Summer surveys at Luckett

We started on the Saturday evening with small mammals and bats, then moths!

Thanks to Cornwall Mammal Group for the loan of their traps which Mary & Dave set around the mining areas. Five footprint tunnels, (a very recent purchase) were placed in a bit of a rush before we all assembled to hear about the new bat detectors, which we have purchased thanks to a grant from a local foundation. Tony explained how bats emit sounds in different ways and for different reasons (social calls, echo-location) and then went on to explain how the different detectors work.

Learning about the Echo touch meters             Bat detectorists on the bridge 

The Echo Touch meters are 'just' a microphone that fits onto a phone or tablet but the app that is downloaded, reads the data and displays and saves sonograms of the sounds; produces the sounds at a level that we can hear and also provides a clue as to the identification and that's when it gets interesting.... we are still learning! Four definite IDs plus one visual and one questionable. Soprano & Common Pipistrelle, Daubenton's, Noctule then a large and seemingly silent bat flew around the trees (was probably a Brown Long-eared). The Echo meter flagged up Brandts bat and well, we don't really know, would need more supporting evidence such as past records but at least we have the sonogram recording for future research.

And then there were the moth recorders, here is Mary's report~

'We ran four traps all night on the Luckett mine site, two Robinson traps, one with a e 125W mercury vapour lamp and the other with two 15W Actinic lamps. The third trap, a Skinner, had a 14W green Synergetic tube and the fourth trap was a simple Actinic light. Two traps were placed at the west side of the site in secondary woodland and two were on the eatern side in heather/gorse/birch vegetation which has established over old mine waste. The night was mild, quiet and partly cloudy, with a waxing half moon.

Vast numbers of midges made it too unpleasant to stand by the traps so they were left to their own devices through the night and opened up for identification and release the next morning. 

Canary-shouldered Thorn

A small demonstartion of some of the more interesting and colourful moths was set up in the morning to show before they too were released. The Hawk Moths (Poplar and Elephant) and the huge Oak Eggar always make an impression.

Over 900 individuals of 105 species (two or three more yet to be identified) shows the benefit of running several traps on one site. Apart from an overlap of some species, it was, as usual, interesting to see how the traps' catches varied. 

Among the more interesting species were Bordered Beauty and Barred Yellow and the most abundant included Dingy Footman, July Highflyer, Black Arches and Mother of Pearl.'      

Mary Atkinson

Thank you Mary for collating that and to all who administered the traps! Quite a sight on Saturday morning to see tables covered in small containers being examined closely with ID books at the ready.

The mammal traps yielded two adult wood mice and one common shrew (below left, photo DGroves) ~ all good weights and condition. Only one of the footprint tunnels yield results in the form of two pages of small footprints! No hedgehogs but two tunnels have been lent out to group members to use in their gardens and we have more if anyone else would like to try one out.

Common Shrew DG                Small mammal footprints 

It was now beginning to get rather hot so a smaller group set off with Caroline to the relative shade of the mining site itself. We did record butterflies; we did see some drama on the settling beds where grasshoppers were providing substantial meals for Labyrinth Spiders but the birds were nearly silent in the midday heat and most insects were found near to the stream.

Spider and grasshopper                   Labyrinth Spider                Spider watching   

We had agreed to do a formal fifteen minute count for the Big Butterfly Count so returned to the grassy car park by the stream. I heard Richard say 'Is that a Purple Hairstreak or one of the moths up in that oak?' Before long, half a dozen grown-ups were gathered as close as they could to the oak tree with binoculars pinned on the lower branches. And yes, it was a Purple Hairstreak which kind of made the day really. Thank you Richard for spotting it an excellent start to a butterfly count!

A mystery shrub was quickly identified as the Alder Buckthorn (below left), foodplant for caterpillars of the Brimstone butterfly and near the start of our walk, someone with amazing eyesight spotted a very small but hairy caterpillar which was tentatively id'd as a Vapourer moth caterpillar but on closer inspection, this is a Pale Tussock caterpillar. What was interesting is the way it curls up and uses its hairs as a spring to 'jump' quite a distance. See below right.

Alder Buckthorn in fruit                   Pale Tussock mother caterpillar (SM)

More pictures may yet appear~ yep, some more of the moths, thanks Sue!

 Oak Eggar moth (SM)       Marbled Green moth (SM)       20 or Many Plumed moth (SM)

 Thank you to all for supporting this survey ~ please check species list below to see what I've missed. The complete moth list is not included but will be sent to Caroline to add to the mining site species list.

 

Species Seen:
Mammals: woodmouse, common shrew, rabbit, signs of badger. Bats: soprano pip, common pip, daubenton's, noctule, brown long-eared and ??brandts. Birds: nuthatch, robin, blackbird, house martin, swallow, grey wagtail, collared dove, house sparrow, goldfinch, wood pigeon, blue tit, great tit. Brown trout. Labyrinth spider. Insects: Golden-ringed dragonfly, beautiful demoiselle, a hawker dragonfly, hornet, common carder and buff-tailed bumblebees, green leafhopper. Butterflies: red admiral, silver-washed fritillary, gatekeeper, speckled wood, meadow brown, brimstone, small copper, peacock, green-veined white, large white, ringlet, purple hairstreak, comma, small white, fanfoot moth. Alder buckthorn and Broad-leaved Helleborine.