Watch a starling roost at dusk and you could see a sparrowhawk lurking with evil intent, says Pip Webster
Will it be a ‘snow bird’ winter?
Blackening through the evening sky, In clouds the starlings daily fly, To Whittlesea’s reed-wooded mere, And osier holts by rivers near” comes from John Clare’s evocative description of fenland in January. (An osier holt is a place where willows are grown for basket making.)
When starlings assemble in flocks it is said to be a sign of cold weather. Before the early 20th Century starlings were seen only as winter visitors in south-west England and Wales. Moving ahead of the colder weather, they were known as ‘snow birds’ in parts of Wales where locals regarded their arrival as a sign of impending snow.
Grassland is their favourite habitat and you can often see large flocks of resident starlings, boosted by winter migrants from north-east Europe, probing grass roots for invertebrates such as earthworms and leatherjackets (the larva of craneflies – better known as daddy-longlegs).
In the evening, flocks combine into even bigger night roosts of thousands of birds, a favoured location for starlings being over water in reedbeds where the air temperature tends to be slightly higher. The combined weight of the birds can eventually flatten the reedbed.
If your narrowboat is moored close to a “murmuration” of starlings, you will get no peace until silence suddenly descends. Individual birds are excellent mimics and the creaky quality of their song gave rise to the old Norfolk name of “wheezer”.
The beautiful purple and green iridescent plumage of starlings is less marked in winter months since they develop dense white or buff arrowhead-shaped spots in the autumn which gradually wear away through the winter. During winter and spring the sex of Starlings can be distinguished by the colour of the base of the bill: appropriately, pink for females and blue for males!
If you watch a starling roost at dusk you may see a sparrowhawk lurking – with evil intent. Unlike the more common kestrel, sparrowhawks never hover, but adopt a “guerrilla”-style hunting technique: a regular tactic is to accelerate along one side of a hedge, then flip over the top and grab the prey with long talons. They will even take young moorhens from off the water.
Their long tail feathers and short rounded wing profile are designed for manoeuvrability and the lack of leaves in winter makes their short hunting bursts easier to observe. The unfortunate captive is plucked before being eaten.
The male, our smallest raptor, is a handsome creature: slate-blue-grey above with rufous-barred underparts. In the age of falconry, the “musket” was a hawk for a priest; the name subsequently being used for a type of crossbow bolt and then a hand gun.
The sexes exhibit the largest size difference of any raptor, the female being twice as heavy with duller, browner plumage – and she takes larger prey.
Low-flying, agile hunters are more easily spotted by several pairs of eyes, and this is the prime reason that smaller birds gather together into mixed flocks in the depths of winter.
Looking at the bare branches of winter trees and hedges along the towpath, you may wonder where all of the birds have gone. A sudden chatter of activity, and a mixed flock of tits, finches and other small birds seems to be feeding all around you before they just as quickly move on – a ‘bird wave’.
Competition for food is not as great as you might think since each species has a different feeding niche: great tits work through the leaf-litter on the ground, greenfinches pick the seeds out of fruit, and the tiny long-tailed tits hunt for insects high in the mesh of thin twigs at the top of the canopy, their long tails providing a counterbalance for their acrobatics.
With eyes at every level, sparrowhawks are more likely to be seen and alarm calls are even recognised as such by we humans. The flock scatters, disrupting the concentration of the hunter.
Keep safe this winter.
‘Individual birds are excellent mimics and the creaky quality of their song gave rise to the old Norfolk name of “wheezer”’