Observations in the Haslemere area - week ending 25/8/24.

The wet weather through most of the year is a plausible reason for the widely-reported drop in butterfly numbers, which now seems to be affecting the late summer fliers. However, it can hardly be blamed for the poor summer season for fungi: there are normally plenty of brittlegills (Russula species), amanitas and boletes whenever there are wet spells in July and August, but woodland floors have been nearly bare this year, apart from the ubiquitous Common Earthballs. Just a few scrappy fungi were found following rain this week.

Swallows are still present, sometimes accompanied by predatory Hobbies, but they will soon be gone. Ospreys have been seen heading south in various places in southern England, including one reported at Shackleford this week. Yellow Wagtails and Ringed Plovers were reported passing through Thursley Common.

Among the typical late summer butterflies, Grayling and Small Copper have been seen, but nymphalids (such as Peacock and Small Tortoiseshell) are still sparse. One line of investigation into the varying success of butterflies is the life stage in which they over-winter: perhaps those over-wintering as chrysalises (such as most of the whites), rather than as eggs or caterpillars, have fared better. Moth numbers are down, but a few species have had boom years: Jersey Tigers, Light Crimson Underwings and Gypsy Moths in particular. Gypsy Moths have until this year been rare: there was a UK subspecies in East Anglia that became extinct in 1907, and there have been occasional migrants across the Channel since the 1950s, but it is now clear that the species is breeding in southern England. Locally, numbers started increasing in 2019 and this year it seems to be everywhere, and never before so abundant in the UK. Other interesting moths this week were Treble-bar, Pale Eggar and the micromoths Pandemis corylana and Ypsolopha sequella.

A tiny rodent rescued from a pool, where it had probably evaded a predator, resembled a Harvest Mouse, but an expert’s verdict was that it was a young vole. It is, nevertheless, a good time to look for Harvest Mouse nests, which are tennis ball sized hollow spheres of dry grass attached knee-high to tall grass stems, often around field edges.

Interesting late summer flowers included Carline Thistle and Common Fleabane. As the name suggests, Common Fleabane was once used as a flea deterrent, but, curiously, although some closely related species contain the insecticide pyrethrin, Common Fleabane does not have it in functional concentrations.

(These observations and photos have been compiled principally from postings by Haslemere Natural History Society members to the Members’ Facebook group).