April's dry, warm and sunny weather continued until the night of the 3/4th, when the first significant rain since late March arrived. There followed a couple of cool days, then pleasant, warm weather from the 7th to the 9th. However, after this the weather turned much cooler and more changeable, with showery outbreaks of rain and temperatures that struggled to reach 10C on some days.
A trip to Amwell on the 3rd was rewarded with views of Reed, Sedge and Cetti's Warblers. A male Cuckoo gave me the run around as it moved round its territory, but I eventually got a distant view (image below). A couple of Swifts, seen over the house on the 5th, signalled their arrival back in Royston and a single House Martin was seen on the 12th over Hatchpen Farm, the only place on my local patch that I am aware of where this declining species still nests. Juvenile birds were represented by the local Rooks and families of Long-tailed Tits (both species nest early in the year).
Distant 'Record Shot' of a Cuckoo, Amwell NR, 3 May
The generally colder weather resulted in a decrease in insect sightings, although I did see my first Common Blue of the year near Phillup's Lake on the 10th. Small numbers of Brown Argus, Small Heath and Small Copper butterflies were seen in a variety of places on the warmer days. There was a modest influx of European Painted Lady butterflies into the country in late April, and one or two were seen on my local patch, alongside larger numbers of (the also migratory) Red Admiral. Orange Tips, Holly Blues and various 'Whites' were still on the wing in good numbers. Amongst the other insects seen during the first part of May were a couple of Wasp Beetles.
Wasp Beetle (a Longhorn Beetle), Therfield Heath, 9 May
Corn Buntings finally took the hint that it was time to start nesting, and three singing males were seen in fields within a mile of the house on the 12th. On another visit to Scales Park on the 13th I again failed to record any Crossbills (I only cover a relatively small section of the woodland on my visits, so I would not rule out the possibility of them breeding elsewhere in this area). Compensation came in the form of two newly fledged Ravens that were being fed by an adult. Ravens have nested here for years, but it was nice to confirm successful breeding. A few Speckled Wood and Small Heath butterflies were seen, despite the cold (12C), windy weather.
Corn Bunting, Royston, 12 May
Juvenile Raven, Scales Park, 13 May
On the evening of the 12th I helped my friend John check the owl boxes on his farm. Next to the first box we found a 'just about fledged' Tawny Owl (image). A parent was seen nearby. However, these were the last owls that I saw. Barn Owls are around on the farm: they nest much later than Tawnies, so there is a chance that they will still use one of John's boxes.
Baby Tawny Owl, Rushden, 12 May
The weather changed dramatically in the week from the 18th as, after a couple of unsettled days, high pressure and southerly winds saw temperatures rise from below normal to a record-breaking high of 35C (London) on the 25th. Back from three nights in Northumberland (separate blog post in due course) I visited Church Hill on the morning of the 23rd and was not surprised to see around ten male Adonis Blue butterflies (first generation) zooming around in the heat. Later in the day my partner and I walked across Lankester Hill, at the opposite end of The Heath, and I saw at least two male and two female Adonis Blue butterflies there, too. They had probably been on the wing for a couple of days. The Adonis Blues seemed to disperse over the next few days as temperatures rose still further - photographing them in the heat proved challenging! A visit to Hillbrow (Letchworth) on the 26th was rewarded with views of several Small Blues (image below).
Male Adonis Blue, Church Hill, 23 May
Small Blue, Hillbrow (Letchworth), 26 May
Both Small Blues and Adonis Blues had been reported at Clothall Common (off the A505 between Baldock and Royston) in previous years. Since both species were on the wing, I decided to visit on the 27th to see whether I could detect either. Male Common and Adonis Blues are hard to separate in flight, but all the butterflies that I was able to identify on the ground were Common Blues. However, after much searching I did manage to find a couple of Small Blues - the first that I have seen at this site. There is plenty of Kidney Vetch (their food plant) on Therfield Heath, but I have never detected Small Blues there. Maybe this year?
The extreme heat of late May, both here and in continental Europe, was the likely cause of a major influx of Painted Lady butterflies into the country towards the end of May. I counted around 30 at Clothall Common on the 27th and up to two were feeding in the garden over the last few days of May, with Valerian being the favoured source of nectar. I remember the Painted Lady 'invasion' of 2009: this was perhaps the biggest influx since that year.
Painted Lady on Oxeye Daisy, Clothall Common, 27 May
Two Tawny Owlets were calling from different parts of a local wood, indicating that they had fledged, when I did my first dusk 'owl walk' on the evening of the 28th. I still don't know where the nest site is, but they often appear in this woodland and I hope to be able to see and possibly photograph them in June. A very active Badger Sett was nearby - Badgers are common in the Royston area, but I rarely see them. Here, at least four were snuffling about in the vegetation and one came right up to me. My search for Spotted Flycatchers on The Heath had been less successful - visits to the woodland on either side of the Therfield Road, where they usually appear, drew a blank in the second half of May. However, I did find at least one bird in woodland not far from the golf driving range when I walked east to west across The Heath on the 29th. The thought that this scarce and declining species had abandoned The Heath would have been too much to bear! Also seen on the same walk were a couple of Meadow Brown butterflies (my first of the year) and a female Large Red Damselfly, not far from the house (images to follow).
