SEA SIGNS

BIRDS

In the sixth instalment of our Sea Signs series William discovers what you can learn by observing the behaviour of birds.

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BIRDS

Watching birds is one of the greatest forms of meditation. Seagulls are perfect, because they are so plentiful; choose one and focus on it. Ignore everything else and concentrate wholeheartedly on your bird of choice. Follow its every movement, every duck and dive, twist and turn. Imagine the view as it soars high in the sky, feel the air flow past as it races down to the sea. After a few minutes – if you’re totally absorbed – you’ll notice your consciousness shift from your heavy, grounded self to the light, joyful and liberated bird. Not only is this meditative technique fantastic for de-stressing, it is practical too. By tuning into the behaviour of birds you’ll be able to access information invisible to the naked eye, like what the wind is doing or what the weather is about to do.

 

Birds have a receptor in their ear called a Vitali Organ that makes them highly sensitive to changes in atmospheric pressure. As a general rule, a rapid drop in air pressure indicates an approaching storm and birds can sense this, changing their behaviour to prepare for the bad weather. Changes include eating more to compensate for the loss of feeding time during the storm, and finding somewhere to take shelter. If you notice these patterns, check your barometer [I have one in my Suunto watch] and you should notice the pressure falling, with wind and rain following shortly after. And because the Vitali Organ makes birds so sensitive to atmospheric changes, when the air pressure is falling they fly lower to relieve the discomfort [because air is denser at sea level]. In contrast, when birds fly high it indicates high air pressure and better weather with clear skies and low winds. 

ANIMATION: SEAGULL

Because air is invisible, if you’re sitting in a shelter it can be very difficult to see which way the wind is blowing [unlike water, which clearly shows you the direction it is flowing]. A simple way to overcome this obstacle is to get into ‘meditative mode’ and observe how the birds are flying. Take-off and landing provide a clear clue because big birds generally do both facing into the wind; at take-off this increases the lift and for landing it controls the descent for a gentler touch down. Another flying technique birds use to save energy is to glide on rising air caused by the wind being deflected upwards by a solid object like cliff face, hill or man-made structure. This is called a Ridge Lift, or Orographic Lift. On Deal Pier, where I used to write in the mornings, seagulls would soar along a Ridge Lift on the southern side of the walkway where the southerly wind is deflected upwards by the pier wall. In contrast, when birds glided up and down the northern side of the walkway it meant the wind must be coming from the north.

“birds generally take-off and land facing into the wind”

Birds’ feeding habits are often dictated by the tides and currents, so observing their behaviour can tell you a lot about what the water is doing. This is accentuated in the dramatic ecosystem of the Corryvreckan whirlpool on Scotland’s west coast where intense changes in the currents speeding up and slowing down every six hours provides unique opportunities and dangers for birds with specific skill sets - or limitations. 

 

Cormorants, who can only swim 2 metres a second [half the speed of the currents in the main channel] sensibly stick to slack water, then retreat to slow-moving eddies when the currents speed up. This is when the auks and kittiwakes enter the scene, revelling in the racing water. But this doesn’t last long and a few hours later the Guillemots arrive, a sign of the approaching slack water and an opportunity to swim the 1km wide strait - if you’re that way inclined. But you’ve got to be quick because the increasingly powerful currents soon create whirlpools capable of sucking a swimmer 150 metres beneath the surface.

PRODUCT VIDEO: BIRDS

A gentler environment to observe birds is the marshes of North Norfolk, a twitchers paradise. My favourite stroll here is from Burnham-Overy-Staithe, where a raised walkway winds through the tidal inlets before becoming engulfed in the sand dunes. Beyond there, waders such as oystercatchers, grey plovers, knots, dunlins, bar-tailed godwits and curlews feed in the expansive intertidal zone at low tide. 

 

But the flood tide pushes them further and further up the beach until they are all forced up into the air. This dramatic display marks the impending high tide, and their return to the feeding grounds lets you know the peak of the tide wave has passed and water will be receding for the next six hours. This is a perfect moment to head out because it gives you the maximum time exploring before the next flood forces you and the waders back to the dunes. 

ANIMATION: BIRDS TAKING OFF AS THE TIDE RISES

Before the days of charts and compasses, ancient explorers used birds to help find land. At the same time that the Polynesians were using frigate birds to locate tiny islands in the vast Pacific Ocean, Viking marauders were using ravens to help them find the British Isles. When the captains sensed land was close they would release a raven; if it circled the boat then settled back on-board they knew the coast was still a way off. But if the bird flew determinedly in a particular direction, the sailors would alter their course and follow the raven in their search for pillage and plunder. They also kept an eye out for birds - especially Terns and Boobies, that they knew fished within a 25-mile radius of land. So if you ever find yourself swept out to sea with no land in sight, keep an eye out for the birds because they’ll lead you to safety.

In the next Sea Signs feature William will explore how you predict the sea conditions by observing the wind.

About this series

Every day the sea is different, a  result of the ever-changing interaction between the moon, sun, tides, wind, waves,  buoys, boats and the beach. While the picture may appear complex, like a piece of classical music, it is essentially just an arrangement of simple elements, or notes. By dismantling the machine into its component parts and exploring each one in detail we can create order out of chaos; clarity out of confusion. That is the  purpose of this series 'Sea Signs'.

When we are young we learn to navigate urban environments; what traffic lights  mean or how to cross a road. What many of us aren’t taught is how to read nature’s  signposts; how to judge wind by watching birds or what weather different clouds  bring. Then there’s a whole technical world of buoys and boats with different light  sequences, colours and signals communicating messages. My goal in this series is to  share with you all the signs – both natural and man-made - that you may encounter in  your adventures along the coast so you can read them as well as any yachtmaster  skipper or crusty old seadog. 

With this knowledge, nothing is going to slip under your radar.