Wednesday 7 April 2021

Local Wildlife Sightings April 2021

 The local daytime temperature dropped from 23C on the 31st of March to 12C on the 1st of April, prefacing a prolonged period of cold weather from the 5th which lasted throughout the month and into May, often with single figure daytime temperatures and overnight frosts so severe that they caused my garden ponds to freeze over on a couple of occasions at the start of the month (all the frogspawn left in the main pond died). Bird migration slowed dramatically, although I did manage to find my first yellow wagtail of the year just north of Ashwell, on the Eyeworth Road, on the 3rd. Reed buntings seem to be faring quite badly in my region, with none seen within two miles of my house since 2019, and a male bird seen alongside the yellow wagtail was my first in Hertfordshire for the year, despite visits to the reedbeds of Amwell and Tyttenhanger. Golden plovers stayed in the Royston area until well into April, with flocks of about 120 flying around over Greys Farm and Park Farm on the 6th, 90 (now largely summer-plumaged) birds at Greys Farm on the 13th and up to 20 birds still at Greys Farm on the 19th.  For the first time I failed to record a willow warbler on my local patch (within two miles of my house) in April, although birds were seen in the villages of Reed and Therfield (see below). Only two swallows (at Hatchpen Farm on the 17th) were seen during the month and I recorded no house martins, swifts or lesser whitethroats locally either.


Goldcrest, Therfield Heath, 20 April

Finding passage migrants on my 'local patch' also proved to be a struggle for me this year. I did eventually see three wheatears in a well-watched ploughed field at Greys Farm, just off The Heath, on the 8th. Up to eight were reported there in the following days, although when I looked on the 12th I again could only see three (two males and a female), with two present on both the 19th and the 26th. I have found ring ouzels on my local patch for the last six years, but there was no sign of any this April, although Andy Symes found an elusive individual off Coombe Road (Kelshall) on the 12th. I decided to visit Weston (near Baldock), where I caught up with a well-watched individual, as well as a young male redstart, on the 8th.


Two Male Wheatears, Greys Farm, 8 April


Male Ring Ouzel, Weston, 8 April

I recorded common snipe, white wagtails and a pair of shelduck, as well as lots of little ringed plovers, on two further visits to Stanborough gravel pit. After a couple of weeks' absence two flocks of Fieldfares (25 + 58) were seen during a walk to Hatchpen Farm on the 7th. My guess is that these were stopping off on migration from further south, rather than local wintering birds. 
I recorded 48 bird species (44 seen) on a long walk through the villages on the 12th. The wintering mute swan had finally left Mardleybury Lake, but a little grebe was seen - my first local sighting of the year for this species, which has bred or attempted to breed here for each of the last three summers. Nothing new was seen on the walk, with a flock of 115 fieldfares in Therfield, displaying lapwings in two places and a single raven over Greys Farm being minor highlights. Whitethroats arrived back in the final week of April, with five recorded on a walk part way up the Icknield Way from Royston Hospital, but by the end of the month I had only recorded these and two other warbler species (chiffchaff and blackcap) locally. However, on the final day of the month I did hear a nightingale singing intermittently at Wisbridge Farm (Reed), my first since the 'Tesco filling station' bird.

Willowchaffs
When people talk about 'willowchaffs' they are usually referring to a sighting of one of the two small, brown phylloscopus warblers willow warbler and chiffchaff, which are hard to separate in the field when they are not singing. However, I have come up with a different definition - a willow warbler that incorporates chiffchaff phrases into its song. I first came across one of these birds in Reed village in 2020 and sound recorded it. This April I came across two more birds, one at Oughtonhead (Hitchin) and the other south of Therfield village, which did the same thing. Their willow warbler song is very clear and unmistakeable, whilst the chiffchaff phrases are, in varying degrees, more hesitant. My explanation of this strange behaviour is that, as breeding chiffchaffs are becoming more common in the Hertfordshire area whilst breeding willow warblers are becoming increasingly rare, the young local willow warblers in the nest are picking up both the songs of their fathers and of the surrounding singing chiffchaffs. I am not the only person to have recorded this phenomenon. Other explanations would be welcomed!


'Willowchaff', Therfield, 22 April


Insects
Insects were thin on the ground in the cold weather, but I did enjoy the antics of the hairy-footed flower bees at Hatchpen Farm, where they nest in a bank. The males buzz around outside the holes that the bees make in the bank, whilst the females fly directly into the holes with (presumably) pollen. These bees are only on the wing between March and May, so they disappear at least three months before ivy bees (which also dig holes) emerge in the early autumn!


Female Hairy-footed Flower Bee, Hatchpen Farm, 12 April


Male Hairy-footed Flower Bee, Hatchpen Farm, 29 March


I saw and photographed a few common species of hoverfly (Eupeodes luniger, Syrphus ribesii, Eristalis pertinax and an unidentified, tiny fly which annoyingly always perches with its wings closed over its abdomen) in the garden and the local woodland. Perhaps more interestingly, I noticed several individuals of what I believe is a nomad bee (possibly Gooden's nomad bee) in the local wood. The females of this species parasitise other bees (Andrena spp.). I did find a possible Andrena individual nearby, but was unable to identify it.


(Gooden's?) Nomad Bee, Green Walk Plantation, Royston

I only saw five species of butterfly on my local patch in the whole of April - a very disappointing total, but hardly surprising given the cold conditions. The temperature barely rose above 15C, and then only for a few hours during the middle of the day when the sun was out. Orange tips and green-veined whites joined the over-wintering brimstones, peacocks and small tortoiseshells on the wing, with at least 30 green-veined whites and ten male orange tips active along the Icknield Way on the 30th. Things can only improve in May - can't they?

Other Flora and Fauna
Pasque flowers put on a good display again on Church Hill, despite the very dry and cold weather, as did cowslips on various parts of The Heath and bluebells in the woodland along the ridge between Barkway and Sandon. Hares were very active, with eight being seen in the ploughed field at Greys Farm on the 19th.




UK Wildlife Sightings April 2021

 Following the mini-heatwave at the end of March came the long freeze in April. Daytime temperatures dropped by about 12C between 31 March and 1 April and, by the 5th, were in single figures with overnight frosts and strong northerly winds. Bird migration predictably dropped, with birds stuck in Continental Europe waiting for the opportunity to fly further north. Wood anemones were noticeable as I did a couple of Easter walks with my partner in South Hertfordshire, making me wonder where the nearest woodland was to Royston that harbours this species - I haven't seen it on any of my local walks.


Wood Anemones and Lesser Celandine, near Little Berkhamsted, Herts. 5 April

On the 9th I visited Breckland, achieving my main objective of seeing lesser spotted woodpecker at a well-watched site near Santon Downham. Hundreds of crossbills and lesser redpolls (the latter a year tick because of the pandemic lockdown) were very noticeable and, at one point, some crossbills came down into a willow tree close to the path - allowing very good views. Unfortunately it wasn't possible to isolate the birds for photography without twigs and branches getting in the way: my best effort is shown below.


Male Crossbill, Santon Downham, 9 April

My partner loves walking by the coast, so on the 11th I took her to Thornham, from where we walked along the coastal path to Holme and back. Thornham Harbour is an excellent venue for wader photography and I was able, without any trouble, to get decent images of six of the twelve wader species that we saw. The composite image below shows these six species: I will leave it to the reader to identify the waders!


Images of six wader species photographed at Thornham Harbour on 11 April

My first long trip of the year came on the 14th, when I visited my county of birth to enjoy watching and photographing the seabird colonies between Flamborough Head (North Landing) and RSPB Bempton Cliffs. The weather was cold (of course) but sunny. As expected, thousands of gannets were starting to nest (gannets start to return to Bempton from late January onwards!). Perhaps more unexpectedly, hundreds of puffins had already returned. However, the biggest surprise was to see huge numbers of razorbills on the cliffs and in the water - they far outnumbered guillemots, both on land and on the sea. There had been a report of 88,000 razorbills passing Flamborough Head in a single day a few days beforehand: from the numbers seen I reckon a good proportion of those birds had stayed in the area! Migrant land birds were thin on the ground in unfavourable conditions, no short-eared owls were seen (although they were reported before and after on the day of my visit) but tree sparrows made, as ever, obliging photographic subjects.


Gannet in flight at RSPB Bempton Cliffs, 14 April


Razorbill Dance! Flamborough Head, 14 April




Puffin, North Landing (Flamborough Head), 14 April

More local bird watching produced some dividends, particularly on the 21st when, encouraged by reports of a big passage of Arctic terns, I visited the Tring reservoirs. Waders at Tringford (where the water levels were low, resulting in plenty of exposed mud) included at least five little ringed plovers and a pair of redshanks. I saw my first reed warbler of the year at Marsworth. Two male mandarin ducks here in perfect breeding plumage provided an irresistible attraction for my camera, but most of the action was at Startops End, where I eventually located a handful of Arctic terns amongst large numbers of common terns. Although distant, the longer tail streamers, short blood-red bills and neat dark lines along the trailing edges of the undersides of the wings enabled me to separate out the Arctic terns. Just as I had convinced myself that I was seeing Arctic terns an adult (or near adult) little gull appeared, typically feeding in flight, tern-like, on the surface of the water, to complete a satisfying visit.


'Record Shot' of Arctic Tern, Startops End Reservoir, 21 April


Common Tern, Marsworth Reservoir, 21 April


Adult Little Gull, Startops End Reservoir, 21 April


Male Mandarin Duck, Marsworth Reservoir, 21 April

On the 23rd I visited the Holkham Estate as a 'Naturetrek' client on a one day £50 wildlife trip (see the October 2020 blog for my first taste of one of these trips), with Mike Crewe as the leader. Between us we recorded almost 90 bird species, including my first whimbrels and spoonbills of the year, and Mike educated us on the five different varieties of pine trees that occur in the area.

With the news that 'Colin the Cuckoo' was back at Thursley Common (Surrey) for an 8th successive spring I decided that another photographic visit would be in order on the 27th (one of the few remotely warm days of this ridiculously cold spring). Colin made a couple of brief visits to the feeding station in the Parish Field during the 75 minutes that I was there. Although I failed to get the variety of photos of Colin that I had hoped for, several other interesting birds posed for me at the feeding station including redstart, woodlark and a very obliging mistle thrush. Elsewhere, I noted several Dartford warblers and a couple of hobbies. Little buntings were still being reported at 'Bunting Bushes', but a brief visit there failed to reveal any and I didn't see or hear any tree pipits - possibly they had yet to arrive from Africa.


'Colin the Cuckoo', Thursley Common, 27 April


Mistle Thrush, Thursley Common, 27 April





Male Common Redstart, Thursley Common, 27 April


Woodlark, Thursley Common, 27 April

The following day I visited Broom Gravel Pits (near Biggleswade, Beds.) on a reconnaissance trip for a future RSPB visit. Greenshank, dunlin and common sandpiper (not seen by me) were present, as were more Arctic terns (I suspect that their excellent passage through our region has been boosted by the prevailing easterly and north-easterly winds pushing them further west than usual). I also saw my first swifts and house martins of the year here, boosting my year list to a respectable (considering the circumstances) 174 species by the end of the month.