A moth and bat evening at Armstrong's Wood

We were a small and select group but it was a good evening and much was accomplished! The evening bird song echoed through the woods and tawny owls were both heard and seen.

I hope to add a couple of photographs later on~

 Tony’s experiment was to see if it would be possible to count emerging bats from a roost in an area where it is difficult to see clearly. This is what he says:

“Counting bats out of their roosts can be fraught, especially when the exit point is not silhouetted against the sky, as in woodland roosts. So I was exercised into how we could get an idea of the size of the colony in  one of the hanging, insulated, "beehive" boxes on the top ride in Armstrong's Wood Reserve. Last year I'd estimated something like 200 bats in the box at one stage, and this year Mary and I had seen something like 100 bats in it. So I borrowed a Sony Handycam and some infra-red lights and on Sunday evening of the 11th June we set them up beneath the box to see if we could get an accurate count. Paul McNie brought along his infra-red torch and an infra-red monocular 'scope.

Paul started counting at 9.10pm and I switched on the video recorder at 9.15. I am inexperienced in this technique so it took me a while to adjust the camera and the lighting to get the best results. Eventually I was able to watch the bats emerging on the monitor screen while they were being recorded. With the right glasses on, and sufficiently zoomed-in on the box, I was able to count the bats as we went along. When one replays the action later, to get a better view, one has to replay in 'real time', because the bats move so quickly that if one accelerates the play-back, one misses the bats. So it is useful to be able to count in 'real time' as one is recording. It means that when the bats have all emerged, one has a count, without having to wait another hour to see the recording.

When the bats finished emerging we had a total count of 104 Pipistrelles, and some of the onlookers were able to confirm with their detectors that they were Soprano Pipistrelles (Pipistrellus pygmaeus). When we shone a torch up into the box to confirm all the bats had gone we could see that there were no adults left, but there were 11 pups let behind. 10 of them were still naked enough to look pink, and one was starting to get its furry coat and looked grey. So a successful count; confirmation that the bats are breeding in this box; and a successful trial of equipment that could help those with poor eyesight like myself to carry on doing emergence surveys.”

And the moths~

 Mary ran two traps, one, a Robinson style trap was placed up in the field and the other, a Skinner design using a synergetic lamp, was placed close to the entrance under tree cover. After a slow start, the count next morning revealed over 80 different species and several were new for this site. The most common was the Buff Ermine (38) and the Waved Carpet is one that is nationally scarce. The Orange Moth was my favourite!

Angle Shades; Barred Straw; Barred Yellow; Beautiful Golden Y; Bee Moth Aphomia sociella; Bloodvein; Brimstone Moth; Brindled White-spot; Broken-barred Carpet; Brown Rustic; Brown Silver-line; Brussels Lace; Buff Ermine; Buff Tip; Clay Triple Lines; Clouded Border; Clouded Silver; Common Lutestring; Common Marbled Carpet; Common Pug; Common White Wave; Double Line; Double Square-spot; Double Striped Pug; Elephant Hawk Moth; Eyed Hawk; Flame; Flame Carpet; Flame Shoulder; Foxglove Pug; Green Arches; Green Carpet; Green Pug; Grey Pug; H&D; Ingrailed Clay; Large Yellow Underwing; Light Emerald; Lobster; Marbled Minor agg.; Marbled White-spot; Middle-barred Minor; Mottled Beauty; Mottled Pug; Oak-tree Pug; Orange Moth; Pale Tussock; Peppered; Pinion-streaked Snout; Poplar Hawk; Privet Hawk; Purple Bar; Purple Clay; Rivulet; Sandy Carpet; Scorched Carpet; Sharp-angled Carpet; Sharp-angled Peacock; Shoulder-striped Wainscot; Silver-ground Carpet; Small Angle-shades; Small Fan-foot; Small Magpie Eurrhypera hortulata; Small Phoenix; Small Square-spot; Snout; Spectacle; Straw Dot; Treble Lines; Triple-spotted Clay; Waved Carpet; White Ermine; Willow Beauty; Agapeta hamana; Celypha lacunana; Celypha striana; Elasticha atricomella; Eudonia delunella; Long Horn sp.Nematopogon metaxella; Long Horn sp.Nemophora degeerella; Olindia schumacherana; Pseudargyrotoxa conwagana; Tinea semifulvella; Udea olivalis.




Calendar Event associated:
Species Seen:
Tawny owl and heard: song thrushes, blackbird, robin, wren, chiff-chaff.