Royston Wildlife Blog: Local Wildlife Sightings, July 2026

Early in July, we received the very sad news that a developers' appeal had successfully overturned the council blocking of a 280 home development on fields adjoining my estate. Along with the inevitable major traffic disruption that the building work will entail and the further dilution of local services, this will mean the loss of a lovely wild flower meadow near the house - very bad news indeed, and another kick in the teeth for conservation and green field sites.

Back from holiday, I visited Therfield Heath (east side) on the morning of the 5th. Initially everything was quiet, but as soon as the sun came out clouds of butterflies emerged from the grasses. Foremost amongst them were Chalkhill Blues - I reckon that I must have seen at least 200. I also saw my first Gatekeeper butterflies of the year: these tend to congregate around the bushes on The Heath. A few Dark Green Fritillaries were still flying and I actually managed to get a few photographs of one - quite a challenge, as this fast flying butterfly never seems to stay still for more than a couple of seconds.

Male Chalkhill Blue, Therfield Heath, 5 July

Male Chalkhill Blue Variant (Smaller or Incomplete Spots, c.f. the Butterfly above), Therfield Heath, 5 July

Gatekeeper Butterfly, Therfield Heath, 5 July

Dark Green Fritillary, Therfield Heath, 5 July

Closer to home, a new (for my local patch) micro-moth, Pyrausta purpuralis, was recorded.

Pyrausta Purpuralis, Royston, 5 July

The hot, dry summer continued with another heatwave, starting around the 5th and lasting for at least 10 days with temperatures reaching 34C (so not as hot as in June!). After that the weather cooled somewhat, with an easterly wind bringing in early morning cloud, but not a drop of rain was to be had until the morning of the 26th, when 2.5mm fell - hooray! After that it was back to heatwave conditions, with the temperature reaching 34C on the 29th. July became the second hottest month ever in England and also one of the driest. Plants withered and crops were harvested early. By the middle of the month thousands of Chalkhill Blues had spread all over The Heath and a few males were seen a mile or two away from the nearest colony, although they would have been frustrated at being unable to find any of the far more sedentary females. I spent a lot of time in the evenings photographing roosting 'blues' (second generation Common Blue and Brown Argus butterflies were on the wing from the middle of the month), because they were too active in the hot, daytime temperatures. However, the females emerge from their chrysalises in the morning and immediately mate with whichever passing male is lucky enough to find them. I was therefore lucky to find a mating pair on a rare morning visit to The Heath (just east of the Therfield Road) on the 11th (image below). On a later morning visit to the Old Rifle Range (24th) I counted eight mating pairs in quite a small area.

Mating Chalkhill Blue Butterflies, Therfield Heath, 11 July

Following the emergence of Chalkhill Blues and Gatekeepers, I had only one 'regular' butterfly species left to see on The Heath - Silver-washed Fritillary. This butterfly was seen for the first time in the Fox Covert / Jubilee Wood area six or seven years ago and has since colonised this woodland, albeit in very small numbers. I now know their favourite areas, and saw my first butterfly on the 9th. I returned on the 11th, when I saw at least three, including both a male and a female, and on the 14th when, perhaps getting tired of being pursued by me, I was able to photograph two different males and a female, whilst a fourth butterfly (another male) was seen. Hopefully more females were around, and this colony will (continue to?) grow. Silver-washed Fritillary was the 28th butterfly species to be seen this year on my Local Patch and six days later the 29th, a Clouded Yellow, was seen on The Heath (Old Rifle Range). This was no big surprise, as several were reported elsewhere in Hertfordshire in July. Of the 29, only Clouded Yellow and Painted Lady are not resident, although in good summers the latter goes through a full breeding cycle here, but neither species can survive our winters - yet! There were no further sightings of Silver-washed Fritillaries on subsequent visits to The Heath, although another Clouded Yellow was seen on Church Hill on the 27th.

Female Silver-washed Fritillary, Therfield Heath, 14 July

Male Silver-washed Fritillary, Therfield Heath, 14 July

Silver-washed Fritillaries were also seen on two visits to Scales Park in the first half of the month, whilst three second generation Small Blues were seen when I visited Clothall Common (Baldock) on the 15th. The colony of Chalkhill Blues at Clothall must have numbered well over 100.

Small Blue, Clothall Common, 15 July

Local dragonflies were rather thin on the ground. It was surprising not to see Common Darters by the middle of July: have all the local ponds dried up? I visited Panshanger Park (between Hertford and Welwyn Garden City) on the 17th, hoping to see a reported Southern Migrant Hawker (still a rare dragonfly, although expanding in numbers and area - another beneficiary of climate change). I missed this, although there were plenty of the commoner dragonflies about, with Black-tailed Skimmer being the commonest. I saw lots of Ruddy Darters there, but no Common Darters. As the month wore on, Migrant Hawkers (first seen on the 14th) started to appear locally. This smallish hawker dragonfly tends to become very common here in August.

Black-tailed Skimmer, Panshanger Park, 17 July

Record Shot of a Migrant Hawker, Therfield Heath, 14 July

Hereabouts, bird activity dies back to practically nothing in July, as nesting finishes for most and I take a break from the delights of failed gull identification (there aren't any gulls to identify). However, after a Herts. Bird Club report (Paula Moore) of Spotted Flycatchers in Fox Covert on the 13th I realised that I had been neglecting this species. An investigation on the 14th revealed at least five birds in two areas of the woodland that were separated by a few hundred metres. One adult bird was feeding at the edge of woodland. I managed to photograph it (after putting my arm on to barbed wire and losing a fair bit of blood) and noted it feeding a juvenile at one point. Whether the birds were from one family or from two separate ones, it was good to know that they have successfully bred again in the woods. Other bird sightings of interest were of a family of seven Grey Partridges (two adults and five tiny chicks which were, nevertheless, able to fly for cover when they saw me approaching) on the Old Rifle Range on the 24th and a family of at least five Chiffchaffs with recently fledged young, near Royston Hospital on the 27th.

Adult Spotted Flycatcher, Therfield Heath, 14 July

'Record Shot' of an Adult Grey Partridge (one of a family of seven), Therfield Heath, 24 July

The path that loops round Phillup's Lake from the road between Therfield village and the A10 had become impassable, being blocked by brambles, nettles, thistles and various other stinging and cutting plants. I don't know who is responsible for maintaining it, but they are not doing a very good job! I decided to cut a swathe through this jungle on the 14th. It took 25 minutes and I ended up covered in cuts and scratches (I was wearing shorts). My reward was to see at least six Little Grebes on the lake - at least three adults and three tiny young - suggestive of two pairs having bred on the lake. It is so difficult to count the grebes, because as soon as they sense my presence they dive under the water and head for cover at the side of the lake. However, the baby grebes apparently can't dive at an early stage and don't swim very fast, which makes it easier to count them!

I finally saw my first local Common Darter in Fox Covert on the 27th. Its photo is below, together with a few other images taken locally during an intense period of butterfly photography.

Female Common Darter, Therfield Heath, 27 July

Female Common Blue, 'mariscolore' Variant, Therfield Heath, 24 July

Roosting Chalkhill (Upper Butterfly) and Common Blues, Therfield Heath, 20 July

Painted Lady Wing Detail, Royston, 27 July

On my way to a garden centre I popped in to Dernford Farm Reservoir (Stapleford, Cambs.) on the 30th to look for birds and dragonflies. It was no surprise to see that the lake had almost dried up. A single Redshank was probing the mud here and a group of Lapwings were present, but no other waders could be seen. However, a pale yellow dragonfly on the perimeter path caught my eye and turned out to be a Red-veined Darter. This dragonfly is another continental immigrant, which is becoming more common as a result of climate change. However, numbers vary greatly from year to year. The species is unusual in that if adults mate and drop eggs in the spring, dragonflies can emerge in the same year. Also seen here were several other species, including a mating pair of Common Blue Damselflies, where the head of the female is, unusually, coloured yellow.