After a dry August (the first 'dry' month for nearly a year), September started unsettled, with a few rain showers and very variable temperatures, which peaked at 28C on the 1st. Royston is in one of the driest areas of the country, and this was emphasised as we missed torrential rain to the south in the first week and the constant battering of wind and rain that was endured in north-west Britain at the end of August and early September.
September sees bird migration through the country, as passerines head south towards warmer climes. Whinchats and Wheatears were reported locally in the first week, but no rarities were recorded. I was still busy photographing invertebrates, so relied on bird calls more than sightings during this period, although I did see at least three Spotted Flycatchers sallying forth from dead trees in Fox Covert to catch insects. Were these the family of birds that I saw in June and July or others passing through? I'll never know. Chiffchaffs were everywhere, sometimes appearing in parties of up to four individuals, but no Willow Warblers were heard or seen. A Raven was heard over Fox Covert on the 3rd, whilst a Green Woodpecker called nearby, the first time I've heard this species on The Heath for well over a year. A Bullfinch was heard near Royston Hospital on the 8th.
Blue butterflies became much harder to find in September, although several tatty Common Blues, a couple of Brown Arguses and a single male Chalkhill Blue were seen on the north side of Church Hill, mainly feeding on late-flowering Devil's-bit Scabious, on the 6th. No second generation Adonis Blues were seen at any time to the west of the Therfield Road: it seems very likely that this colony has, sadly, died out. Second generation Holly Blues have been few and far between this year. Perhaps the parasitic wasp (Listrodomus nycthemerus) that attacks their larvae had a successful season: these two species exist in equilibrium. The two butterflies that have done very well throughout the summer on The Heath, Meadow Brown and Small Heath, were still much in evidence: I must have seen about 50 of the former, many in good condition, on the 6th.
During September, my photographic interest turns towards grasshoppers, bush-crickets and spiders, all of which become far more evident as other insects disappear. I have only ever been able to find two species of grasshopper, Field Grasshopper and Meadow Grasshopper, on The Heath, whereas five species of Bush-cricket have been identified locally. This year Dark Bush-crickets and a single Roesel's Bush-cricket were the only ones seen on The Heath at the time of writing, although I am hopeful of finding more. Lots of Orb-web and female Wasp Spiders were seen, with Wasp Spiders particularly abundant at the bottom of Church Hill, where the specimens shown below were photographed.
Meadow Grasshopper, Church Hill, 3 September
