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
Female Wasp Spider, Church Hill, 3 September
Female Wasp Spider on her Web, Church Hill, 6 September
During September I went on two long 'round the villages walks, on the 11th and the 25th, either side of a week's holiday with my partner (14-21st). These walks are largely aimed at improving my fitness (I'm still putting on weight), but of course I am always on the lookout for birds and invertebrates. Co-incidentally, I saw 38 bird species on each walk. The star bird on the first walk was Willow Warbler (two sightings, ID by call), my first local sightings of the year of a species that used to breed in good numbers in the Royston area but is now only seen as an occasional passage migrant. At least two Ravens were flushed from a dead tree at Reed End (Therfield) and five species of water bird, including two Little Grebes, were seen at Phillup's Lake. On the second walk I saw no fewer than five Ravens in the same dead tree at Reed End: is this a family group or a place for Ravens to socialise? Two Ravens, presumably different birds, were seen earlier heading north as I was walking up the Icknield Way. A single Wheatear was seen near the 'Raven Tree'. Five Tufted Ducks (four females) were on Phillup's Lake, but there was no sign of Little Grebes on this occasion. My biggest shock came on the way back through Newsells Stud Farm, when I saw my first local Green Woodpecker for two years! I have heard them 'yaffling' on many occasions this year (more so than in 2023), but they had always been 'in the next field' or 'just over the hill' - the latter a bit like me, I guess.
Gulls Following the Plough, Therfield, 11 September
Five Ravens in a Dead Tree, Reed End, 25 September
Tufted Ducks at Phillup's Lake, Reed End, 25 September
Lovely weather on the 13th prompted me to look at both ends of The Heath for invertebrates. Large numbers of Ivy Bees were taking nectar from Ivy flowers, both off and on The Heath, being joined from time to time by other bumble bees, Honey Bees, hoverflies and Red Admiral butterflies. A few rather jaded Common Blue butterflies were seen at both ends of The Heath and it was reassuring to see, in addition to 6-8 male Adonis Blues on Lankester Hill, a single female. Migrant Hawker and Common Darter dragonflies were still on the wing. These were all in an area where the vegetation had been machine-cut last year whilst this year a swathe of vegetation lower down the hill has been cut. Vegetation on both sides of Church Hill was cut later in September. This will hopefully do the job that Rabbits are supposed to do (but there are too few to do it) and sheep are now not allowed to do (apparently due to dog attacks), encouraging the growth of wild flowers and the vegetation that supports Therfield Heath's special invertebrates. This was, apparently, a very expensive job, but well done to all concerned for doing it.
Common Darter, Therfield Heath, 13 September
Ivy Bee on Ivy Plant, Royston, 13 September
Red Admiral Nectaring on Ivy, Royston, 13 September
This proved to be probably my last productive visit of the year to The Heath to photograph invertebrates. Having arrived back from holiday on the 21st (and found a Speckled Bush-cricket and a Hawthorn Shield Bug in the garden), the following week produced dull weather with frequent rain. On the few occasions when the sun shone, the only butterflies seen were the 'cabbage whites' and a few Red Admirals and Meadow Browns. Migrant Hawker dragonflies were still active and I saw a few Dock Bugs (on Dock leaves, of course) and grasshoppers. Craneflies were very common and a few hoverflies were still buzzing around, but it looks like the end of September will be the time to put my macro lens away for another year.
