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The
West Indian Whistling Duck is the largest of the eight species
of Whistling Duck to be found in the world. It has numerous other common
names, including Cuban Tree Duck, Black-billed Whistling Duck, Mangrove
Duck, Night Duck, Yaguaza and Gingeon. Its Latin name, Dendrocygna
arborea, means tree-swan, and acknowledges the fact that
many of these birds spend large parts of their time perched in trees.
With its long neck and legs,
this duck is actually far more closely related to geese and swans, and
like those birds, moults just once a year.
Generally, the West Indian
Whistling Duck, whose call is a haunting four or five syllable whistle,
is between 20 and 24 inches tall, and weighs
about two and a half pounds. It has a chestnut brown forehead, with
a dark brown/black stripe from the crown down the back of the neck.
Its
face is pale ginger, fading to grey and white on the chin, throat and
neck. The feathers on the back and tail are medium brown, as are the
wings. The primary feathers of the upper wing have silvery buff patches
on them. The duck's sides and flanks are black with distinctive
white mottling. They have black beaks and the legs and feet are dark
blue/black. In flight, the duck's legs trail behind them and are
longer than the tail.
Normally a night feeder, the West Indian Whistling
Duck spends daylight hours roosting in mangroves, woodlands or swamps.
At dusk they fly
to their feeding grounds which are usually ponds (fresh, brackish or
salt
water) surrounded by thick vegetation or seasonally flooded grasslands.
The ducks are largely vegetarian, feeding on fruits and seeds of grasses
and other plants. They also eat freshwater snails, however, and some
even develop a taste for tadpoles!
The breeding season varies from island
to island. In Cayman it seems to occur at any time throughout the year,
but most commonly at the
onset of the rainy season in May/June. Breeding pairs often stay together
for
more than one season, and both male and female build the nest. The
nests can be found in tree holes and on horizontal branches, although
it is
not uncommon for pairs to nest on or near the ground, or on ironshore
outcrops in lagoons. Clutches typically number between 5-13 eggs and
both birds take turns every 24 hours to incubate them. When the fledglings
hatch, both parents assist in care for several weeks afterwards.
The
first recorded sightings of the West Indian Whistling Duck in the Cayman
Islands were made in 1916 by T.M. Savage-English. In his Notes
on Some of the Birds of Grand Cayman, West Indies, Savage-English
mentions them as being "by no means uncommon". By
1971, they had been described in Avifauna of the Cayman Islands by
D.W. Johnson et al as an "uncommon breeding resident". In
1985, P.E. Bradley estimated a total, but falling population of about
320 ducks, comprised of flocks
ranging from 12 and 60 birds. It is thought that between 1985 and 1991,
the ducks suffered a further drastic decline, down to less than 100
birds in Grand Cayman, with similar losses in Little Cayman. From 1990
to 1992,
the Cayman Islands Bird Club organised a series of watches in Lower
Valley and North Sound Estates in Grand Cayman, but never found more
than 28
birds in a flock. This was a low point in the fortunes of the West
Indian Whistling Duck in Cayman.
The ensuing upward trend of recent
years can be largely attributed to the work of just one man. In December,
1990, a single pair of ducks
and
seven young birds began to feed at the farm of Mr. Willie Ebanks,
at Hutland, Northside, in Grand Cayman. Willlie grows fruit and vegetables
and raises pigs, and he noticed that the ducks were nibbling at the
pig food. So he began to put out extra feed for the birds. Soon the
ducks
were joined by others and by 1992, 16 pairs were regularly feeding
at his farm. In 1995, the numbers were estimated to be close to 300
birds.
The ducks arrive at dawn and return at dusk to dine on the split
corn
put out for them. In 1992, in recognition of his work, the National
Trust for the Cayman Islands presented Willie with its prestigious
Award of
Distinction for Environmental Conservation. A reduction in illegal
hunting on Little Cayman has also allowed the ducks to recover there,
and in
1995, they bred on Cayman Brac for the first time in many years.
Also
in 1995, the Trust hosted a study conducted by Fiona O'Brien, from
Queen's University, Belfast, Northern Ireland, to assess the
duck population at Willie's farm. The study aimed at establishing
if and how the supplemental feeding programme had affected the
bird's behaviour; whether the ducks continued to use their remaining
natural
feeding and breeding grounds; and if the ducks were becoming overly
domesticated. It is encouraging to report that the study found
that many of the potential
dangers have not yet materialised. The ducks are spending less
than 30% of their time at the farm, so clearly still making use of
their
natural
feeding grounds, and are teaching their young to do the same. Many
appear to be breeding in the Central Mangrove Wetland, far from
the farm. Today,
the West Indian Whistling Duck is classed as a vulnerable species:
its range is confined to the Cayman Islands, the Greater Antilles,
and the
Bahamas. The duck's natural predators are few, but introduced species
such as rats, feral dogs and cats, and, on some islands, the Indian
Mongoose, present a very real hazard to its survival. The serious
regional decline
in its numbers in recent years is due principally to the rapid
development of wetlands, the misuse of pesticides, and hunting. Hunting
of the
West Indian Whistling Duck is now illegal in the Cayman Islands,
but poaching
remains the biggest single threat to this bird. In 1995, the Cayman
Islands Government expressed determination to protect this species
with stricter
control of hunting and gun licenses. With such measure in place,
it is hoped that the numbers of ducks in Cayman will continue to
rise
to ensure
its future in the wild.
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