BuffleheadBucephala albeolaKde a kdy je můžete spatřit

The Bufflehead is a compact diving duck with a disproportionately prominent head and a distinctive contrast between male and female plumages. Males can look strikingly black and white at distance, while females are darker and show a smaller pale cheek patch. Cornell describes an important ecological connection to woodpeckers: nesting cavities are commonly old Northern Flicker holes, small enough to exclude larger cavity-nesting ducks. The registered river associations are Umatilla National Wildlife Refuge and the John Day pool on the Columbia, and the Upper Mississippi River refuge corridor from Wabasha to Rock Island. These are separate local evidence problems. The Upper Mississippi refuge explicitly mentions Bufflehead among mixed diving ducks, while the Columbia registry association requires its own seasonal verification. Neither should be treated as proof of local breeding, and neither allows a national migration map to substitute for reach-specific viewing advice.

Size

Not independently verified for this draft

Weight

Not independently verified for this draft

Lifespan

Not independently verified for this draft

Status

See sourced assessment

Bufflehead repeatedly dive while feeding, often disappearing for short intervals and resurfacing nearby. Cornell notes that prey is commonly swallowed underwater, so a visitor may observe a successful feeding sequence without seeing an item in the bill. This distinguishes the experience from watching a heron bring a fish above the surface. Small groups can be easier to follow than large mixed rafts, although mixed flocks provide useful size comparisons. Nesting behaviour is quite different from open-water feeding: the species uses cavities, especially those excavated by Northern Flickers. That dependency belongs to its breeding ecology and does not establish nesting in either registered river reach. Watch voluntary dives and resurfacing without approaching until birds repeatedly abandon feeding. A vessel’s movement can shift a flock even when no obvious alarm call is heard. Allow space around resting and feeding birds and respect refuge closures rather than following them into sheltered areas.

• It is a diving duck.
• Food is often swallowed underwater.
• Freshwater prey include aquatic insect larvae.
• Snails and clams can also be eaten.
• It commonly uses old Northern Flicker nesting holes.
• Small cavities can exclude larger competing ducks.
• Males and females have different head patterns.
• Sheltered inland river bays can provide habitat.
• The Upper Mississippi source supports a qualitative autumn association, not exact months.

The Upper Mississippi refuge’s birding guidance names Bufflehead among ducks that may occur together in its autumn diving-duck discussion. This supports a qualitative local autumn association, but the reviewed species passage does not provide a defensible numeric month range, peak date or guarantee for every refuge unit. The Mississippi location therefore retains empty months while explaining the qualitative evidence. For Umatilla, the official refuge page discusses protection of wintering waterfowl generally, not Bufflehead specifically. That general statement cannot establish Bufflehead winter months, and county-wide eBird dates are geographically broader than the registered refuge reach. The Columbia location also retains empty months. Cornell’s range-wide migration descriptions remain background biology rather than a substitute calendar. Ask each refuge separately about recent observations, ice or water conditions and accessible viewpoints. A seasonal tendency is not the same as a precise forecast for a particular cruise departure.

Cornell describes breeding near ponds and lakes in boreal forest and aspen parkland, with cavity availability important to distribution. Outside breeding contexts, Bufflehead use sheltered coastal water and inland ponds, lakes, impoundments and bays along slow-moving rivers. That inland description is relevant to both registered corridors, but it does not identify an occupied pool. On the Columbia, the registry specifies Umatilla refuge and the John Day pool near Boardman–Irrigon. On the Upper Mississippi, refuge backwaters and accessible river overlooks provide a more precise habitat framework than the river name alone. Exposed fast water is not equivalent to a sheltered feeding bay. Ask refuge staff which legal viewpoints currently overlook suitable water and whether birds are being seen there. Do not infer nesting from proximity to trees, and do not assume every protected island is accessible simply because it appears close to a public boat route.

Cornell provides unusually detailed feeding information for this species. Bufflehead dive for aquatic invertebrates, crustaceans and mollusks, and freshwater foods include insect larvae, amphipods, snails and clams. Some plant material is also taken in parts of the annual cycle. Marine prey listed in the same account should not automatically be assigned to birds feeding in Columbia or Upper Mississippi freshwater. The underwater swallowing habit explains why the diet is not easily reconstructed from casual surface observation. A succession of dives demonstrates feeding effort, not the identity or number of prey captured. No reach-specific prey-frequency study was verified here, so local dietary proportions remain unknown. Observe from a stable viewpoint and avoid throwing food or disturbing bottom sediments to attract ducks. The relevant conservation feature is a functioning shallow-water food resource, not a manufactured concentration beside a boat.

Common name

Bufflehead

Scientific name

Bucephala albeola

Animal group

Birds

Size

Not independently verified for this draft

Weight

Not independently verified for this draft

Lifespan

Not independently verified for this draft

Status

A current formal global conservation assessment was not independently verified for this draft.

Identification

A male Bufflehead combines a compact body with a large-looking head and a conspicuous white head patch contrasting with dark iridescent areas. At distance the iridescence may simply appear black, so the pattern and proportions matter more than seeing a particular sheen. Females are darker overall with a smaller pale cheek patch. Repeated diving is a supporting behavioural clue but is shared with several other ducks. Compare head shape, bill proportions and the placement of pale areas rather than identifying every small black-and-white diver as Bufflehead. Mixed flocks can help establish relative size, though birds at different distances should not be compared directly. Cornell’s cavity-nesting information is not an identification feature for a distant waterbird and should not replace visible characters. If glare obscures the face, wait for a change in angle rather than forcing a confident answer from a silhouette.