräger, S., Eitniear, J., Levesque, A., Mugica, L., Prosper, J., Sorenson, L. & Sutton, A.


Recommended citation
BirdLife International (2020) Species factsheet: Dendrocygna arborea. Downloaded from http://www.birdlife.org on 28/03/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 28/03/2020.