7 June 2015

On the trail of the red squirrel

Squirel (Sciurus sp.) eaten spruce in the grounds of Haddo House. Some cones appear to have been subsequently eaten by wood mouse (Apodemus sylvaticus

With some time to spare yesterday in the grounds of Haddo House, I opportunistically found a quiet looking path adjacent to a tree plantation to slowly creep past looking for wild mammals and their field signs.

There is a very obvious clue to amateur trackers of any skill level that red squirrels (Sciurus vulgaris) use the grounds at Haddo -  there are road signs along the drive to the car park which state "Kill your speed NOT a red squirrel."

Following a mammal path under a canopy of spruce trees (with the occasional beech tree), I quickly found an abundance of spruce cones which displayed clear squirrel feeding signs on the woodland floor and on tree stumps.

Squirrels like to sit on a tree stump or mound whilst eating for a good view for predators. Around a third to half of the cones were found on top this stump already, whilst the others were found within around 1.5 metres or so around the stump and placed on top of the stump for the photo just to give an impression of the density of feeding signs in one small space.

Some of the spruce cones  have probably also been eaten by another species after the squirrels! Cones which have been fed on by squirrels alone have frayed ends where the scales have been removed. Wood mouse (Apodemus sylvaticus) will often feed on the cone after the squirrel, removing ragged and frayed ends and removing the tip of the base of the cone leaving a rounded base. The mice often move the cones to a more concealed place to feed on them.

Encouraged by the abundance of squirrel feeding signs, my attention changed from looking at the ground to looking into the canopy for squirrel dreys (their nests). Dreys are constructed from twigs and leaves and are almost spherical (or flattened to be wider than tall). They are usually around 25 to 50 cm in diameter (football size and larger) and normally found against the trunk of the tree (held up from where a branch leaves the trunk) from around 6 metres above ground upwards, though they can also be at a fork in branches.

The darker object is approximately football sized and is a squirrel (Sciurus sp.) drey. Seen in the grounds of Haddo House

The squirrel (Sciurus sp.) drey is the darker object behind many living branches and twigs in the forefront. Seen in the grounds of Haddo House

Crow and magpie nests can be superficially similar in appearance but tend to be found further from the trunk and are usually made of dead twigs without leaves.

A squirrel may use three, four or occasionally more dreys in their territory. Reds and greys are both also known to use more open saucer like dreys during the summer as resting places. I could not decide if another structure that I saw in the woodland was one of those or just an old drey which had started as a spherical form and fallen apart.

Red squirrel (Sciurus vulgaris) and grey squirrel (Sciurus carolinensis) feeding signs cannot be told apart and there are no obvious and reliable differences in the appearance of their dreys to tell them apart. Both species may even use the same drey at different times!

Unfortunately the strong wind at the time of the visit made detecting squirrels themselves difficult and survey guidance suggests that they are less active in those conditions anyway. I will take the word of the road signs on the drive and presume that I was looking at the field signs of red squirrels.

Saving Scotland's Red Squirrels is an award winning partnership project led by the Scottish Wildlife Trust and includes Scottish Natural Heritage, Forestry Commission Scotland, Scottish Land and Estates and the Red Squirrel Survival Trust. It is directed at conserving our native red squirrel and managing the grey squirrels which threaten the reds through competition and disease. SSRS welcome records of sightings of both species to help target efforts where they can make the greatest difference.