Local Wildlife Sightings July 2024

 Despite a cold first half of June, we did see a brief sign of summer in the second half of the month. Sadly, it wasn't to last. July started cool and unsettled, and things got steadily worse during the first week, culminating in around 15 hours of more or less continuous rain from the 5th into the 6th, which added 30mm (1.2 inches) to the garden rain gauge. In what should be my busiest period for wildlife photography I was only able to get out for an afternoon and evening on the 2nd and likewise on the 4th, when windy weather made insect photography very challenging indeed. Rainfall amounts continued to mount during the rest of the month, but there were also spells of drier, warmer weather and a second mini heatwave between the 17th and the 19th, with the temperature reaching 31C on the 19th.

Despite the poor weather, the early part of July did provide some wildlife highlights and, surprisingly, these came in the form of birds. I visited Scales Park woodland (between Nuthampstead and Meesden) on the 2nd, looking mainly for insects and perhaps a better view of the Marsh Tit family that was seen here in June. As part of my walk I do a 'there and back' from one end of the main ride to the other. On the outward leg the woodland was very quiet, with a Southern Hawker dragonfly (which caught and ate a Meadow Brown butterfly, tearing off the wings as it munched) the only sighting of note. However, on the way back I paused to see and hear a large, loose flock of birds (including several tits, Nuthatch, Treecreeper and Goldcrest) on both sides of the ride. Whilst looking at some birds moving through the tree canopy I noticed the back of a small bird that was resting lengthways on a small, high branch. I couldn't see its head at first, but the markings on the back were consistent with my first Hertfordshire Lesser Spotted Woodpecker! Eventually I managed to move round to a point where I could see the bird's head and was pleased to confirm my sighting. I couldn't see any red on the crown, so I assume that this was a female, which had been probing the bark for invertebrates. Great Spotted Woodpeckers are common in the mixed woodland - indeed, I heard some on this visit. I wonder whether Lesser Spotted Woodpeckers breed here (much of Scales Park is 'off-limits'), or perhaps this bird was just passing through (*see comments). No photos, I'm afraid - the bird flew away whilst the camera was still in the bag.

Southern Hawker Dragonfly, Scales Park, 2 July

I have been monitoring the activity of the Spotted Flycatchers on The Heath since late May. Activity had been becoming quite frenetic, and I was confident that the adults were feeding young. I was delighted to record at least two fledged juveniles, being fed by their parents, in Fox Covert on the 4th. I'll leave them in peace now! On the 6th I made probably a final dusk visit to the Tawny Owl and Little Owl territories close to my house. There was no sign of the Tawny juveniles, but I did catch a glimpse of a Little Owl flying away near its nest site (on private land). I wonder whether this is the only remaining bird in the area: there has been no sign of breeding activity this year. Little Owls are declining fast in the UK, for reasons that are not fully understood, but I expect that our activities are the main cause. I had a better sighting of a Little Owl in the same place on the 16th, this time in the late afternoon. I'll continue to monitor the site (from the public right of way!) in case they are/were still nesting. A visit to Phillup's Lake (Reed End) on the 2nd produced large numbers of moulting Mallards, 12 Coot (eight young), a pair of Canada Geese, three Tufted Ducks and at least one Little Grebe although the last was, as usual, only heard. Two new species of Odonata for the site, Broad-bodied Chaser and Azure Damselfly (a female) were seen here, but there was little dragonfly activity on a cool day.

Juvenile Coot, Reed End, 2 July

I added two new butterfly species (Essex Skipper and Gatekeeper) to my year list on the 1st, both on Therfield Heath. Decent numbers of species whose caterpillars feed on grasses were seen when the sun occasionally came out, with Ringlets actually being more common than usual, but numbers of many species were low and there was no sign of Chalkhill Blues, which normally appear in the first week of July. I had to concentrate my photography on Marbled White butterflies, which were plentiful and are, thankfully, very photogenic. I did manage to photograph a few other insects, mainly on Therfield Heath. A couple of my images are below.

Ichneumon Wasp (Species n/k), Therfield Heath, 4 July

Marbled White Butterfly on Ox-eye Daisy, Therfield Heath, 2 July

Chalkhill Blues (seven) were finally seen on The Heath (Old Rifle Range) on the morning of the 8th and numbers steadily increased during the rest of the month across The Heath to the east of the Therfield Road. Given the poor showings of the other blues, it was no surprise to find numbers further down on last year's somewhat below average numbers. Very worryingly, however, I could find none at all on Church Hill in July. This follows on from very low numbers found here in 2023. What has happened here? I speculated about this last year. Have the ant colonies upon which the caterpillars rely been wiped out? Were the record temperatures seen in July 2022 in some way to blame, since the south side of Church Hill is more exposed to the sun than anywhere else on The Heath? Has this slightly isolated colony been affected by some kind of disease? Is there not enough of their food plant, Horseshoe Vetch? Is the grass here too high? It will be interesting to see whether second generations of Common and Adonis Blues, both present here in very small numbers in the spring, emerge here in August. It may be necessary to monitor and compare the remaining population of Chalkhill Blues on Therfield Heath to those on other sites in the South East, to see whether similar events are happening elsewhere.

Male Chalkhill Blue, Therfield Heath (Old Rifle Range), 8 July

A single male Chalkhill Blue was seen at Clothall Common, near Baldock, on the 19th, where a small colony occurs. Several six-spot Burnet Moths, including mating pairs, were seen here but for me the most surprising sighting was of a very tatty, presumably first generation, Common Blue butterfly at a time when the second generation should have been (but aren't) starting to emerge. A few Dark Green Fritillaries were still around on The Heath in the second half of the month, but this has been a poor year for fritillaries locally, with no Silver-washed Fritillaries being seen by me either on The Heath (Fox Covert and Jubilee Wood) or at Scales Park. Having only recently established themselves in small numbers on The Heath, the loss of Silver-washed Fritillaries would be no great surprise and, given a few decent springs and summers (a big ask, it seems!), they will hopefully return.

Mating Dark Green Fritillaries, Therfield Heath, 8 July

However, this extremely dull, wet year has not been doom and gloom for all butterfly species. Those whose food plants are grasses have all had average to good years, with Ringlets, Gatekeepers and all three skipper species doing well. Indeed, at the time of writing this update (23 July), Essex Skippers seem to be everywhere and in big numbers. By late July new generations of Peacock, Red Admiral, Brimstone, Comma and the three common species of whites were all on the wing and I saw at least five pristine Painted Lady butterflies on my visit to Clothall Common on the 19th. Missing from this list, however, is Small Tortoiseshell, which is having another very bad year.

Mating Six-spot Burnet Moths, Clothall Common, 19 July

Essex Skipper, Royston, 18 July

Ruddy Darter, Banded Demoiselle and Broad-bodied Chaser Dragonflies were seen on or near The Heath during the month, and Southern Hawker dragonflies became more common and widespread towards the end of the month. Small Red-eyed Damselflies were seen on the lake during a visit with my partner to the Henry Moore Foundation at Perry Green, near Bishops Stortford, on the 21st. I also found (or, more likely, re-identified) another species of Shieldbug (Red-legged Shieldbug) near my house on the 19th. This individual took a bit of identifying, because it didn't have red legs and didn't look like the specimen illustrated in my go-to insects book ('Brock')! However, Brock does say that this widespread and common species does have variable markings......

Broad-bodied Chaser Dragonfly, Therfield Heath (Church Hill), 10 July

Red-legged Shieldbug, Royston, 19 July

Summer finally arrived in earnest towards the end of the month, with a heatwave extending into August. However, I was away in Scotland enjoying similar weather (cool, wet and windy) to what we had here in June (see the separate blog post).