Yorkshire Status: Scarce and thinly distributed or restricted resident.
Sutton & Beaumont, 1989: Probably locally common on many of the moors in vice-counties 62-65. Occasional in other habitats in all five vice-counties.
2012 (CHF): Not uncommon in upland areas in May and June. It occasionally wanders to lower ground several miles away from suitable habitat. One at Spurn on 25.5.2010 could have been an immigrant as there are no populations anywhere nearby.
2020 (CHF): Is Glaucous Shears exclusively a moorland moth? Our Field Guide thinks so - "Habitat - moorland" it confidently states. Other literature agrees, though the Europeans take a slightly different tack, and Noctuidae Europaeae, tells us that throughout Europe it inhabits "humid, often swampy and marshy coniferous forests" with "massive" growth of bilberry. French literature also says bilberry is the food plant though our Field Guide plays down bilberry to a supporting role and says "bog-myrtle, meadowsweet, creeping willow, bilberry and heather".
So, if it's just a moorland moth, why do we get lowland records. There can only be three reasons.
a. Immigration. The Field Guide says "resident and suspected immigrant". I'm not quite sure what the evidence for immigration is. OK, it turned up at Spurn in 2010 and 2018 but if you look at the Atlas and go clockwise around the coast from Spurn, you get all the way to Devon before there is a dot on the map. The only inland post-2000 dot in the south-east half of England is in south Cambridgeshire. If it is a migrant, why are there no records on the coast? Where does it migrate from? European literature doesn't seem to mention its migrant status. The Atlas suggests it might be an immigrant on Orkney. Why just there? I would have thought that immigration was not a common reason for out-of-area records.
b. A tendency to wander. Some upland moths quite commonly seem to wander to lowland habitats. For example Haworth's Minor and Heath Rustic. In my own garden I have trapped Glaucous Shears on three occasions in 20 years, usually after westerly winds, and I am seven miles as the moth flies from suitable habitat. Other sites closer to the moors have trapped it a little more often. So, although it does wander, I am not convinced it wanders large distances. I would be surprised if it wandered 20 miles on a warm windy night.
c. It is not just simply a moorland moth and exists at a low density on (for example) our lowland heaths. Lowland heaths are not mentioned when it comes to describing the habitat of this species. It doesn't seem to utilise them in other parts of its range, for example it is absent from heaths in Dorset and Hampshire. There are however hints in some Yorkshire accounts. It was a common moth in Porritt's day and he listed a lot of sites, almost all in upland areas of the county, however one site on his list was Skipwith Common and we also know that Prest found it in 1883 at Askham Bog. In 1907 Porritt wrote that it "occurs more or less commonly on probably all extensive heaths and moorlands throughout the county". Sutton and Beaumont in 1989 said "probably locally common in many of the moors in vice-counties 62-65, but also states "occasional in other habitats in all five vice-counties". Since then, it has been seen at Skipwith rather vaguely "in the 1980s" and two records at Haxby in 2009 and 2019 raise the question as to whether these might be wanderers from an undiscovered population at Strensall Common which is a stone's throw away. 2020 was a very good year for Glaucous shears in Yorkshire with 59 records of 175 moths from 34 sites, mostly in the usual upland areas in the west of the county and the east of VC62. There were big numbers on Keighley Moor with several counts into double figures, so the habitat here must be ideal. Of more interest however were six unusual records from lowland sites, at Owston, Wintersett and Austerfield in VC63 and at Askham Bog, Bishopthorpe and Ripon in VC64. The Ripon moth might have been a wanderer, but some of the others are just too far for wandering moths to travel on westerly winds. The Askham Bog record this year is interesting, and there is plenty of bog myrtle at this site. Perhaps it is resident there. Bishopthorpe is only a mile or so away so perhaps this was a moth wandering from the same site. Was the Austerfield moth a wanderer from Hatfield Moors? Was the Owston moth a wanderer from Thorne Moors? Where did the Wintersett moth (the second at this site) come from? As usual, the more one studies the records that come in each year, the more questions need to be answered.
Retained Specimen / Photograph will be Required.
Recorded in 91 (46%) of 200 10k Squares. First Recorded in 1883. Last Recorded in 2022. Additional Stats