Armstrong’s Wood Boxes Update: 30/12/2020

The Autumn inspection on 11th. October was a quiet affair with just me and Coral Edgumbe (social-distanced by a 10ft. Ladder – she was at the front and I brought up the rear!) looking at all the bat boxes, while Simon and Rosie Richardson went off on their own to do the Dormouse boxes.

We replaced a couple of the wooden boxes, and found just one Noctule and one Brown Long-eared bats in the others. In the six hanging boxes there were 6, 3, and 2 Soprano Pips. And one Soprano Pip in one of the chainsaw slabs.

But in the beginning of November I had an email from Gemma Crow, the CWT Reserves Warden letting me know that she had received a message to say that one of my boxes had fallen down. When I went to investigate I found that the last box I had hung up in the last tree on the top ride had come down, fairly soon after I had hung it up in the October visit. I couldn’t tell whether it was squirrel damage or just some rotten courlene rope I had used. Anyway, I took the chance to separate this box, AWD, from the nearby one which has had the breeding colonies in. So I “lynched” it over a bough on another Oak tree about 50m further east along that top ride. While I was at it, I looked at the other boxes from the ground. The only other bats were 2 unidentified in one of the chain-saw slabs and one Soprano Pip in another. None in the hanging boxes.

Finally, yesterday, 30th. Dec.,  Nic Harrison-White and I visited and took a ladder to hang AWD from a stronger strop (I’ve tried wire this time) and take down the “lynching“ rope. One of the hanging boxes above the leat had a single unidentified bat, and one of the chain-saw slabs had a single Soprano Pip and the hanging box in the corner of the second field, AWE had a single Soprano Pip.

So bats are still happy to hang around in these insulated boxes during the depths of winter. But, alarmingly, one of the chain-saw slabs had a Woodpecker shaped hole drilled in it just about where a bat would be inside! So any replacements for these are going to need some exterior protection from birds.


I’ve several times had some of these insulated boxes hanging in my barn at home, where I often get a Long-eared night roosting.  But only once did I ever see a day roosting bat in any of them. But it seemed pointless keeping them at home, so back in October I hung one in some woods on the Coldrenick Estate, just north of the A38 about midway between Trerulefoot and Liskeard. It will be interesting to see what this one attracts.

Moths in December from Mary Atkinson

The Gem moth, female.

Part of the unsettled weather we are having at present is giving us pulses of warm air coming up from the south, bringing some migrants, particularly to the southern part of Cornwall. Apart from the usual trickle of Rusty-dot pearls and Dark Swordgrass, there’s always a chance of less usual species, for example the Gem which will come to light. Widespread on the continent, it is a great wanderer. The sexes are dimorphic as shown in the pictures.

Gem moth, male.
Dark Chestnut.

Dark Chestnut, less common than the Chestnut, this richly coloured moth, aptly described by its name, can be seen at light or often feeding on late ivy flowers. Different clumps of ivy open at different times in the autumn, thus giving an extended season when insects are able to nectar on this valuable food source.

The Dark Chestnut is single-brooded, appearing from November to February, and can be differentiated from the Chestnut because the tips of the fore-wing are pointed or even slightly hooked. See pictures. Care is needed however,  because worn specimens may well have this feature abraded and less obvious. The leading edge of the Chestnut wing is rather fuller and slightly rounded. Practice helps.


The books say that the Dark Chestnut can be commoner than the Chestnut but I don’t find that is the case here in east Cornwall, although both species are increasing their distribution throughout the UK. Bear in mind that increased moth trapping even through the winter months when these moths fly, may have some effect on the numbers of records collected.


Moths to look out for in November ’20

Merveille du Jour

A typically flamboyant Victorian name, but the Merveille du Jour deserves it. A master of camouflage, this single-brooded late autumn moth is relatively common and widespread. It lives on oak, overwintering first as an egg, and, refreshingly, it doesn’t seem to be declining.

November Moth.

This moth is lumped with the Pale November Moth. The demure little geometer echoes the misty grey of the season. Another single-generation, late autumn moth, it over-winters as an egg and the following spring the caterpillar feeds on a wide variety of broad-leaved trees. It is sadly declining, despite no shortage of foodstuff, but it is possibly being under-recorded because it is difficult to differentiate between very similar species within the genus.

Red-Green Carpet

This nicely-marked carpet is unlikely to be confused with the Autumn-green and Beech-green Carpets as the two last species  very  rarely occur in Cornwall. The Red-green, not uncommon, is single-brooded, appearing in the autumn, but as the females hibernate through the winter they can be seen again next spring. Happily, it seems to be increasing in number and distribution. The caterpillar feeds on a variety of trees and  the adult will come to light as well as feeding on ivy blossom in the autumn, and willow catkins the following spring.



Mary Atkinson. Oct.27th. ’20

Rowena’s fungus forays!

We planned for a foray this month but had to cancel so Rowena has been visiting the woods and taken lots of photographs. A compilation has been sent out to our members but anyone is welcome to have a go at identifying these~ all shown on our home page. There are 12 in all.

Please use the email shown on the website to send in your ideas.

3.This is the one that has been chopped down by the slideshow!



Flounced Chestnut

A handsome moth seen only in the autumn. It comes to light and may also be seen feeding at twilight on ivy blossom and fermenting fruit.

Overwintering as an egg, the night-feeding caterpillar will eat the leaves of a variety of deciduous trees in the following spring.

The new Moths Atlas tells us there have been major declines in both abundance and distribution since 1970. How often I am having to say this.

Pink-barred Sallow.

This moth like the Flounced Chestnut and other Sallow moths are well-camouflaged like autumn leaves. It’s the commonest (although still suffering substantial declines in abundance) and most widely-distributed of this group of single-brooded autumn moths. Its distribution is increasing, but how much is this a factor of more people out there trapping in the past 50 years? It would be interesting to know how many and where, are the trappers every year…..

Barred Sallow.

Another autumn moth, feeding largely on Beech here in our area although elsewhere it will feed on Field Maple which scarcely occurs in Cornwall as it prefers more limey soil and is an abundant roadside planting around Plymouth, on limestone.

This moth is nationally common and widespread and shows a long-term increase in its distribution.

Centre-barred Sallow.

This is an interesting one as it is closely tied to the Ash tree. The caterpillar emerges in spring to feed on the unopened flower and leaf buds of Ash. How will it fare as the Ash declines due to die-back? Here in Cornwall, it seems to be having a good year, even appearing in West Cornwall where there are very few records.



It’s dormouse week!

Time to celebrate 30 years of the National Dormouse Monitoring Programme:

Dormoused hazel nuts

Time to take a walk and go nut-hunting for hazel nuts opened by dormice. And please record them here:

And time to consider and think about the fact that numbers of the hazel dormice have declined by 52% since 1995.

Torpid dormouse

We still have them in Cornwall and in several of our project parishes. This week and next, a few of us will be checking dormouse nest boxes (under license) and will report on what we find.

Dormouse and nest box

Moths to look out for in September


Large Yellow Underwing

More experienced ‘moth-ers’ will wonder why I have put in this most abundant and ubiquitous moth. But I find it’s one of the most frequently asked questions about wild-life. Such as “I got quite a jump. I was weeding and this big brown thing scuttled off like a mouse. I could have sworn I saw a flash of yellowy-orange…”

Yes! This was a Large Yellow Underwing (known as a short-cut as ‘pronuba’ by moth-ers, as that is its specific name, Noctua pronuba).

As the pictures show, its upper wings are very variable and the lower wing is rarely seen except briefly in flight.

It has a long season, from June till October, peaking in late August so it may completely dominate the catch in a light trap at that time. It can also be seen nectaring at dusk of a variety of nectar-rich flowers like Buddleia, as well as being disturbed by day.

Its caterpillar, a bulky rather grub-like greenish brown, feeds on a wide variety of plants.

Just two variations of Large Yellow Underwing

Treble Bar

This is a distinctive moth, more often disturbed by day although it will occasionally come to light. Described in the books as ‘common’ I would interpret that as ‘widespread’. I scarcely ever see it but it can be seen in open heathy grassland  in June, but here in the south it has a second, September generation.

Its caterpillar feeds on St Johns-wort.

Frosted Orange

A real sign of impending autumn, this moth will come to light or will settle on the vegetation nearby. Like a dollop of marmalade, it is another of the golden autumn-leaf coloured moths that we see as the leaves start to change colour.

It can be seen in a wide variety of habitats in the countryside.

The caterpillar is hardly ever to be seen as it feeds and pupates inside the  lower stem of robust plants such as thistle, foxglove, hemp agrimony.


Moths to look out for in August


This is a very distinctive moth with black and a few yellow spots on a white background. It has a single generation in the summer and will come to light or can be seen resting flat on foliage during the day. It’s about the size of a Gatekeeper. Its larval foodplants are many hedgerow shrubs and fruit bushes.

It is a common resident, widespread, and undergoing an expansion of its range in northern Scotland.


This moth, in spite of its name and black and white pattern, is no relative of the previous moth. It’s nearly half the size of the Magpie and is a member of the Crambiidae or Grass Moth family. These are ‘Micros’ although the Small Magpie is one of the larger Micros.

The ‘micros’ are so named not so much for their size but  for their position in the taxonomic ordering of moths and butterflies; they are more primitive in the structure of the adults, some of whom do not even have mouthparts.

You can see from the pictures these two moths shouldn’t be confused.

The Small Magpie is also single brooded and can be seen at light and disturbed from foliage any time between May and September.

Its caterpillar feeds inside the folded up leaf of nettles, Woundwort and Mint. It is common and widespread.


This species is extremely variable. Four of its forms are shown here.

To complicate matters further, it was decided in 1983 that in fact it was two distinct species but identifiable only by ‘gen.det.’ (genitalia dissection). This second species, the Lesser Common Rustic, is equally variable! The species therefore, unless gen.det. is performed by an expert, is now recorded as Common Rustic agg. (agg. being short for ‘aggregated or combined species)

Both species are single-brooded in July and August, will come to light and can also be seen feeding on flowers.

Because the Lesser Common Rustic is much less identified as a true species, the knowledge of its distribution is still very incomplete. The distribution map shows the occurrence of the aggregate species as common and widespread.

The caterpillars of both species feed in grassland.