I knee-d a Purple Emperor

The first Purple Emperor of the day landed on my shorts and wandered around my knee for a few minutes, no doubt remarking on my sweaty qualities.  Frustratingly, no amount of contortion could get the beast into focus through the camera lens before it soared off over the woodland canopy.  So began my walk around Broxbourne Woods this weekend.  After the first Emperor of the day they became decidedly scarce for a while and it seemed I would not get a decent photo, unlike Silver-washed Fritillaries, which were everywhere.  I have walked these woods since the 1970s and never have they been so numerous. They were distinctly hard to find in the 1970s-1990s but now every sunny glade seems to have a few. A remarkable change in status.  Likewise the Purple Emperor.  In the early days, every White Admiral was scrutinised in the hope of finding the Emperor.  Now almost full circle, I saw more Emperors than Admirals on my two hour walk.

At Danemead, a Herts and Middlesex Wildlife Trust nature reserve within the woods, Broad-leaved Helleborines were just coming into flower and the exit holes of Goat Moths were still evident in the small group of old trees that they have inhabited for decades.  Back in the depth of the planted conifers, a family party of Firecrests mingled with a large mixed flock of tits and 9 Crossbills chipped away from the top of a Larch.  On the final stretch back to the car park, Purple Emperors at last began to perform; a couple zooming around large sallows, a couple more taking moisture from the damp path and a final individual sucking away at a gate post.

Photos: my feet, Silver-washed, White Admiral and PE.

 

The results show

The end results of habitat management often seem to pass by in a flash in June.  This week offered the opportunity for a bit of speedy site checking to see how target species were faring.  A quick look at North Warren found 40+ spikes of Sand Catchfly, maintained in its favoured bare patches by a bit of raking and over-zealous cyclists.  Who says disturbance is bad?  A whizz by Minsmere produced a distant Savi’s Warbler and, more impressively, a Bittern booming out in the open in front of the Bittern hide, where else?

Fen Orchids are just coming into flower.  The remaining Norfolk plants are found on just four sites, with the majority now under the management care of the RSPB.  Since taking over the management of Sutton Fen, experimental cutting of 80 blocks of fen on a variety of rotations has seen the number of Fen Orchids rise, with an estimated 1,200 plants last year.  Other fen specialists such as the Round-leaved Wintergreen and Crested Buckler Fern seemed to be doing okay.  Shallow turf ponds have also been cut to re-establish early successional conditions and now have the Shining Ramshorn snail in residence.

Cranes are busy at their usual sites, with their usual mix of problems.  One pair had already lost two clutches and have probably given up for the year; others have young chicks in tow but still are a long way to fledging.  The breezy conditions were not ideal for Swallowtails but several were seen briefly at both Sutton and Strumpshaw Fens.  Much better was a ready to emerge pupa pointed out by the warden.

Northern snippets

Choughs, The Oa and a fat, juicy tipulid larva.

A welcome change of scenery last week looking at reserve issues on Islay, with The Oa and Loch Gruinart being the main sites visited.  An Otter in the bay below the campsite at Port Charlotte was a good start.  Management for Chough was one focus of the visit.  They prefer places with short, grazed pasture, less than 5 cm in height, and soft soils where they can probe to find food.  A specialist feeder on invertebrates, they will take beetles and their larvae, fly larvae (especially tipulid (Cranefly) larvae), ants, their grubs and pupae, and spiders.  Dung invertebrates are an important source of food.   Such food resources can be patchily distributed, as we found by sampling various areas of turf but we did turn up some particularly juicy tipulids in a key feeding area.

Marsh Fritillary butterflies are locally frequent on Islay. Attack by parasitoid wasps appears to have an important effect on the population dynamics of the butterfly and may help to explain its requirement for large habitat patches. Two parasitiod wasp species, Cotesia bignellii and C. melitaearum, are present in the UK  and are of conservation importance in their own right, one being specific to the Marsh Fritillary. Studies suggest that the parasitoid and its host may have a shifting metapopulation distribution, with the butterfly 'escaping' parasitism in some areas by dispersal and colonisation, with local extinctions occurring in other areas.

A Marsh Frit caterpillar with cocoons of emerged parasitiod wasp larvae.

Highlights of the trip included 30+ Chough, 6 crekking Corncrakes, 4 Golden Eagles, Hen Harrier, Tystie and Great Northern Diver.  Loch Grunart produced Corncrake and Quail calling together in front of a pair of Whooper Swans.  As well as an approachable flock of 20+ Chough, Ardnave Point also produced a typically tame migrant Dotterel.  And all this sandwiched between a daily menu of various local delicacies; from full Scottish breakfast with ‘square’ sausage and tattie scone through to sampling the local whiskies.