Waterbirds

Loons

Swans

Mallard and Monochromatic "Mallards"

White Herons

Waterbirds in this case are a general grouping of birds that are not particularly coastal but are generally large and rather obvious and so good subjects for study. They provide a good starting point for a more considered examination, as one or more species are seen nearly throughout the ABA Area. While plumage characters are of course helpful, plumages are generally simple, but structure, range and habitat, and behavior are important keys to examine.

Loons

Red-throated Loon (Gavia stellata)

Pacific Loon (Gavia pacifica)

Arctic Loon (Gavia arctica)

Common Loon (Gavia immer)

Yellow-billed Loon (Gavia adamsii)

First Breeding: ~2– 4 years old

Breeding Strategy: Seasonally monogamous; solitary, territorial

Lifespan: Over 20 years

Graceful aquatic birds, loons are pursuit divers that propel themselves through the water with powerful webbed feet. Awkward and vulnerable on land, they are at home in the water, nimbly seizing fish using their powerful, dagger-shaped bills. They typically make land only to breed, nesting primarily across the high Arctic and boreal forest, building their nests at the edges of lakes or on small islands within lakes. They winter mainly in coastal marine waters, migrating along both coasts during spring and fall. During migration along both coasts (mainly March– April, November–December), loons become more social, sometimes aggregating in large, loose flocks (they do not fly in V formations). If you watch at coastal migration points you may find opportunities to study large numbers of loons in a relatively short time. There, most loons are seen in flight or at a distance, and this is a great way to learn the GISS of each species. Coastal locations hold the largest numbers in migration and winter, but loons can be found on any large body of open water, fresh or salt.

All five of the world's loons occur in North America, and also in parts of temperate and Arctic Eurasia (where they are known as "divers"). Common and Yellow-billed loons are closely related, and they have a similar large build. Arctic and Pacific loons would appear closely related based on their general similarities, but Pacific may actually be more closely related to Common and Yellow-billed. Red-throated Loon appears to be more distantly related to the others, yet all five species share the genus Gavia.

Loons are confused mostly with each other, but occasionally they are mistaken for grebes, mergansers, and especially cormorants. While beautiful and distinctive in breeding plumage, winter loons are more challenging identification subjects, clad in subdued grays, black, and white. At close range most loons are relatively straightforward, and a good study of head pattern, bill shape, and general plumage characters will help confirm identification. But loons always prefer open water, so distance and visibility often complicate identification. In addition, immature loons show variable and confusing plumages. Some one-to two-year-old loons oversummer on the wintering grounds, and these immatures can be especially difficult to identify because of age-related plumage variation and muted plumage patterns from sun bleaching or wear.

Common Loon breeds farther south than the others on wooded lakes across the northern United States and Canada, so it is particularly familiar to North American birders. It is a Hollywood favorite, and its call is frequently inserted into movie soundtracks to denote wilderness of any kind — often including, most inappropriately, the jungle! Common Loon's elegant features and distinctive voice lend it a mysterious and popular place in human society. Its likeness appears on the Canadian one-dollar coin, affectionately known as the "loonie." Indeed, the mournful wails of Common Loon are among the most moving sounds in the animal kingdom.

Hints and Considerations

• Common Loon is the default species inland or along the Gulf Coast. Red-throated Loon is rare inland, but common along both the Pacific and Atlantic coasts. Pacific Loon is rare inland and on the Atlantic Coast. Arctic and Yellow-billed loons are rarities anywhere outside Alaska, and scarce even there.

• Structure is key in loon identification, for all ages and plumages. Focus on the bill, head, and neck. Note the plumage pattern (light vs. dark areas) of the head, neck, back, and flanks.

• It is helpful to think about a mystery loon as belonging to one of two groups: "large loons" or "small loons." Generally, loons are big birds, but Common and Yellow-billed loons are especially large, with blocky heads, heavy bills, and robust bodies. In flight they flap more slowly than smaller loons (consider wind), have thicker necks and big feet, and at times hold their bills agape. The "small loons," Pacific and Red-throated, are slimmer overall and smaller billed, with sleek heads and necks. Arctic Loon falls somewhere between the two groups, with males quite large and heavy, and females approaching Pacific Loon in structure. Identify any putative Arctic Loon only with great care.

• All loons may "uptilt" their head or bill, but Red-throated, Yellow-billed, and Arctic loons do so most frequently. Common and Pacific usually hold the bill more horizontally.

• Immature loons wander more often than adults and are confusing, especially in summer, when feather wear, bleaching, and patches of adult breeding plumage confound identification.

Identification

Males and females are similar, but males average slightly larger. A loon's plumage varies depending on both season and age. In all species except Yellow-billed, breeding birds show black bills, while nonbreeding and immature birds have grayish bills with a darker culmen. Below, breeding plumage is described briefly first, followed by nonbreeding and immature plumages, as appropriate.

Adults are categorized as being in either breeding or nonbreeding plumage. Immatures attain adult appearance in the third fall, acquiring full breeding plumage in the third spring. Distinguishable plumages include: juvenile, first spring/summer, second winter, and second spring/summer. Second-summer loons appear highly variable, with some looking similar to winter adults, and others appearing similar to breeding adults but often retaining signs of immaturity (e.g., white blotches on face/neck). Second-winter loons are often indistinguishable from adults in the field.

While determining the age of loons is helpful in identification, all individuals are best identified based on structural characters, regardless of age. The species are ordered from smallest to largest.

RED-THROATED LOON: Our most distinctive loon, Red-throated is also the smallest and slimmest, with a small head and bill, and an almost serpentine appearance in the water. Only slightly smaller than Pacific,...