By Risidra Mendis
The Comb Duck, spotted at the Yala National Park after a lapse of over 80 years, was once again being observed in larger numbers at the Wewegama Tank in the Mattala Managed Elephant Range (MER) in June 2012.
The Comb Duck species (Sarkidiornis melanotus), believed to be a native of Sri Lanka, was presumed to be wiped out as there were no recordings of its presence in the country for many years.
However, it was nature lover Indika Nettigama who first came across a female bird of this kind in Block 1 at Rukvilla in the Yala National Park on 21 June 2012, while on safari tour.
A male bird was also spotted in the same area, on the same day by Lalith Ramanayake and Bird Club President Nanda Senanayake.
Environmentalists welcomed the good news of the sighting of five male Comb Ducks on 30 June 2012, which were sitting on a small mound in the middle of the Wewegama Tank in the Mattala MER, by Environmental Foundation Limited (EFL) Director, Vimukthi Weeratunga.
The birds were again observed from 1 to 3 July. They were seen resting at the edge of the tank in the evening of 1 July and early morning of 2 July.
Weeratunga said the birds may have spent the night near the tank, roosting on the ground. “During the day, they were observed feeding and resting on the water, close to the edges and on a couple of mounds in the middle. They fed in the shallow areas by swimming fairly low into the water and submerging the head and neck for short periods, and displayed dabbling behaviour in deeper parts,” he explained.
When swimming from one place to another, the Comb Ducks rode higher in the water. Observations made by Weeratunga revealed the group kept together when feeding and resting and took turns to keep watch. “When disturbed by movement of people or cattle at the edges of the tank, they took wing, did a circuit and landed back on the water in an area away from the disturbance,” Weeratunga said.
The EFL Director went on to say the birds were not noticeably shy and less spooked than the black-winged stilts and whistling teal, adding that on 3 July, however, they were not observed at the tank at 6 a.m., but flew in at about 9 a.m., most likely having spent the night somewhere else.
The birds were last observed at Wewegama in the morning of 5 July. But, a survey of other tanks in the area failed to find any trace of the Comb Duck.
“All five individuals sported ‘combs’ and were males. The speckling on the head and neck and the size and shape of the combs were variable, enabling to distinguish the individuals. One of the individuals had noticeably heavier speckling making and the head and neck appeared almost black,” Weeratunga said.
Nature of Comb Duck
The EFL Director said the Comb Duck has a wide distribution in South and Central America, sub-Saharan Africa, Madagascar, and South and Southeast Asia. “In Sri Lanka, in the 19th century it was found near tanks situated in forested parts of the dry zone, including the Northwest, Wanni, Anuradhapura, Trincomalee, Batticaloa and Hambantota areas,” Weeratunga explained.
The Wewegama Tank in the Hambanthota District is a small rain-fed reservoir, approximately 4.5 ha in extent and is surrounded by forest and situated on the border of the Mattala MER.
“The road from Wewegama to Usgala-Andarawewa and the perimeter electric fence of the MER lie along the dam of the tank. The paddy fields irrigated from the tank lie downstream and are usually cultivated only in the Maha season. Wewgama is a fairly shallow tank with dense submerged aquatic vegetation in the shallows, but little floating vegetation. The water recedes during the dry season, exposing the tank bed, which is covered in short grass and herbs,” Weeratunga explained.
He went on to say that according to his early morning observations, the birds spent the night at the shallow areas of the tank near the edge of the water while staying close to each other for safety, adding that they became active as the sun rose up and spent much of their time feeding in a group close to each other in the shallow areas of open water.
“They came to rest on the small mound in the middle of the tank for intermittent quick preening and resting during their feeding time. Quick resting and preening lasted two to five minutes and before they got back to the water for feeding again. However, a 20-30 minute long resting was also observed,” Weeratunga revealed.
Resident duck species
According to the Director, the Comb Duck has the dubious distinction of being considered the only resident bird species to have been extirpated from Sri Lanka with its last record being an unconfirmed sighting in the 1960s.
The Comb Duck is one of the largest three resident duck species found in Sri Lanka. It shows marked sexual dimorphism in size with males 76 cm and females 66 cm in length and is easily identified by the unique semicircular prominence (‘comb’) extending from the forehead over the beak in males, which is absent in females.
They are usually found in wetland areas and tend to feed on vegetation, grass seeds and small snails, but will occasionally eat small fish or invertebrates. The female incubates around six to eight eggs for about 30 days. The eggs are white or greenish-white in colour. But unlike other species, the female does not line her nest with down.
Comb Ducks are generally peaceful and do well in a mixed aviary, but the males should be watched as they can become somewhat aggressive during the breeding season. This species, as with other tree ducks, practice dump nesting where several females lay their eggs in one nest. Such nests may even hold more than 50 eggs. The nest sites are variable but most frequently made on the ground, in grass or reed beds.
“In view of the pan tropical range and its abundance, the comb duck has been placed in the ‘Least Concern’ category of IUCN. However, given its history in Sri Lanka, an active effort at its conservation in the island is indicated. Given their ability to travel long distances, and that all individuals observed were males, it is probable that the observed comb ducks were visitors from India. While unlikely, a foray from a yet undiscovered relict resident population in Sri Lanka is also possible,” Weeratunga explained.
“The Comb Duck is also a potential target for poachers as it is well known that the British colonists were responsible for the extinction of this bird from the country years ago. The Comb Duck was hunted as a sport and for food by these British colonists,” says Environment lawyer Jagath Gunewardene said.
Other animals and birds observed at the tank by Weeratunga include the Water buffalo that are herded around the tank and lie immersed in the shallows during the day, elephants that visit the tank seasonally and sometimes in herds of up to about 50, the Lesser whistling teal, black winged stilts, pond herons, egrets, grey herons, common kingfishers, pygmy cormorants, and Indian darters are commonly observed.
Increasing awareness of the unique status of this species and enlisting local communities in its protection is important for its conservation in Sri Lanka courtesy: Ceylon Today