Sea or Land Birds?

The wildlife that surrounds us is full of fascination and it is always worth checking out guides, books or the internet for information about what lives on our doorstep. Recent reading has revealed some interesting facts about birds that are perhaps more commonly, if erroneously, associated with our coasts.

Various species of gull spend a lot of time on the Sudbury riverside including black-headed, common, herring and lesser black-back depending on the time of year and weather conditions. So to call these gulls ‘seagulls’ would, of course, be inaccurate. Gulls are opportunistic feeders and are equally at home following fishing vessels for ‘discards’, the farmer’s plough or cultivator for worms or tearing through fish and chip packaging at our seaside resorts. They could be described as living at the interface between land and sea from where they can decide where they might most profitably go in search of their next meal.

Another bird that may have been more strictly associated with our coasts is the cormorant – the bird that many love to hate. Climate change affecting ocean currents and water temperatures coupled with overfishing have encouraged the adaptable cormorant to take to inland rivers and lakes, swapping diminishing sea fish for their freshwater cousins.

Unlike gulls which are predominantly white, the cormorant has an oily black appearance. The bad press which extends from the time of the ancient Greeks through to Shakespeare and to the present portrays them as the ‘enemy’. Perhaps this arises from their habit of holding out their wings motionless to dry after fishing when they do look disconcertingly evil. The reason for this is that cormorants have evolved very little from ancestral birds of one hundred million years ago and still have a primitive plumage. Their wings are large and quite an encumbrance under water so in order to dive deep for their fish prey their feathers are open enough to allow water between them in order to reduce buoyancy. It would be natural to assume that the birds seen with outstretched wings are drying-out following a fishing expedition. However, it is now thought that the posture may be adopted in order to aid digestion. The reduced buoyancy aided by water between the feathers is very noticeable when cormorants swim as they sit so low it gives them the appearance of sinking as water washes over the base of their necks.

The Chinese have traditionally used cormorants as fishing birds as they are intelligent enough to be trained for this role. One fisherman may have several birds on his boat and use them in turn to catch fish for him. Presumably on account of their use as fisher birds the Chinese do not revile them as western culture does so perhaps we have missed a trick there. Either way, a cormorant or two sitting with outspread wings, either to dry or digest, in the trees opposite Friars Meadow brings a touch of another world to the Sudbury riverside.