10-Jan Spotting Rare Birds

The latter two birds are always impressive and exciting to encounter. They are both sawbills on account of their long, tapering beaks which are edged with backward-pointing ‘teeth’ and end in dangerous-looking hooks. They are also both strikingly coloured with long necks and long streamlined bodies that seem to sit far too low in the water.

They can at times be difficult to separate, especially when they spend time together on reservoirs in winter. It is always worth looking carefully at their heads. Both males have bottle-green heads but the goosander has a much more noticeable crest and the merganser a much bloodier eye. The heads of the females are more rufous in colour and both have crests, but only the female goosander has a prominent white chin.

Both birds are cautious, distrustful and likely to be just passing through London. If they do stop over they prefer the quietest stretches of water on certain favoured reservoirs such as Staines and Wraysbury. Here they seem to spend most of their time floating or sleeping, occasionally lifting their impressive crests in display.

The river Thames is always a good place to look for rarities. Slavonian as well as black-necked grebes at this time of year regularly make an appearance. Wraysbury, Lea Valley, Colne Valley and West Thurrock are also good places to look for them. Other rarities recorded include ring ouzel, Lapland and snow bunting, twite, great northern diver, white-fronted goose, long-tailed duck, pomerine skua, Leach’s petrel as well as the so called ‘white gulls’ i.e. the . Mediterranean, glaucous and yellow-ringed gull.

Rare visitors to reedbeds now are bearded tits and penduline tits. The bearded tit was also called the reed pheasant on account of the way it flies, which looks not unlike like a miniature pheasant. Occasionally there is an ‘irruption’ in its eastern strongholds and it is then that some tend to turn up in London. Similarly, the penduline tit seems to be expanding its range across Europe with one or two regularly turning up in places such as Rainham Marshes.

Other rarities come from as far afield as Scandinavia, Iceland and even Russia. It seems likely that some birds now scarce, were a lot more common in the past e.g. bittern, black-throated diver, green sandpiper and bar-tailed godwit, all of which regularly were found on the menus of medieval banquets.

In some years up to as many as eleven thousand have flown across the North Sea from Scandinavia when the rowan berry crop there has failed. Here they seem driven to other species of rowan with larger, brighter berries. Up to forty or more may stay in a single tree for almost a week as they did in Balham in 2010. Such sights have an unreal quality for the lucky viewer. In its Arctic taiga home it chatters, consequently also enjoying the name of the Bohemian chatterer but here they are almost always silent. The years they do appear they have been reported as centrally as Warren Street as well as the occasional supermarket car park in the East end.

They collect in such places taking advantage of the bright berries on widely-planted shrubs such as Cotoneaster and Pyracantha. Word generally gets about if they have arrived and birdwatchers all over London come to see them. Fortunately they seem oblivious to human company allowing people to stand close to the trees on which they are feeding. If close enough it is worth attempting to count the number of signal red tips on their wings. If there are eight it is likely to be a dominant male, if only four a female or perhaps a juvenile. If they do get disturbed, they all fly off together at high speed in a distinctive close ‘red arrow’ style formation.