Mandarin Duck: Where It Comes From and Where It Turns Up

The mandarin duck, Aix galericulata, is an East Asian perching duck and a close relative of the wood duck; the drake, which the BTO calls “gaudy and one of our most resplendent ducks”, carries orange “sails” on its back. It is native to China, Japan, Korea and parts of Russia, but is often seen far from there: on park lakes in southern England, where escaped birds have bred wild since early in the 20th century, in parts of the United States, and, in 2018, in New York’s Central Park.

How to recognise a mandarin duck

For the breeding drake, the RSPB lists “distinctive orange feathers on the side of the face, a purple chest, large orange feathers that stick up like sails on its back, and pale orange flanks”, and a USFWS risk screening adds an “orange-red bill”. The female is “a smart grey and brown”, in the BTO’s words, with “a grey head and white stripe behind the eye, brown back and mottled lower sides” according to the RSPB.

After breeding the drake loses most of this: in the native range, Audubon says, males “start to shed their breeding plumage sometime between May and July”, and the sails are then “Gone.” The Wildlife Trusts give a length of 45 cm and a weight of 520–630 g, the USFWS screening 41–51 cm and 444–500 g, and the BTO 500–700 g for the adults in its sample. None of the sources we read describes the call.

Mandarin duck or wood duck?

Only the hens are a real problem. Ducks Unlimited calls the mandarin “the Asian ecological equivalent of the wood duck”, and the GB Non-native Species Secretariat’s identification sheet separates the females on marks including these: the mandarin hen has “Less white around the eye than wood duck”, “Spotting on the flank” and a “Pink bill”. The mandarin’s American cousin, and the nest boxes that helped it recover, are covered in wood duck.

Where and when you will see one

In the Far East, Animal Diversity Web says, mandarins migrate; the USFWS screening says the species “breeds mainly in eastern Russia, Japan, Korea and northern China, and overwinter mainly in Burma, northeastern India and the Yangtze river in China”. In Britain the RSPB says mandarins “were introduced to the UK from China and have become established following escapes from captivity”. The BTO gives the first record as Berkshire, 1866, and says the species is “now found across England and parts of Scotland and Wales”. The Wildlife Trusts place it on “park lakes and other wetlands with overhanging trees, mainly in South East England”, all year round, often “hiding beneath overhanging willows”. Much smaller populations live in the Netherlands and Switzerland, according to the USFWS screening.

In the United States, California’s Bird Records Committee describes “A moderately sized population, numbering a few hundred individuals” that “has been resident near Santa Rosa, Sonoma County since at least the 1970s”, and probably fewer than 100 in southern California, “likely dependent on artificial nest boxes.” The USFWS screening adds about six breeding pairs in North Carolina. The committee says the species “currently has low potential to be added to the state list”.

What it eats, and how

The USFWS screening says “The Mandarin Duck is a dabbling duck and feeds in particular at night, but also during day”, mainly on aquatic plants and tree seeds such as acorns, sweet chestnuts, beech-mast and hazelnuts, and on corn from stubble fields. Animal Diversity Web gives the basic diet as “water plants, rice and other grains”, and a study of free-ranging pinioned mandarins in the journal Wildfowl found their days taken up with “repetitious feeding, preening, and loafing”. The difference between dabbling and diving is explained in dabbling vs diving ducks, and duck diets in general in what do ducks eat.

Nesting and ducklings

Here the mandarin’s reputation runs ahead of the evidence. Animal Diversity Web says the birds “serve as a symbol of happiness and marital fidelity”, and a Smithsonian label on a Japanese object of the late 17th or early 18th century says mandarin ducks “remain with one mate for life”. The biology is more modest: the USFWS screening states, “The Mandarin Duck is a monogamous species. Pairs are formed in winter.” Animal Diversity Web adds that pairs “may continue for many seasons.” No biology source we read says they stay together for life; the wider question is in do ducks mate for life.

Like the wood duck, the mandarin nests in a tree hole or a nest box, “sometimes high up and a long way from the water”, according to the Wildlife Trusts; WWT and Animal Diversity Web give heights of up to 30 feet. The BTO, the USFWS screening and Animal Diversity Web give a clutch of 9–12 eggs. The female incubates alone, for 28–30 days according to the BTO and Animal Diversity Web, or 28–33 days in the USFWS screening, while WWT says the males “guard the nest”.

Soon after hatching, Animal Diversity Web says, each chick crawls out of the hole and “launches itself into a free fall” towards the mother calling below; the BTO says “Up to 12 ducklings jump from the nest before they can fly and follow the female to the nearest water.” They fly at 40–45 days, according to the BTO.

Why is there a mandarin duck in New York?

Because someone, somewhere, kept one. A drake was first spotted near the pond in Central Park on 10 October 2018, and The New York Times, in an article republished by WRAL, put it plainly: “The male Mandarin duck, native to East Asia, should not be in the middle of Manhattan.” He wore a band on his right leg. The Wildlife Conservation Society said he “did not come from any of New York’s four major zoos”, and David Barrett of the Manhattan Bird Alert account offered three explanations: an escape from a local zoo, an escape from somewhere nearby such as New Jersey, or an owner who “could have tired of having a feathered friend and dumped him in the park.” NPR said “no one can figure out why this one is in New York”.

Captivity is where the sources point. An Audubon article in February 2019 reported that “this bird escaped from captivity”, and Audubon had noted in 2016 that the mandarin is “common in U.S. zoos and private collections”. The California colony began the same way in 1972, “originating from a collection nearby”, according to the USFWS screening.

How mandarin ducks are doing

Secure on paper, and spreading in Britain. The BTO and Animal Diversity Web list it as Least Concern on the IUCN Red List, though we could not check that on the IUCN’s own pages; Animal Diversity Web’s 1999 account said “The current Asian population may be under 20,000 birds.” For the UK the BTO gives 4,400 breeding pairs in 2007–11, a “663% increase 1995 to 2024” and a breeding range that expanded by 1148.7% between 1968–72 and 2008–11.

Whether that growth matters is unsettled. The RSPB gives its UK conservation status as “Not assessed”, the Wildlife Trusts call it an “Introduced, non-native species”, and the BTO lists it under Schedule 9 of the Wildlife and Countryside Act. The USFWS screening notes that in Belgium introduced mandarins “compete indirectly for nest sites with other species”, but rates the overall risk “Uncertain”. In North America, Ducks Unlimited says, mandarins use wood duck nest boxes, “but there doesn’t appear to be significant competition between these species.”

To name a hen, check the white around the eye, the flank and the bill, then try the wild duck identifier; how drakes and hens differ more generally is covered in male vs female ducks.