Ho, hum – more aliens...

Much has been made of the march of ring-necked parakeets across the British landscape in recent years. We are not alone: this burgeoning of their population – in some places exponential – has affected large tracts of Europe, particularly cities and crop-growing areas.

Forty Hall community vineyard in Enfield lost most of last year's grape harvest to them. Arguments rage over how many thousands are in these islands, and how we got into this mess, but one thing is certain: they are now present in almost every county of England, reaching into Wales and the Scottish Borders. Should ring-necked parakeets be culled? The rhetoric has been overtaken by the inevitable.

Their effect of competitive exclusion upon our own birds has been likened to the impact of the introduced grey squirrel on our native reds. It is not necessarily that the parakeets are overly aggressive (though a few instances of attacks on smaller species have been recorded), it's just that they are big birds and great opportunists that tend to go around in noisy numbers. They are phenomenally successful in their breeding, feeding and adaptation to new environments.

Garden feeders are one obvious key to their success. Large birds are naturally high in the pecking order at feeding stations, and these parakeets are omnivorous. They take seeds, grain, berries, fruit, nuts and even scraps of meat; samosas and fruit cake have disappeared with equal relish. Some say that their dependence on garden feeders, particularly in winter, is the reason that they are likely to remain as urban and suburban dwellers. But they still require holes for nesting and – apart from the odd outsized bird box, and there aren't many of those – that means a whole lot of trees.

Sherrardspark Wood would appear to be the perfect home for them, given the variety of woodland habitats and the great numbers of mature, ancient and veteran trees. Within these acres, previously crafted by natural damage, rotting processes and the jackhammer beaks of woodpeckers, ready-made holes await new occupants. So who stands to lose if they do invade? More research is needed to prove which woodland birds are affected, but the most vulnerable among them must be our breeding Stock Doves. Until now, these shy hole-nesters have bred quietly above our heads all over the wood, their mournful coo-ing the only clue to their presence.

Ring-necked parakeets are early nesters - often in January - so they can grab all available tree holes while other species are still only showing a twinkle in their eyes. Parakeets are regularly reported by residents whose gardens border Sherrardspark Wood. It was discovered that the birds gathered at Stanborough Lakes for roosting. Counts of the increasing population confirmed just how successful they are in our area: numbers peaked at over 500 in December. And yet a couple of miles away in Sherrardspark Wood sightings of them - mostly overflying - have been sporadic and not even in double figures at any one time.

In past years in Gobions Wood, to pick one example, I have seen substantial numbers of parakeets in residence, so why are they less interested in Sherrardspark Wood? The answer could be raptors! Buzzards maintain an aerial reconnaissance and keep watch deep within the wood every day. The sparrowhawk, a secretive but explosive hunter, is here too - a considerably greater danger to a parakeet. Both bred here in 2017. These birds of prey are the prize of any photographer, whether a professional or a rank amateur like myself, but if it turns out that their very presence makes them de facto protectors of our other woodland birds, we shall value them even more highly - and be forever in their debt.

Geoff Ralph

Wood warden

Photo Geoff Ralph

Parakeet meets woodpecker

Peak numbers of ring-necked parakeets roosting at Stanborough Lakes

Photo Geoff Ralph

Stock dove at a nesthole