The long-tailed duck, also known as oldsquaw, is a medium-sized sea duck that breeds in the Arctic regions and winters along coastal waters further south. With its distinctive long tail feathers, mostly white plumage, and black cap markings, the long-tailed duck is a prized gamebird and readily identifiable. But is it truly a sea duck? To answer this question, we must examine the characteristics and behaviors of the long-tailed duck and how they compare to other sea duck species.
Defining Sea Ducks
Sea ducks comprise a tribe called Mergini within the waterfowl family Anatidae. There are approximately 20 species of sea ducks, including eiders, scoters, mergansers, and other ducks that spend the majority of their lives in marine habitats. Compared to dabbling ducks and other waterfowl that primarily live in freshwater wetlands and ponds, sea ducks are well adapted to life at sea. Some key characteristics of sea ducks include:
– Shorter legs set further back on their bodies, which provides an advantage when diving and swimming underwater. Their feet are also webbed for powerful propulsion in the water.
– Dense, waterproof plumage to insulate them against the cold ocean waters where they feed. Many species also have a thick layer of down feathers.
– Narrower wings that allow them to maneuver well while flying over the ocean and dive from the air into the water.
– Salt glands that enable them to excrete excess salt from their bodies, allowing them to drink saltwater.
– Mostly fish and marine invertebrate diets obtained by diving to depths of several meters. Some species may also supplement with mollusks, crustaceans, aquatic plants.
– Courtship, breeding, and nesting behaviors adapted to coastal habitats and Arctic regions near oceans. Nests are often built on the ground lined with down near water.
So in summary, sea ducks share a suite of morphological, physiological, and behavioral traits that allow them to live and thrive in marine environments.
Long-tailed Duck Characteristics
Now let’s take a closer look at the long-tailed duck itself and how it compares to these sea duck hallmarks:
Physical features
– Compact, chunky body shape efficient for diving. Body length 16-24 in (40-61 cm).
– Short legs located centrally on body rather than along sides like dabbling ducks. Strong webbed feet propel diving.
– Dense plumage with waterproof, insulating feathers. Thick down layer. Male has black-and-white pattern; female mostly brown.
– Long tail of up to 4 in (10 cm) in male and 2 in (5 cm) in female. Helps with steering and braking underwater. Distinctive trait.
– Wingspan of 26-29 in (66-74 cm). Wings narrow and pointed for agile flight over ocean.
Diet and feeding
– Diet consists mainly of marine invertebrates like mollusks, crustaceans, fish, and fish eggs. May also occasionally eat aquatic plants and grasses.
– Forages by diving and swimming underwater. Can dive to depths over 60 ft (18 m).
– Has salt glands to remove excess sodium from saltwater food sources.
Breeding and nesting
– Breeds in Arctic regions of Alaska, Canada, Greenland near ocean coasts and inland lakes.
– Male courtship displays include head bobbing, vocalizations, and ritualized poses.
– Nests on ground very close to water. Nest is shallow scrape lined with down feathers.
– Lays 5-7 eggs. Incubation around 27 days. Ducklings leave nest shortly after hatching.
Migration and wintering
– Long-tailed ducks are migratory. Breed in the Arctic summer then migrate in winter to saltwater and freshwater coastal habitats along southern Canada, northern U.S., Scandinavia, Russia, northern Europe and Asia.
– Winters along sea coasts, bays, estuaries. Also uses inland lakes, rivers.
– While wintering feeds on mollusks, crustaceans. Continues diving for food in shallow waters.
So in all aspects of its anatomy, diet, breeding biology and migratory patterns, the long-tailed duck exhibits typical sea duck characteristics. It is well adapted to thrive in both northern marine environments and more southern coastal wintering grounds.
Comparison to Other Sea Ducks
To further illustrate that the long-tailed duck fits squarely into the sea duck group, let’s compare some of its features to a close relative, the common eider:
Common eider
– Stocky seaduck with dense, waterproof plumage. Male has black-and-white markings.
– Feeds on mollusks, crustaceans caught by diving underwater.
– Nest is on ground lined with down feathers. Female incubates eggs.
– Breeds in Arctic and subarctic coastal regions in summer.
– Winters along northern coastal waters.
Long-tailed duck
– Also stocky, with waterproof insulating feathers. Male black-and-white patterned.
– Dives for marine invertebrates, fish, fish eggs.
– Nest on ground with down feather lining. Female incubates.
– Breeds in Arctic near coasts and inland lakes.
– Winters along northern coastal habitats.
As you can see, the long-tailed duck and common eider share very similar breeding ecologies, plumage traits, foraging behaviors, preferred foods, and habitat preferences throughout their annual cycle. These overlapping traits are characteristic of the sea duck group that both species belong to.
Conclusion
In summary, the long-tailed duck exhibits all the typical physical, behavioral, and ecological adaptations of a sea duck species. Key sea duck traits like its compact diving body shape, salt gland, foraging ecology, marine diet, breeding habitat, and migration patterns clearly identify the long-tailed duck as a specialized member of the seaduck tribe Mergini. It belongs to the same tribe as other canonical sea ducks like eiders, scoters, and mergansers that inhabit northern marine environments. So based on this evidence, the long-tailed duck can definitively be classified as a true sea duck species. Understanding exactly which taxonomic group specialized birds like the long-tailed duck belong to allows us to better understand their evolution and ecology within coastal and ocean habitats.
