Sarkidiornis melanotos
Silhouette: Sheatherius · PhyloPic
In 3 days <5% in a week ~10%
The knob-billed duck (Sarkidiornis melanotos) or African comb duck is a type of duck found along the tropical/sub-tropical wetlands and waterways of Sub-Saharan Africa and the island of Madagascar, as well as most of South Asia and mainland Indochina.
Most taxonomic authorities classify the knob-billed duck and the comb duck separately. A misidentified species of extinct Mauritian comb duck was initially described from unrecognised remains of the Mauritius sheldgoose (Alopochen mauritiana); this was realised as early as 1897, but the printed case of mistaken identity can still, occasionally, be found in modern-day sources.
Uncertainty surrounds the correct systematic placement of this species. Initially, it was placed in the dabbling duck subfamily Anatinae. Later, it was assigned to the "perching ducks", a paraphyletic assemblage of waterfowl most of which are intermediate between dabbling ducks and shelducks. As the "perching ducks" were split up, the knob-billed duck was moved to the Tadorninae or shelduck subfamily.
Analysis of mtDNA sequences of the cytochrome b and NADH dehydrogenase subunit 2 genes, however, suggests that it is a quite basal member... Wikipedia →
Rare
Under 5% of wildlife watchers report a Comb Duck sighting in New Delhi on a given day, based on 61 verified sightings from GBIF citizen-science data. It is the 154th most-seen of the 248 birds we can rate there. Over three days the chance rises to under 5%, and over a week to about 10%, if each day is a fresh chance.
Any time of year
In every month with enough records, under 5% of wildlife watchers report a Comb Duck in New Delhi on a given day, so our monthly data shows no clear season.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Comb Duck sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
20th of 27
Of the 27 cities where we can rate Comb Duck sightings, New Delhi ranks 20th at under 5%. The best odds are in Rajkot (India, about 30%), Antananarivo (Madagascar, about 30%) and Surat (India, about 20%).
Same family: Anatidae
The closest relatives of the Comb Duck that you can see in New Delhi (family Anatidae, Ducks, Geese, and Swans) are Indian Spot-billed Duck (about 20%), Northern Shoveler (about 10%) and Gadwall (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Comb Duck is recorded against all the birds logged in New Delhi (61 verified sightings), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
