One of my favourite birds on Arran is the Wren.  It is among the most widespread of birds on the island and is found from the highest peaks to the shore.  It is one of the most adaptable birds found in a wide range of habitats.   It is almost the smallest bird in Scotland.  The Goldcrest is smaller as measured by body weight, but the Wren must have the longest scientific name Troglodytes troglodytes troglodytes.  Troglodytes comes from the Greek meaning “to creep into holes” and that does describe its behaviour.  For such a small bird it has one of the loudest songs.  Also despite its diminutive size British-ringed wrens have been recovered in southern France.  Scarcely believable is the globe-spanning individual ringed in Sweden and eventually found in southern Spain! 

The new “Birds of Scotland” estimates the total number of occupied territories to be around 1,400, 000, and in winter the Wren population may reach 8,000, 000, although cold winters can decimate their numbers.

They have a survival technique.  While during the day Wrens are not particularly sociable, they regularly pack into roosts soon after sunset during the winter.  They may continue this habit until the last week in April. Most favoured sites include old house martins' nests, nest-boxes and holes in walls and under roofs. This behaviour helps the birds to survive harsh winter conditions when many birds do succumb to the cold.

The human occupants of one home in Blackwaterfoot have put up a roosting pouch and now have the pleasure of watching a string of Wrens piling into this little shelter each evening.  Over a fifteen to twenty minute period on cold or particularly inclement winter days, the wrens dart up and down the house walls or between the roosting pocket and one of the old House Martin nests nearby.  They seem to start seeking cover just before dusk. Gradually they settle down inside. Numbers are difficult to determine but during severe weather in Norfolk, one nest box roost held sixty Wrens.  Some roost sites are traditional, drawing birds from more than a mile away.  Once inside, roosting Wrens squat up to two or three layers deep with heads facing inwards and tails towards the entrance or sides.  If you would like to help these delightful little birds through the winter consider putting up a roosting shelter in a dry spot away from predators.