Holly Blue, Rutland

Holly Blue, Rutland

There was a distinctly autumnal feel in the air today. Some of our summer butterflies are coming to the end of their season, and numbers generally seem low.

Two species which are having a good year are Holly Blue (still) and Brown Argus. To date I have seen more second brood individuals of the latter than Common Blue, which is unusual.

Brown Argus, Rutland

Brown Argus, Rutland

Double-crested Cormorant: the rarer the bird, the more significant each record

Double-crested Cormorant: the rarer the bird, the more significant each record

There has been some misinformed discussion about records committees on birding discussion groups recently, so this seems a good time to set out my experiences of the committees for which I have served: many years on a county records committee (L&R), many years on a national records committee (BOURC) including a term as secretary, and attendance at a European (AERC) records committee meeting in 2009.

Without exception, these committees have worked hard and done a good job. Perfection is of course an unattainable target – committees are groups of people who by nature sometimes make mistakes – but the vast majority of their decisions stand the test of time.

Europe At a formal level the AERC has not been entirely successful, partly because of its nature and the logistical problems associated with such a large and varied body. At an informal level it has been very successful. For example, conversations I had at the 2009 meeting contributed to subsequent reviews of controversial records of Slender-billed Curlew and Louisiana Waterthrush.

Britain During my time as secretary of BOURC I saw every file on a first for Britain up to my retirement in 2013. The standard of almost all files was very high. Although the committee was sometimes criticised for being slow, it is the case that decisions taken too quickly are more likely to be problematic. In maintaining the British List, BOURC has to consider taxonomy, identification and provenance. Contrary to some statements any previous record can be reviewed, including those placed in Category E.

Determining the status of species on the list also requires occasional reviews of historical records: the rarer the bird, the more significant each record, and we have a lot more information available to us than many previous assessors. At both county and national levels it is clear that determining first records of rare species is important. The alternative ‘voucher’ system sometimes proposed would quickly prove unworkable.

County The LROS records committee maintained consistent high standards, and undertook a review of historical records as part of the preparation for publication of BLR in 2009. As committees should, it erred on the side of caution.

Do we need committees? Although committees have their critics, it is unclear that there is a better alternative. Collective decision-making by a body of experienced individuals has a proven track record, and as already noted the vast majority of their decisions stand the test of time. One of the problems with many historical records is that they were assessed by individuals, not committees.

How many? Many countries manage with one committee, and the same might be possible in Britain (though Britain does attract relatively large numbers of rare birds, so assessing their records involves a significant workload). It is still unclear what BOU will decide about its approach to taxonomy, which is an unfortunate vacuum. The assessment of historical records is an area which should preferably be informed by dedication and experience. I have occasionally heard suggestions that we should simply disregard all Category B records, which would be irresponsible.

In the absence of a better alternative, we should support those who serve on our records committees. I’d go further: we should applaud them.

Peacock, Rutland

Peacock, Rutland

Since my last update there have been a few more changes in the fortunes of our local butterflies.

The second brood of Small Copper appeared  at the end of July, but Common Blue has been scarce and did not begin to appear until 5 August. Holly Blue continues to have a good year, but I have not yet heard any reports of Chalkhill Blue from Bloody Oaks – if the colony has died out it will have appeared and disappeared again within the short period of the RBA.

Purple Hairstreaks are having a good year, and Painted Lady has appeared in small numbers (though as last year I have not yet seen a Clouded Yellow).

Fluctuations in populations are to be expected – numbers of many species seem relatively low this year. As national statistics show, however, the general trend for many species is disappointingly downwards.

Plate from Coleman 1897

Plate from Coleman 1897

Whilst clearing out my library recently I noticed a copy of the revised (1897) edition of Coleman’s ‘British Butterflies’. Written and illustrated by the author it is a remarkable work, and the revised edition includes this plate of ‘additional species’ reported since the first (1860) edition. They are Scarce Swallowtail, Apollo, Arran Brown, Weaver’s Fritillary, Purple-edged Copper, and ‘Tailed-Blue’. Coleman himself clearly had doubts about both Arran Brown and Purple-edged Copper, but appears to have believed the former occurrence of Scarce Swallowtail (including caterpillars in the New Forest) and Apollo, and late-19th century occurrence of Weaver’s Fritillary and Long-tailed Blue.

Nowadays only Long-tailed Blue is considered to have a sufficiently credible provenance (and indeed occurred in some numbers in both 2014 and 2015). The problems associated with imported birds which were fraudulently claimed to be British during the late 19th and early 20th century are more far-reaching than often realised, and would have been even more acute in the case of butterflies and other insects which could be imported very easily.

Painted Lady, Rutland

Painted Lady, Rutland

Over the years whilst watching waders at Holbeach Marsh I looked for Broad-billed Sandpiper without success, so at the beginning of the week I took the opportunity to visit Frampton Marsh where the Broad-billed and Pectoral Sandpipers both gave good views.

This afternoon I visited Bloody Oaks for a couple of hours: no blues yet but both fritillaries and this Painted Lady nearby at Empingham. Also the Purple Hairstreak below which must have travelled a little way from the nearest oaks.

Two more months remain for significant mapping before the RBA winds down and I begin writing it all up over the winter. Please let me know if you have any significant records.

Purple Hairstreak - a typical view

Purple Hairstreak – a typical view

Purple Emperor, Rutland

Purple Emperor, Rutland

Sometimes you just have to believe. The key to finding Purple Emperor is sallow, not oak. To be honest I had given up hope of finding this species in Rutland, and my visits today were routine rather than targeted. Then this appeared along the ride into Stretton Wood. There was an anecdotal record from nearby Stocken in 2014, and there are lots of sallows in Stretton Wood, so we should keep looking.

The rest of the morning was inevitably something of an anti-climax. There were Purple Hairstreaks at Stretton and also Pickworth Great Wood, where I also noted three or four Silver-washed Fritillaries and two Variable Longhorns.

That heart-stopping moment, the 'shark's fin' on the ride...

That heart-stopping moment, the ‘shark’s fin’ on the ride… 

Apollo, France

Apollo, France

Here are two of the high altitude species which we saw during our stay in the French Pyrenees. The Apollo is widespread but tricky to photograph. We found the Gavarnie Blue in three areas, of which the best was the valley behind Lac des Gloriettes.

Other species of note included more former British or rare migrant species: Mazarine Blue, Bath White and Long-tailed Blue.

Last but not least, we also saw this Pyrenean Brook Salamander in water so clear that it could be photographed.

Gavarnie Blue in typical habitat

Gavarnie Blue in typical habitat

Pyrenean Brook Salamander

Pyrenean Brook Salamander

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