Sunday, 22 June 2014

Seabird flight

Two Kittiwakes soaring over the sea
While visiting some seabird colonies on the Scottish coast recently I took a few images of the birds in flight to capture their comparative morphology and technique. For each has its own, which fits the species' life.

Herring Gulls have a heavy appearance 
Herring Gulls, like most gulls are more land birds than seabirds, for they forage onshore, often well inland, as much as at sea. Even when at sea they mostly inhabit coastal waters. So these birds have a generalist type of flight; they can soar and they can flap with deep strokes. They are recognisable by their strong, bulky body and thick set appearance.

Kittiwakes have a straight edged tail and bent wings even when gliding
Kittiwakes are true oceanic gulls. They are light buoyant fliers, only coming ashore to rest or nest. Most of their lives are spent foraging out at sea, where they glide, flutter and dip into the surface waters for food. These are delicate gulls, recognisable by their slender build. It is not so much their colouring or markings that identify them, but their agility and knack of switching from a long oceanic gliding flight to a tern-like fluttering dance, with their legs hanging down as they dip for food.

Fulmars have rounded tails and their wings are held rigid most of the time when flying
Fulmars are true seabirds. They spend most of their life on the wing, gliding on stiffly-held wings as they flip low over the waves. And they seem to fly more easily the stronger the wind. They might be clumsy on land when they come ashore to nest, waddling on their short weak legs as they scrabble onto their nest ledges. But those short legs are suffice for their purpose, when out at sea, they are an advantage, as they are tucked into the body feathers and never hinder the birds' aerodynamics. The whole bird is a slick flying form, using the wind for lift and thrust, and they are a delight to watch as they wheel around and around the airspace off the nesting cliffs.

Fulmars, like all petrels and albatrosses are true masters of oceanic flight
I have not mentioned the auks or shags which also breed on the Scottish coast, for they are more swimmers that fly, than flier that swim like the birds listed above. The auks' and shags' forte is their diving ability - they swim underwater.

No comments:

Post a Comment