Anas flavirostris

Geographic Range

Speckled teals ( Anas flavirostris ) occupy the eastern shoreline of South America. Their northern-most limits extend to central Colombia and their southern range to Tierra del Fuego, at the southern-most tip of South America.

There are four recognized subspecies of speckled teals, all found in portions of South America. Andean speckled teals ( Anas flavirostris andium ) breed in the eastern Andes Mountains, from central Colombia south to northern Ecuador. Merida speckled teals ( A. flavirostris altipetens ) breed in the eastern Andes Mountains south to Bogota in eastern Colombia. Chilean speckled teals ( A. flavirostris flavirostris ) breed from central Chile and northern Argentina south to Tierra del Fuego. This subspecies also inhabits the Falkland Islands and the Islands of South Georgia. Finally, sharp-winged speckled teals ( A. flavirostris oxyptera ) breed in the Andes from central Peru and western Bolivia south to northern Chile and Argentina. Excluding Chilean teals, A. flavirostris can be said to generally occupy the northwestern coast of South America.

• Biogeographic Regions
• neotropical neotropical
  • native native

Habitat

Differences in habitat use occur among subspecies. All subspecies except Anas flavirostris andium feed on or near lakes and swamps during non-breeding seasons. Anas flavirostris altipetens occupies high-altitude lakes and ponds in the Andes Mountains. This subspecies usually inhabits mountainous regions from 3200 to 4000 meters. Anas flavirostris oxyptera also occupies these high elevation habitats but tends to breed and feed from valleys to the coastline of Chile. Anas flavirostris andium and Anas flavirostris altipetens occupy the Páramo ecosystem, which is the area above the forest line but below the permanent snow line of the Andes Mountains. Anas flavirostris andium is rarely seen below 3200 meters. Finally, Anas flavirostris flavirostris breeds high in the mountains but spend winters in brackish and marine wetland habitats.

• Habitat Regions
• temperate temperate
• tropical tropical
• terrestrial terrestrial
• saltwater or marine saltwater or marine
• freshwater freshwater

• Terrestrial Biomes
• forest forest
• mountains mountains

• Aquatic Biomes
• lakes and ponds
• rivers and streams
• coastal coastal
• brackish water brackish water

• Wetlands
• marsh marsh
• swamp swamp
• bog bog

Physical Description

Speckled teals vary in size, shape, and color, depending on age, sex and subspecies. Anas flavirostris is a relatively small duck. Females are smaller than males, with an average weight of 390 g; males average 430 g. IT measures 37 to 43 cm in length and features a wingspan of 63 to 69 cm. Its colors are more subdued than other ducks in the genus Anas , such as Anas platyrhynchos (mallards). Speckled teals generally have dark colored spots on the neck and breasts that extend towards anterior regions of their bodies. They have tan to brown feathers with black tips. Bill coloration varies with subspecies but is either yellow or blueish gray. Females are less colorful than males, and juveniles less colored than males or females.

Differences in appearance among subspecies are as follows: Anas flavirostris altipetens displays a grayish-brown, densely peppered head and neck. Hence, the name "speckled". The scapulars, which are the shoulders of the duck, are black with lighter colored edges. Anas flavirostris flavirostris has a lesser gray color pattern than A. flavirostris altipetens . Instead, its breast has brownish-black spots that tend to become smaller in size away from the anterior portion of the bird. Its wings are grayish brown with dark spots on the upper mantle. The inner feathers contain most of the green and purple iridescent colors. Anas flavirostris andium displays the same patterning as A. flavirostris altipetens but is darker in overall coloring. Anas flavirostris oxyptera has a much paler head relative to other subspecies, but similar speckle patterning. Bills of A. flavirostris flavirostris and A. flavirostris oxyptera are mainly yellow, whereas the bills of A. flavirostris andium and A. flavirostris altipetens are bluish gray.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• male larger
• sexes colored or patterned differently
• male more colorful

Reproduction

Anas flavirostris is a monogamous species. Both sexes of A. flavirostris perform mating displays. Females utter a decrescendo call of 5 to 12 syllables to incite males. Males also perform a greeting gesture which is uncommon in females. The greeting gesture consists of a gaping open bill with the neck stretched forward. Both males and females perform mutual head pumping as pre-copulation displays. Males perform all of the mating displays, particularly bridling, which is a post-copulation display in which the male duck flings its head back and whistles. Females sometimes nod-swim as males do after copulation. Most females re-mate with their previous partner.

• Mating System
• monogamous monogamous

Anas flavirostris males and females reach sexual maturity at approximately one year of age. Anas flavirostris nests from October to November, usually on the ground near both vegetation and water. They only have one brood of ducklings per year, typically consisting of 5 to 8 eggs. Anas flavirostris flavirostris is unique in the genus Anas , in that it tends to nest in elevated tree cavities or other arboreal sites. Females make a half moon shape nest that they completely cover with their bodies. After laying her clutch, she then incubates her eggs for 24 days. After the eggs have hatched, females take the ducklings to water within 24 hours, where they begin to feed on their own. Most often the male joins the female and assists her in brood care. Near the time of fledging, at about 42 to 49 days, ducklings begin to stray away from their mother.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• oviparous oviparous

The incubation period lasts for 24 days, during which time the hen covers and protects her eggs. After the eggs hatch, the male rejoins the female to take care of the brood until fledging occurs. Fledging is the stage in a young duck's life when the feathers and wing muscles are sufficiently developed for flight. Fledging in A. flavirostris occurs 42 to 49 days after hatching. Until their wings have fully developed, young are still dependent on their parents for protection. The young remain with their parents for an unknown period of time after fledging. The male often leaves the female to care for the young in these late stages.

• Parental Investment
• precocial precocial
• male parental care male parental care
• female parental care female parental care
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • male
    • female
  • protecting
    • male
    • female
• pre-independence
  • provisioning
    • female
  • protecting
    • female

Lifespan/Longevity

There is little research on speckled teals at this time but there have been reports of blue-winged teals ( Anas dicors ) surviving up to 17 years. Cinnamon teals ( Anas cyanoptera ), which are close relatives to speckled teals, have a survival rate of 29% for juveniles in the first year and of that 29% only 46% survive the second year. There have been reports of cinnamon teals surviving 13 years in the wild.

Behavior

The behaviors of speckled teals are similar to that of other teal species. Preening behind the wing occurs in both male and female birds. They can be found in flocks ranging from 10 to 20 birds, and in some cases population sizes may exceed 200 individuals. Pre-flight head shaking and jerking is performed, and they are known to be very fast fliers. In winter months, speckled teals are known to stay in breeding pairs but this behavior is thought to be for safety reasons and not for courtship purposes. Displays of greeting gestures occur anytime that both male and females are present. In captivity, these birds show little fear of humans and tend to do very well. Some populations of speckled teals are migratory, whereas others remain in the same general area. Southern populations often migrate north to spend the winter months, and mountainous populations migrate to lower elevations at this time.

• Key Behaviors
• flies
• natatorial natatorial
• diurnal diurnal
• motile motile
• nomadic nomadic
• migratory migratory
• social social

Home Range

There is little information available on the home range of speckled teals. However, blue-winged teals ( Anas dicors ) have been reported to defend small territories around their nest sites during the breeding season.

Communication and Perception

Communication is common between male and female speckled teals, but it typically takes the form of mating displays or rituals. Agnostic behavior occurs between males and is usually competitive, although these displays have multiple purposes. Generally, A. flavirostris is not territorial. Instead, if both males and females are present, displays may be used to ward off potential competition from other males and to attract potential mates.

Perception in speckled teals is visual and acoustic. Speckled teals use visual cues from the flock to be warned against predators as well as during reproductive behaviors. Acoustic perception in speckled teals also is used during courtship. Like most birds, speckled teals perceive their environment though visual, auditory, tactile and chemical stimuli.

• Communication Channels
• visual visual
• acoustic acoustic

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Food habits for speckled teals are similar to those of other teals. All teal species are omnivores. Speckled teals are dabbling ducks, meaning they stay on the surface and dip for food rather than diving down in the water. They typically consume a variety of small, freshwater invertebrates, such as amphipods (Order Amphipoda ) and molluscs (Phylum Mollusca ). During colder seasons, A. flavirostris develops a wider, more opportunistic diet, sometimes feeding on rotting kelp, as well as seeds along the shoreline. Anything small and somewhat nutritional may be included in the diet of A. flavirostris .

• Primary Diet
• omnivore omnivore

• Animal Foods
• insects
• mollusks
• aquatic crustaceans
• other marine invertebrates
• zooplankton zooplankton

• Plant Foods
• seeds, grains, and nuts
• macroalgae macroalgae

Predation

The major predator of Anas flavirostris is humans through hunting activities. Flock size can be as large as 200 individuals and this is thought to be a defense mechanism against predation. As it is a ground nesting species, speckled teals are likely at risk of predation by terrestrial mammalian predators. Young ducklings are essentially helpless and very vulnerable to attack. Specific, wild predators of speckled teals are currently unknown.

Ecosystem Roles

Speckled teals ( A. flavirostris ) typically flock together, but they are occasionally found in group flocks with Anas cyanoptera and Anas versicolor . Speckled teals keep crustaceans populations in check, as well as rotting kelp. They also feed on different kinds of seeds, which plays an important role in seed distribution.

Little is known about parasites that affect Anas flavirostris but there is some evidence of an asymptomatic nematode ( Ascarid ) infection. This is an infection of the caecum, which is a pouch at the beginning of the large intestine. It can cause caecal mucosa and petechial hemorrhages with heavy infection.

• Ecosystem Impact
• disperses seeds
• biodegradation biodegradation

Economic Importance for Humans: Positive

Speckled teals are one of ten species of duck that are hunted in South America. Speckled teals are difficult to hunt because of their fast, unpredictable, and low flight pattern, but they are a popular food item.

• Positive Impacts
• food food

Economic Importance for Humans: Negative

There are no known adverse affects of Anas flavirostris on humans.

Conservation Status

Anas flavirostris shows no vulnerability and is listed as least concern on the IUCN red list. No conservation efforts are being made other than the preservation of the migration routes. The greatest threat to A. flavirostris is habitat fragmentation, but as of now that does not appear to be affecting the population sizes.

Additional Links

Encyclopedia of Life

Contributors

Robert P. Barksdale (author), Radford University, Raymond H. Simpson (author), Radford University, Christine Small (editor), Radford University, Rachelle Sterling (editor), Special Projects.

References

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