Monday, 19 August 2013

Elm Farm

Saturday Night and Sunday Morning at Elm Farm, 17th, 18th August 2013

The four Bath Nats who joined John Paget and Ian Stapp, on a cool but mostly dry summer evening after a rainy afternoon, were in for a treat. Having watched a sparrowhawk cruising amidst the swallows and house martins gathering in the dusk, we were led across to watch the moth trap being set up and then to the barn in which the colony of around 35 Natterer’s bats were said to be roosting. We looked up to the ridge beam but could not see any activity, although the plentiful droppings on the floor beneath provided clear evidence of the bats’ presence. The coolness of the evening allowed the bats to stay well hidden, we were led to believe. We then walked out along the main path from the farm, past a small pond, to a gateway where we looked towards woodland across a grassy field, with a border of melilot, scorpion weed and quinoa, planted to encourage winter birds. While John told us about the history of the farm and its management, we watched roe deer and a brown hare. We then walked back to the main barn and were shown a superb short video film of the Natterer’s bats, which prepared us for what was to come. As the evening light faded, we returned to wait beside the Rothko-like rectangle of blackness at the entrance of the barn, which was lit from below by a red light. We listened to the crackling on the bat detectors, which Ian told us was the bats having a natter about whether the weather was good enough, but not yet ready to take flight. Just as we began to wonder whether they would do any more than just chat about it, their tone changed to a more rapid, deliberate code and we saw the first red-lit flutterers emerge and swirl around us before disappearing off into the night sky. More soon followed, the bats both exiting from and returning into the void in rapid succession, a vibrant, living firework display that lasted around 35 minutes until the last bat had left and the detectors fell silent.

Next morning, in bright sunshine, a much larger group of 18 gathered at the entrance of the farm to watch Richard Pooley examine and identify around 35 species of moths that had gathered overnight in and around the trap. Amongst the most abundant were ‘Flame Shoulder’ (Ochropleura plecta) and ‘Lesser Broad Bordered Yellow Underwing’ and amongst the most striking in appearance were ‘Spectacle’ (Abrostola triplasia), ‘Magpie’ (Abraxus grossulariata) and ‘Blood-vein’ (Timandra comae). Pride of place went to ‘Dark Barred Twin-spot Carpet’ (Xanthorhoe ferrugata). We then took a walk around the farm, appreciating the wide variety of flora, fauna and fungi to be found in its diversity of hedgerow, wetland, woodland and grassland habitats. Among the more unusual finds was ‘Choke’ or Epichloe typhina, growing on ‘Wood false-brome’ (Brachypodium sylvaticum). This fungus grows ‘endophytically’ within living grass stems, but prior to fruiting produces a tight collar of mycelium around the flowering culms, which appears to ‘choke’ them. Although it inhibits flowering, the grass responds by producing more  vegetative growth. Last but not least was a fine specimen of ‘Vapourer’ moth (Orgyia antiqua) in the hedgerow along the main path from the farm.

Richard Pooley &

Alan Rayner

Click Photos to enlarge
Blood Vein 
Common Blue
Photos by Paul Wilkins

No comments:

Post a Comment