02 Nov Newburyport Birders’ Update – November & December – 2017
Fall migration is well underway! Recently, at Salisbury Beach State Reservation, skeins of Double-crested Cormorants filled the overcast sky. Their loose flocks looked like calligraphy. Common & Red-throated Loons are on the wing. Horned Larks are foraging in the wrack line and on grassy strips. Brant are being seen. Hopefully, Snow Geese will be headed our way soon. Ruddy Ducks, Buffleheads, Ring-necked Ducks, American Coots and Pied-billed Grebes are on ponds and reservoirs. Snow Bunting migration will be underway in the next few weeks. PetiteNorthern Saw-whet Owls are heading south. The crespuscular Short-eared Owls are hunting over the marshes.
Pied-billed Grebe – “Water Witch”
Grebes have tiny, saw-like teeth on the edge of their bill which aid them in feeding on aquatic invertebrates, vegetation, insects, fish and frogs. This chicken-like bird is usually absent from our landscape from the middle of December to the mid-March. In late fall, they migrate south where it’s certain to be more hospitable. Veit and Petersen’s “Birds of Massachusetts” reports Pied-billed Grebes are first “irregular in winter” and secondly, “During mild seasons, when ponds and bays remain unfrozen, Pied-billed Grebes are capable of surviving the entire winter in Massachusetts. Most birds are found on Cape Cod and the island, but there are midwinter reports from inland localities…”
Grebes compress air out of their feathers and air sacs by contracting the firm and toned abdominal muscles which regulate their buoyancy and shape. Their plumage is satiny and well preened. They are similar to coots and phalaropes in that their toes are lobed and each toe has lobes extending out on the sides providing extra surface area for paddling. The grebe’s tarsi are laterally compressed.
Highly designed for water with legs set far back on the body like “divers”, grebes are efficient waterbirds. They’re gawky on the solid part of the earth’s surface when they come to land to nest.
I once watched a grebe as it bathed and preened in the sun against a wall of peat while I peered through my scope. I watched as it used its bill to obtain oil from its oil gland. Grebes are often described as tail-less, and Proctor & Lynch’s “Manual of Ornithology” refers to the tail of the grebe as vestigial.
Gill’s “Ornithology” mentions “…grebes have high wing loading. To take off,they must run over the water, flapping their wings to gain enough lift for flight.” Lots of energy is expended to take flight; an apprehensive grebe will dive, sink or swim to escape predators. Once while foraging in vegetation, a grebe sunk and revealed only its bill above water; I thought of a submarine, a ship that can operate both under and on top of the water, and that bill was the periscope.
I read in Alexander Wetmore’s “Water, Prey and Game Birds of North America” that grebes eat their own feathers. Wetmore states “Strangely, grebes eat their own feathers, retaining them in their stomachs in a tight ball until they disintegrate enough to pass through. The clumps may hold back such objects as fish bones until they are soft enough to digest.” Wetmore, a past president of the American Ornithologist’s Union, lists the Pied-billed Grebe’s monikers as “hell-diver, water witch and dabchick”.
“The Sibley Guide to Bird Life and Behavior” notes “The feathers may protect the stomach from puncture by indigestible parts of the grebe’s prey and prevent hard items from entering the intestines. They also provide the base material of regurgitated pellets that contain undigested material such as fish bones.”
Buffleheads Rely on Northern Flickers and Pileated Woodpeckers
I’ve heard duck hunters refer to Buffleheads as “Butterballs”. It’s Butterballs’ diving that forces me to stop and linger, to observe for understanding. I watch the thrusts, leaps, propulsion and buoyancy. Their plumage is pulled tight into their body; then, with a thrust of power and a slight, forward, nearly upward leap, they plunge. Their pink legs and feet force this propulsion. Upon surfacing, they bob cork-like on the surface like a tiny toy used to lure a reluctant toddler to its evening bath.
The smallest of the diving ducks native to North America. They are sexually dimorphic both in plumage and in size. Drakes just exceed a pound in weight, and the hen, even smaller, weighs in at three-quarters of a pound. They’re agile swimmers and divers. On land, they’re awkward with legs set well back on their bodies.
I’ll never tire of these buoyant, petite ducks ~ the ones that fly low over water and then higher over land. These black and white ducks are fast in flight with rapid wing beats without even a whistle. They are one the fastest waterfowl and are easily recognized by their small size, large head and flight cadence.
While a flock is diving for food, there’s almost always at least one sentinel on the surface alert to danger. I see them divide their time between shallow dives and rest periods on the surface. I’ve timed their dives ~ they stay under 10 – 14 seconds. After the dive, they surface, and their bills are prey less since they consume their prey while underwater. On freshwater, they eat mostly insects, and in waters of salinity, they feed predominantly on crustaceans and mollusks. Aquatic plants and fish eggs are often on the menu too. Once during the shorter, harsher days of winter, I saw some foraging even after dark.
On the water, when lighting permits, Buffleheads create stunning reflections of symmetrical beauty. They have dark-chocolate, brown eyes. Drakes are white with a black back, and their black head has a greenish to purple iridescence and a large, white patch from behind the eye to the top and back of the head. The dark hen sports a single, almond-shaped, white patch behind the eye.
Buffleheads have a woodpecker and boreal forest connection. Buffleheads nest almost exclusively in cavities excavated by Northern Flickers and Pileated Woodpeckers. The breeding range of the Bufflehead is restricted to the woodlands of North America. The vast majority of Buffleheads breed in boreal forests and substrates studded with aspen.
The Bufflehead is shy and mostly monogamous, often remaining with the same mate for several years – an admirable trait in today’s world of short-term commitments. The hen lays eggs at a slower interval than most other ducks, commonly with intervals of two or three days between eggs.
As I study Buffleheads in local rivers, sheltered waters of Ipswich Bay or the Plum Island estuary area each winter, I think of the importance of the Northern Flicker and the Pileated Woodpecker and their excavating skills. The intertwined threads in nature continue to amaze me. When one pulls one thread, others unravel…
With best wishes,
Observe ~ Appreciate ~ Identify