December is a good month to see our smallest duck

There is something rather special about a visit to the North Norfolk coast at this time of the year. The coastal marshes and flooded pastures support huge numbers of wintering wildfowl, and it is quite something to see and hear the feeding flocks of ducks and geese. Such winter visitors include the diminutive teal, our smallest native duck and one of my favourite birds. Its clear, ringing whistle is such a characteristic sound; shorter and with a harder edge than the soft whistles produced by the wigeon alongside which teal are often found. Flocks of at least 1,500 individuals may be seen at Cley, while another Norfolk Wildlife Trust reserve, Hickling Broad, regularly supports up to 3,000 birds. Far smaller numbers of teal occupy waterbodies that are situated well inland. However, I have seen them on the Breckland meres and on smaller pools spread across parts of the southwest of the county.

Although small numbers of teal breed in Norfolk, our wintering population is largely drawn from birds that have bred in Iceland, Scandinavia, the Baltic States and east into Siberia, making Britain an internationally important site for the species. Other teal winter as far south as North Africa and up the Nile Valley.

Watch a flock of feeding teal and it soon becomes apparent that they favour shallow water, dabbling to feed on the seeds of aquatic plants (these make up some 75% of the winter diet) and small invertebrates. In some areas, though, they have taken to using winter stubbles. This reliance upon shallow water makes them vulnerable to severe winter weather. Low temperatures and the freezing over of the shallows drives the birds to undertake cold weather movements, taking them further south and west in search of open water. Such movements usually drive our birds down into western france and Spain, where they occupy sites that are only important when the weather is particularly bad further north. Although a quarry species and popular with waterfowlers, temporary bans on shooting during severe weather help teal to feed on unfrozen waterbodies in relative peace. This can make an important difference to birds that are energetically stressed and needing to maximise food intake.

Assuming that we do not get a hard winter, then many of the teal presently in Norfolk will remain here until at least the end of February, when the spring departures begin. Since the spring migration is something of a protracted affair, many of the birds will still be here in late March or even early April. Arrivals back on the breeding grounds, and indeed the breeding grounds chosen, will depend on local weather conditions, again highlighting the fluidity of movements shown by this delightful species.