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Mallard: the story on HearLore | HearLore
Mallard
In 2018, a single male mallard named Trevor appeared on the remote Pacific island of Niue, an atypical location for the species, and became known as the world's loneliest duck before dying there the following year. This solitary drake, named after a New Zealand politician, highlights the incredible adaptability of the mallard, a species that has spread from its native temperate and subtropical regions of the Americas, Eurasia, and North Africa to nearly every corner of the globe. Originally described by Carl Linnaeus in the 10th edition of Systema Naturae published in 1758, the mallard was given the binomial name Anas platyrhynchos, derived from Latin for duck and Ancient Greek for broad-billed. While the species is currently rated as one of least concern by the International Union for Conservation of Nature due to its massive population and wide range, its success has come at a steep cost to biodiversity. The mallard is now considered an invasive species in regions like New Zealand, Australia, and South Africa, where it threatens indigenous waterfowl through genetic pollution. Unlike many other waterfowl that have declined due to human alteration of the environment, the mallard has thrived, often outcompeting native species and hybridizing with them to the point of extinction for the original gene pools.
A Genetic Paradox
The mallard genome, sequenced in 2013, reveals a startling lack of genetic structure between North American and Eurasian populations, despite the vast distances separating them. This genetic fluidity allows the mallard to interbreed with more than 40 species in the wild and an additional 20 in captivity, creating fertile hybrids that challenge the very definition of a species. In the Aleutian Islands, a population of mallards appears to be evolving into a distinct subspecies due to limited gene flow with other populations, yet elsewhere, the species acts as a genetic sponge, absorbing DNA from domestic ducks and other wild relatives. This phenomenon has led to the extinction of unique lineages, such as the Mariana mallard, which was a resident allopatric population derived from mallard-Pacific black duck hybrids and disappeared in the late 20th century. The genetic pollution is so pervasive that the wild mallard's own gene pool is now contaminated by domestic and feral populations, reversing the speciation process and creating a continuum of hybrids that are less adapted to native habitats. Conservationists worry that the complete hybridization of various wild duck gene pools could result in the extinction of many indigenous waterfowl, including the Hawaiian duck and the New Zealand grey duck, which are being swamped by mallard DNA.
When did the mallard named Trevor die on the island of Niue?
The mallard named Trevor died on the island of Niue in 2019 after appearing there in 2018. This solitary drake became known as the world's loneliest duck before his death the following year.
Who first described the mallard species and when was it published?
Carl Linnaeus first described the mallard species in the 10th edition of Systema Naturae published in 1758. He gave the species the binomial name Anas platyrhynchos derived from Latin for duck and Ancient Greek for broad-billed.
Which duck species are currently threatened by mallard hybridization in Hawaii?
The Hawaiian duck and the New Zealand grey duck are currently threatened by mallard hybridization in Hawaii. The Laysan duck was found throughout the Hawaiian archipelago before 400 AD and suffered a rapid decline during Polynesian colonization due to hybridization with mallards.
How many mallard collisions with aircraft have been recorded by the Federal Aviation Administration since 1990?
The Federal Aviation Administration has recorded 1320 mallard collisions with aircraft since 1990. The mallard ranks as the 7th most hazardous bird to both military and commercial aircraft in the United States.
When was the mallard genome sequenced and what does it reveal about genetic structure?
The mallard genome was sequenced in 2013 and reveals a startling lack of genetic structure between North American and Eurasian populations. This genetic fluidity allows the mallard to interbreed with more than 40 species in the wild and an additional 20 in captivity.
What year did the incident of homosexual necrophilia involving a mallard earn an Ig Nobel Prize?
The incident of homosexual necrophilia involving a mallard earned an Ig Nobel Prize in 2003. This event occurred when a male mallard copulated with another male he was chasing after the chased male died upon flying into a glass window.
A breeding male mallard is unmistakable with its glossy bottle-green head, white collar, and purple-tinged brown breast, while the female displays mottled brown plumage that serves as effective camouflage in hidden nesting sites. Both sexes possess a distinct iridescent purple-blue speculum feather edged with white, which is prominent in flight but temporarily shed during the annual summer moult. The species exhibits rare biological anomalies, including spontaneous sex reversal where damaged ovaries in hens cause them to exhibit male plumage, and phenotypic feminization or masculinization. Mallards are precocial, meaning ducklings are fully capable of swimming as soon as they hatch, yet they rely on filial imprinting to instinctively stay near their mother for warmth, protection, and to learn foraging habits. The average life expectancy is three years, though individuals can live up to twenty years, and the species demonstrates a unique predation-avoidance behavior of sleeping with one eye open, allowing one brain hemisphere to remain aware while the other rests. This adaptation, first demonstrated in mallards, is believed to be widespread among birds in general, ensuring survival against a diverse array of predators ranging from red foxes and peregrine falcons to domestic cats and dogs.
The Dark Side of Mating
While mallards are often seen as placid and beautiful, their breeding season reveals a violent undercurrent of aggression and coercion. Males, known as drakes, frequently engage in forced copulation with isolated females, a behavior termed Attempted Rape Flight by ethologist Lebret in 1961, where they chase and peck at females until they weaken and take turns copulating. This aggression extends to other species, with mallards occasionally targeting females of different species, and even to other males, as evidenced by a documented case of homosexual necrophilia where a male mallard copulated with another male he was chasing after the chased male died upon flying into a glass window, an incident that earned an Ig Nobel Prize in 2003. Females are not passive victims; they carry out inciting displays to encourage other ducks to fight, potentially evaluating the strength of potential partners, and will violently attack and sometimes kill stray ducklings that are not their own. The species is also opportunistically targeted by brood parasites, including redheads, ruddy ducks, and other mallards, which lay eggs in their nests, forcing the host to either accept the intruder or abandon the nest entirely.
The Urban Duck
Mallards have become ubiquitous in human-modified landscapes, thriving in urban parks, lakes, and ponds where more sensitive species have vanished. Their ability to coexist with humans is so profound that they are often tolerated or encouraged in human habitats, yet this success has created a new set of problems. In the United States, the mallard ranks as the 7th most hazardous bird to both military and commercial aircraft, with the Federal Aviation Administration recording 1320 collisions since 1990, including one strike at a cruising altitude of 21,000 feet. The species has developed a regional accent in its vocalizations, with urban mallards in London being much louder and more vociferous than their rural counterparts in Cornwall, an adaptation to persistent levels of anthropogenic noise. Despite their adaptability, mallards face unique threats in summer when hot temperatures and reduced water levels create ideal conditions for Clostridium botulinum to propagate, leading to mass die-offs from botulism. Their presence in urban areas has also led to the decline of local species, as mallards compete for resources and nest sites, often driving away or killing native waterfowl.
The Domestic Connection
Almost all domestic duck breeds derive from the mallard, with the exception of a few Muscovy breeds, and were first domesticated in Southeast Asia at least 4,000 years ago during the Neolithic Age. The relationship between the mallard and humans is ancient, with the wild species being eaten in Neolithic Greece and farmed by the Romans in Europe and the Malays in Asia. Unlike their wild counterparts, which are generally monogamous, domestic ducks are mostly polygamous and lack territorial behavior, making them less aggressive. The genetic boundary between wild and domestic mallards is porous, as they are the same species and produce fully fertile hybrid offspring, leading to the contamination of the wild gene pool. This interbreeding has created a situation where pure-bred mallards are rare, and the species is often kept for meat and eggs, with the latter having a strong flavor. The mallard's ubiquity in human environments has made it a common target for hunting, with the species being one of the most common shot in waterfowl hunting due to its large population size, yet it is also protected under national acts and policies in countries like the United Kingdom.
Cultural Icons and Extinction
The mallard has captured the human imagination in literature and film, from the children's picture book Make Way for Ducklings by Robert McCloskey, which centers on a pair of mallards raising their ducklings in the Boston Public Garden, to the animated adventure comedy Migration, which follows a family of mallards trying to migrate from New England to Jamaica. The species has also become a symbol of loneliness and isolation, as seen in the story of Trevor, the mallard that appeared on Niue and became the world's loneliest duck. Despite their cultural prominence, mallards are responsible for the extinction of several unique lineages, including the Mariana mallard and the Laysan duck, which has been reduced to a single island due to hybridization with mallards. The Laysan duck, which was found throughout the Hawaiian archipelago before 400 AD, suffered a rapid decline during Polynesian colonization and is now one of the successfully translocated birds after becoming nearly extinct in the early 20th century. The mallard's ability to hybridize with other species has created a conservation crisis, with the species being considered an invasive threat to biodiversity in regions like South Africa, where it breeds with endemic ducks and produces fertile hybrids that threaten the genetic integrity of local waterfowl.