Our resident woodsman Finch writes:
We have started a biological recording program to collect baseline data for the woods - it will help us gauge the successes of future woodland management works.
One group of insects we are looking at is butterflies. Having quite specific dietary requirements as caterpillars, butterflies can act as good indicators of healthy woodland ecology. Around three-quarters of British butterfly species live in woodland but few species’ larvae actually feed on trees: most feed on grasses and herbs amongst the ground flora.
By keeping the woodland succession in cycle through coppicing and ride management we can maintain the availability on the food plants and the presence of butterflies’ required habitat.
The first butterfly sighting of the year was a comma on January 16th. It had found its way between the layers of my tent and stayed for a few days in deep torpor.
February was particularly cold. It wasn't until March that we saw most of the hibernating species take to the wing: brimstones and peacocks flying on warm days, as well as the early emerging orange tips. They synchronised with the flowering of cuckoo flower, a favourite foodplant of theirs and mine.
Typically, surveying for the UK Butterfly Monitoring Scheme would begin in April. But spring came late this year and there was rarely a day sunny or warm enough (over 17 degrees) to see anything so my survey transect was empty.
As the waves of heat hit us through summer, the shade of the wooded tracks seemed to not be the ideal place to find butterflies. The chosen transect - a survey line across a habitat - covers a mile-long east-west track. It goes through mature woodland, dense planted areas, future coppice, and overgrown rides. It showed much higher counts along the more open areas by the tracks than under closed canopy.
The most populous area was a section of track through an area of ash, hit hard by dieback. The consequential crown reduction allowed new light to the track banks, allowing the vegetation to bloom. Phases of raspberry, willowherb and hemp agrimony offer banquets for butterflies.
By collecting these observations we can look back after our coppicing, and meadow and ride management projects to compare data. To assess the benefit of our woodland work for diversity of habitats and species.
We attempted to starts in May but the mercury rarely got above 15 degrees. One transect walk was attempted 26th May but there were, unsurprisingly, no sightings.
However things did perk up in June and our most successful transect walk was on July 8th. On that walk, the woods had speckled wood, meadow brown, silver-washed fritillary and a comma. In the field were meadow browns, marbled whites and a small skipper. Other species observed informally over the summer were the red admiral, holly blue, gatekeeper, small white and large white.
Of note were:
A woodland specialist, it feeds on common dog violet.
The adult feeds on honeydew. The caterpillar feeds on the grasses brome and cocksfoot.
As an adult, it has a penchant for purple flowers such as marjoram while at caterpillar stage it feeds on fescues - narrow-leaved grasses.
A lover of nettles, unlike the butterflies above which spend their winter in caterpillar or chrysalis form, this one remains as an adult.
To be found on cardamines - the cuckoo flower being an example - and garlic mustard.