Royston Wildlife Blog: Local Wildlife Sightings May 2021

The cold, dry conditions of April continued into May, only to be replaced on the 3rd when a storm blew in from the Atlantic, giving us cold, wet conditions instead! There followed a few more cold days before the wind changed to a westerly, bringing in regular low pressure systems, cool weather and lots of rain. This was more like the springs of old, when I was growing up in Yorkshire! Although the weather was depressing, the rain did at least cause vegetation to grow rapidly, providing a lush carpet of wild flowers and grasses which might, if the weather ever warmed up, provide plenty of insect life - eventually.

I recorded my first local yellow wagtail of the year at Hatchpen Farm on the 1st and, just before the storm arrived on the 3rd, I finally saw willow warblers on The Heath - one at either end. Wheatears stayed around at Greys Farm until at least the 6th, the first lesser whitethroats appeared (two weeks late) from the 5th (in Reed), with three recorded along the Icknield Way on the 7th. After much searching I managed to track down a marsh tit in Rokey Wood (Reed) on the 5th - I fear that this is a species that is just hanging on in my area and may well become locally extinct soon. A swift was seen in Royston on the 8th, but there was no obvious sign of a general arrival - presumably the birds were waiting for better weather before they start nesting.

Corn Bunting in a Field of Rape, Hatchpen Farm, 5 May

Although bird watching was a pretty depressing affair, there were occasional highlights. On the 11th I encountered not one but two reed warblers on a walk up the Icknield Way. Although reedbeds are pretty scarce in the Royston area it is not unusual to see reed (and sedge) warblers here on passage, but I've never come across two here on the same day! The following day I saw my first local house martin of the year at Hatchpen Farm. After a few years' absence, rape is being grown again in my area and I noted what has recently become a local rarity (a reed bunting!) in a field of rape, alongside its much more common cousins - corn buntings (see image above). There was no sign of garden warblers locally this year (although my coverage of the area was patchy, so birds may have gone unnoticed). However, spotted flycatchers did return to their familiar haunts in good numbers with five being recorded in woodland either side of the Therfield Road on the 15th and at least four still present on the 17th. It has been too cold to have the house windows open this spring, but the night of the 9-10th was warmer and I heard a tawny owl hooting nearby in the early hours.

Spotted Flycatcher in Fox Covert, 17 May

Other Wildlife

The mining bees at Hatchpen Farm continued to interest me. I struggle to identify bees, other than bumble bees, but it became clear that I was dealing with more than one species of mining bee here. I couldn't find any hairy-footed flower bees (see previous posts) when I looked on the 5th, but at least two other types (possibly male and female of the same species) could be seen, along with some nomad bees, again tentatively identified as Gooden's nomad bee. This bee is known to parasitize at least five other species of Andrena mining bees, but I couldn't identify which, if any, of these species were also present. The image below shows the larger of the two 'types' of mining bee that I saw.

Gooden's Nomad Bee, Hatchpen Farm, 5 May

Unidentified Mining Bee, Hatchpen Farm, 5 May

The only butterflies that I saw on the wing in the first half of May were thinly-scattered orange tip, green-veined and small white, peacock and brimstone. Trying to photograph these for my continuing ARPS project proved to be an extremely frustrating and fruitless task! At last, on the 17th, a visit to Church Hill provided me with my first local 'blues' of the year in the shape of three brown argus butterflies. I also saw a red admiral nearby and, a few hours later, I added a single holly blue to my 'seen locally' butterfly list. The brown argus butterflies appeared 15 days later than they did last year. However, with the appearance of rock rose, kidney and horseshoe vetches in the middle of the month, my hopes were raised that other blues might make an appearance in the next couple of weeks - despite the never-ending cool, wet and sometimes windy weather!

Female Brown Argus Butterfly, Church Hill, 17 May

Female Brown Argus Butterfly (a different one), Church Hill, 17 May

Other insect life in mid-May included a big hatch of St Mark's flies on The Heath, a cinnabar moth and a couple of large, unidentified moths that didn't give me a chance to photograph them. White helleborines were emerging slowly from the ground and both red and white campion started to flower.

Male Orange Tip Butterfly, Royston, 8 May

Three St. Mark's Flies, Therfield Heath, 11 May

Finally, after eight weeks of continuously below average temperatures and four weeks of rain, the weather gods finally relented in the last few days of the month and sunshine and temperatures in the 'low twenties' arrived. I was quick to spend time on The Heath looking for butterflies and other insect life and was rewarded when, on Church Hill on the 27th, I found a female Adonis blue. At least five Adonis blues (including a mating pair) were present there the next day and, by the end of the month, 35-40 males were on the wing here, although I was unable to find any elsewhere on The Heath. The fact that this butterfly species had survived the wretched winter and spring gives me confidence that this very attractive addition to our fauna is here to stay. The Adonis blue relies on ants for protection during the caterpillar and pupa stages of its life cycle, and I photographed one emergent male with a black ant apparently attached to its rear end! Increasing numbers of common blue, brown argus and small heath butterflies were also appearing by the end of the month.