By Denis O’Connor, Wharfedale Naturalists Society

THERE is a constant stream of birds to the feeders in our back garden, with dozens waiting their turn in the hedge before darting in to snatch sunflower seeds or spend brief periods attacking the fatballs.

The birds are nervous and with good reason for, although the distance between hedge and feeders is short, it provides scope for the most feared visitor, a male sparrowhawk which shoots by on different trajectories several times a day.

It usually misses although at times it is travelling so fast that it is hard to tell whether or not it has hit its mark.

I had not seen it with a kill for months until a few weeks ago when it was crouched on the grass plucking a blue tit (pictured) before flying off leaving behind a rough circle of fluffy blue, white and yellow feathers.

The feathers were still there until dark but, although there was no overnight breeze to disperse them, they had completely gone by daybreak.

The point from which they had vanished was close to the hedge, at a spot from which I have recorded both wood mice and bank voles emerging to collect scattered sunflower seeds.

Both these tiny mammals are essentially nocturnal and are seldom seen by day but often appear on a trail camera set up overnight as they take the opportunity to feed but probably also to replenish their food reserves, behaviour that with the wood mice continues even on frosty subzero nights.

When seen by day the wood mice have noticeably huge eyes while the voles have eyes like black buttons, but at night the trail camera picks them out in black and white with eyes reflecting back the light so the eyes of both appear like tiny headlights.

The mice are still identifiable by their big ears and long tails. The voles by contrast have scarcely visible ears and shorter tails, only half the length of their bodies.

Both species construct underground burrows that include food stores and nest chambers although both sometimes build nests above ground and wood mice at times move into sheds and houses where they are often mistaken for house mice.

I suspect that the feathers from the unfortunate blue tit were spirited away to provide extra insulation for a mouse or vole nest chamber at a time of year when such extra help in keeping warm would be especially welcome. Nature rarely wastes useful materials.

wharfedale-nats.org.uk