RSPB Mersehead blog 28th August – 3rd September 2021

September has arrived and signs of autumn are appearing. The nights are noticeably drawing in, the evenings are cooler, leaves are turning golden and birds are flocking together.

Warm and sunny days have continued and keeping one keen eye on the vegetation can reveal some brightly coloured and fascinating finds. The caterpillar of the Knot Grass moth is bright and bold in its colouration as a defence against predators. The adult moth this caterpillar will develop into however is a much quieter shade of mottled grey and black.

Often described as stingless wasps, Sawflies don’t have much of an identity to call their own. The adults resemble flies or wasps but are neither whereas the larvae look much like a caterpillar but is not. If the larvae are all feeding along the margin of a leaf and rear up when disturbed this is a good behavioural characteristic.

According to reserve records the first Purple Hairstreak for the reserve was recorded this week by the Assistant Warden. This species is found on oak trees and favours fluttering high in the canopy and so can be tricky to spot and in all likelihood has been present on the reserve a long time without being noticed. On this lucky encounter the butterfly not only flew low enough for a good view, it even posed for a photograph.

Britain’s heaviest spider, this Four Spot Orb-Weaver Spider was caught hitching a ride on the tractor. Colour can vary from dark brown to yellow-green or bright orange however they always have banded legs. In a competition for extremes, Britain’s longest dragonfly was recorded this week. The Golden Ringed Dragonfly is a striking black insect with yellow bands and is a voracious predator. Breeding along acidic streams on moorland and heathland this dragonfly is more commonly seen at Mersehead throughout September.

The sunflowers in the wild bird cover plots are in full flower and attracting an assemblage of insects and bees.

The spring oat crop was combined this week creating the habitat over-winter stubble which will provide a winter food source for seed-eating birds through spilt grain and the seeds of broad-leaved weeds. This is one of the fastest declining habitats in the agricultural landscape and the loss of this food source has been directly linked to the decline in farmland birds. The oats have been attracting a number of migrants with Whinchat seen again this week. A lone Tree pipit was spotted feeding on the ground whilst 2 Willow tit were seen flitting along the hedgerow.

The Lesser Whitethroat was seen again this week from the comfort of the sofa. This species has taken the Mersehead year list to 129. A great end to the week was a fly over Osprey.

Rowena Flavelle, Warden