Mottled ducks communicate with each other by making noise and displaying (see Mating Systems and Behavior).
Their sounds resemble those of mallards. The males have a low raspy "raeb" call. A single call note is an alarm signal and two notes together signify either courtship or conversational calls. The females also have a low, raspy call. It starts out high pitched and lowers in pitch throughout the call. Female calls consist of six notes, the second one is the highest pitched. When the female is alerted, she lets out three or four quick quacks. The female uses a "gagg" note when she is inciting (attracting) her mate.
Communication Channels: visual ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
In Florida, mottled ducks have lost 3.7 million acres of wetland habitat due to drainage for citrus orchards and improved pastures for cattle. In Texas and Louisiana, many of the wetlands have been depleted as a result of industrialization, urbanization, coastal erosion and drainage (approximately 102 to 150 sqaure kilometers are destroyed per year). Feral mallard ducks (which are kept as pets) mate with mottled ducks, which decreases the number of pure mottled ducks in the population. Mottled ducks also tend to breed with other species of ducks, which also decreases their genetic representation in the population. The effects of hunting are undetermined for this species.
Mottled ducks are protected under the US Migratory Bird Treaty Act.
US Migratory Bird Act: protected
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
There are no known adverse affects of mottled ducks on humans.
Mottled ducks often help control mosquito populations and are hunted by humans for food. In addition, their feathers are used to make a good quality down.
Positive Impacts: food ; body parts are source of valuable material; controls pest population
Mottled ducks eat aquatic invertebrates and small fish, and help to regulate their populations. Mammals, birds of prey and other animals eat mottled ducks and help regulate their population. Their consumption of vegetation around their habitats prevents over-growth of these plants.
Mottled ducks are carnivors and herbivores. They eat aquatic invertebrates and small fish. They often eat snails, crayfish, beetles, dragonfly nymphs, fish and midge larvae. Invertebrates make up from 1 to 40 percent of their diet. They also eat seeds, grasses, aquatic vegetation and rice.
Mottled ducks usually feed in pairs in the fall and winter. During the summer, they may feed in small groups of about twenty. From August through October (especially in the rice fields) they often feed in flocks of around three thousand. When the ducks feed alone, they search the marshlands for seeds and invertebrates by sitting on the water and tipping their heads under water (a behavior called dabbling). They rarely dive for food, but when they do, it is for minnows.
Animal Foods: mammals; fish; eggs; insects; mollusks; aquatic or marine worms; aquatic crustaceans
Plant Foods: leaves; seeds, grains, and nuts
Primary Diet: omnivore
Mottled ducks are found only in North America and are year-round residents. They are found in high densities in the intermediate marshlands of Louisiana and Southern Texas. Their population is very dense in the state of Florida from Alachua County to Cape Sable. However, they are found in the highest numbers in the wetlands around Lake Okeechobee and the areas around the Upper St. Johns River. They are also found in small numbers around the Gulf of Mexico, Alabama and the Mississippi coastal borders (approximately one-eighth of the population). A very small population was found as far south as Vera Cruz, Mexico.
Biogeographic Regions: nearctic (Native )
In Florida, mottled ducks are found in freshwater wetlands, ditches, wet prairies and flooded marshes. In some seasons, mottled ducks are also found in rice and flooded fallow fields. In some cases, they have been found in small numbers in mosquito control areas. They stay in the same area year-round.
In Texas and Louisiana, mottled ducks are found fresh and saltwater marshes and brackish ponds. These areas are full of vegetation such as bulrush, long grasses, rice, cutgrass and bultongue.
Habitat Regions: temperate ; terrestrial
Aquatic Biomes: lakes and ponds; rivers and streams; temporary pools; coastal ; brackish water
Wetlands: marsh
Other Habitat Features: estuarine
Mottled ducks have relatively short lifespans, on average they live for only 2 years. They have an annual mortality rate of about 50%. The longest known lifespan in the wild is thirteen years. The expected lifespan in the wild is five years. The expected lifespan in captivity is twenty years.
Range lifespan
Status: wild: 13 (high) years.
Typical lifespan
Status: wild: 60.83 (high) months.
Average lifespan
Status: wild: 24.33 months.
Average lifespan
Status: captivity: 20 years.
Mottled ducks are brown and are not easily distinguished from American black ducks (Anas rubripes). They have an iridescent blue speculum and buffy plumage, which makes them appear lighter than other species. They lack a few features that other ducks have such as white anterior edges on the speculum. These ducks appear to be uniformly dark from a distance. Mottled ducks are sexually dimorphic. The bills of males are bright yellow, but are drab colored in females. The females are grayer whereas the males are very brown in color. The tails of the males have a faint pattern but the tails of the females are patternless. Both sexes have blackish-brown upper sides and undersides. Both also have a smoke-gray U-shaped stripe on their undersides. They weigh from 810 to 1330 g and are 50 to 61 cm long with wingspans from 243 to 270 cm. Males tend to be larger than females.
Range mass: 810 to 1330 g.
Average mass: 1043 g.
Range length: 50 to 61 cm.
Average length: 55 cm.
Range wingspan: 243 to 270 mm.
Average wingspan: 259 mm.
Sexual Dimorphism: male larger; sexes colored or patterned differently; male more colorful
Other Physical Features: endothermic ; bilateral symmetry
To escape from predators, most adults fly away. If they are ducklings and molting adults and are unable to fly, they dive underwater or hide in brush. The adult females are very protective of their broods and quack loudly at any approaching intruders.
Mammalian predators feed on eggs, nesting females, ducklings and adults during molting season. Some of these predators include gray fox (Urocyon cinereoargenteus), red fox (Vulpes vulpes), American mink (Neovison vison), river otters (Lontra canadensis), striped skunks (Mephitis mephitis), ground squirrels (genus Spermophilus) and raccoons (Procyon lotor). Northern harriers (Circus cyaneus) and peregrine falcons (Falco peregrinus) also prey on mottled ducks. In Florida, alligators (Alligator mississippiensis) eat the ducklings and some flightless adults. Snapping turtles (Chelydra serpentina), bullfrogs (Lithobates catesbeianus) and bass (Micropterus salmoides) also prey on ducklings.
Known Predators:
Pair formation begins as early as March. Pairs usually break-up shortly after the eggs are laid and incubation begins. The ducks are monogamous during the breeding season. They are not monogamous for life, however. Each season new pairs are formed. They engage in many courtship displays which include: head-shakes (the male simply shakes his head in the females direction), intro-shakes (the male, to gain the female's attention, treads water then rises above the water and shakes his head), grunt-whistles (the male places his bill in the water, pulls it up while making noise and splashes the water in the air), inciting (the female performs this display for the male after the pair has formed), preen-behind-wing (fake preening).
This whole display takes only about three minutes. The ducks also have another courtship ritual in which the male swims around the female, pulling his head in and out of the water; this behavior is known as bridling.
Mating System: monogamous
Mottled ducks breed once yearly. Eighty percent have formed pairs by November and mating begins in January. The nests are made of matted grass and are on the ground or suspended over shallow water and are in dense grasses. Females lay 5 to 13 eggs per clutch. The eggs take 24 to 28 days to hatch. The ducks fledge after 45 to 56 days. They are independent adults in 65 to 70 days. Both males and females are sexually mature in one year.
Breeding interval: Mottled Ducks breed once yearly.
Breeding season: Mottled ducks form pairs in November; mating starts in January.
Range eggs per season: 5 to 13.
Range time to hatching: 24 to 28 days.
Range fledging age: 45 to 56 days.
Range time to independence: 65 to 70 days.
Average time to independence: 68 days.
Average age at sexual or reproductive maturity (female): 1 years.
Average age at sexual or reproductive maturity (male): 1 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; oviparous
After the eggs hatch, the females lead the brood from the nest. The ducklings are precocial and are able to find their own food. They tend to eat invertebrate larvae when available. The mothers care for the young approximately 20% of the day. The mother spends 34% of her time feeding, 28% resting, 11% preening and 20% watching for predators. The females give alarm calls if an intruder approaches the nest or her young. Broods tend to gather together at night to keep safe. The females usually stay with the ducklings until they can fly (about 45 to 56 days).
Parental Investment: precocial ; pre-hatching/birth (Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Female, Protecting: Female)
The mottled duck (Anas fulvigula)[note 1] or mottled mallard is a medium-sized species of dabbling duck. It is intermediate in appearance between the female mallard and the American black duck. It is closely related to those species, and is sometimes erroneously considered a subspecies of the former.
Along the Gulf of Mexico coast, the mottled duck is one of the most frequently banded waterfowl. This is due in part to the fact that it is mostly non-migratory.[3] Approximately one out of every 20 mottled ducks is banded, making it an extremely prized and sought after bird among hunters.
There are two distinct subspecies of the mottled duck. One subspecies, the Gulf Coast mottled duck (A. f. maculosa), lives on the Gulf of Mexico coast between Alabama and Tamaulipas (Mexico); outside the breeding season, individual birds may venture as far south as Veracruz. The other, the Florida mottled duck (A. f. fulvigula), is resident in central and southern Florida and occasionally strays north to Georgia. The same disjunct distribution pattern was also historically found in the local sandhill cranes. Individuals of both subspecies were introduced into South Carolina in the 1970s and 1980s, where the birds of mixed ancestry have greatly expanded in range, extending through the Atlantic coastal plain of Georgia into northeastern Florida.[4][5]
The adult mottled duck is 44 to 61 cm (17–24 in) long from head to tail. It has a dark body, lighter head and neck, orange legs and dark eyes. Both sexes have a shiny green-blue speculum (wing patch), which is not bordered with white as with the mallard. Males and females are similar, but the male's bill is bright yellow, whereas the female's is deep to pale orange, occasionally lined with black splotches around the edges and near the base.
The plumage is darker than in female mallards, especially at the tail, and the bill is yellower. In flight, the lack of a white border to the speculum is a key difference. The American black duck is darker than most mottled ducks, and its wing-patch is more purple than blue. The behaviour and voice are the same as the mallard.
Mottled ducks feed by dabbling in shallow water, and grazing on land. They mainly eat plants, but also some mollusks and aquatic insects. The ducks are fairly common within their restricted range; they are resident all-year round and do not migrate. Their breeding habitat is brackish and intermediate coastal marshes, but they will also use human developed habitat such as retaining ponds, water impoundments, and agricultural land during the breeding season.[3] According to a review of their breeding behaviors, mottled duck nests may be found in "pastures, levees, dry cordgrass marsh, cutgrass marsh, spoil banks, and small islands."[3]
Measurements:[6]
The Floridian population, which occurs approximately south of Tampa, is separated as the nominate subspecies Anas fulvigula fulvigula and is occasionally called the Florida mottled duck or Florida mallard. It differs from the other subspecies, the Gulf Coast mottled duck (A. f. maculosa) (etymology: maculosa, Latin for "the mottled one"), by being somewhat lighter in color and less heavily marked; while both subspecies are intermediate between female mallards and American black ducks, the Florida mottled duck is closer to the former and the Gulf Coast mottled duck closer to the latter in appearance; this is mainly recognizable in the lighter head being quite clearly separated from the darker breast in Gulf Coast mottled ducks, but much less so in Florida mottled ducks. As the subspecies' ranges do not overlap, these birds can only be confused with female mallards and American black ducks however; particularly female American black ducks are often only reliably separable by their dark purple speculum from mottled ducks in the field.
mtDNA control region sequence data indicates that these birds are derived from ancestral American black ducks, being far more distantly related to the mallard, and that the two subspecies, as a consequence of their rather limited range and sedentary habits, are genetically well distinct already.[7]
As in all members of the "mallardine" clade of ducks, they are able to produce fertile hybrids with their close relatives, the American black duck and the mallard. This has always been so to a limited extent; individuals of the migratory American black ducks which winter in the mottled duck's range may occasionally stay there and mate with the resident species, and for the mallard, which colonized North America later, the same holds true.[7] Genetic tools have been developed in order to robustly classify hybrids and to assess and monitor the genetic dynamics of introgression between the Florida mottled duck and the mallard.[8]
While the resultant gene flow is no cause for immediate concern,[note 2] habitat destruction and excessive hunting could eventually reduce this species to the point where the hybridization with mallards would threaten to make it disappear as a distinct taxon.[9] This especially applies to the Florida mottled duck,[10] in the fairly small range of which rampant habitat destruction due to urbanization and draining of wetlands has taken place in the last decades; this, in combination with climate change affecting the Everglades, could be sufficient to cause the Florida mottled duck to decline to a point where hunting would have to be restricted or prohibited.[7] At present, these birds too appear to be holding their own, with a population of 50,000-70,000 individuals. While hybridization is common, double white bars above and below the speculum are not a sufficient indicator of hybridization and therefore should not be used to determine genetics.[1]
Male and female - Florida
Female - Florida
Male - Florida
Male - Florida
{{cite web}}: Missing or empty |title= (help) The mottled duck (Anas fulvigula) or mottled mallard is a medium-sized species of dabbling duck. It is intermediate in appearance between the female mallard and the American black duck. It is closely related to those species, and is sometimes erroneously considered a subspecies of the former.
Along the Gulf of Mexico coast, the mottled duck is one of the most frequently banded waterfowl. This is due in part to the fact that it is mostly non-migratory. Approximately one out of every 20 mottled ducks is banded, making it an extremely prized and sought after bird among hunters.
