Insects, Sketchbook

St Mark’s Fly- Bibio marci

This species of fly is one I look out for each year at the end of April. It is called St Mark’s fly because it first emerges to perform its mating flight around St Mark’s day which is 25th April. Each year I am astonished at how accurate this date is for first observing them. They are slightly menacing black flies, flying repeatedly up and down around hedges and undergrowth in great numbers with their legs dangling almost like ropes from a helicopter. This is the time they mate and once the eggs are fertilised the female will lay them in the ground and then die. When these eggs hatch the larvae will feed on rotting vegetation and roots through the autumn and winter. Around St Mark’s day they emerge as the adult fly ready to breed. They are thought to be important pollinators. For me the St Mark’s fly is as much part of the season as the first Swallow and I love watching them dancing in the air during their short adult life.

St Mark's flies and Oil Seed Rape- watercolour in sketchbook
Male St Mark's Fly, 28th April- photograph by Jonathan Pomroy
bird behaviour, Sketchbook

Wood Warblers are back

I found a singing male Wood Warbler deep in the woods. I could hear it well before I could see it. Its song carried through the trees in the cold, still, early morning air, loud, exciting and evocative of old forest with big beech and oak trees. When I found it, it was not shy, often singing within ten feet of where I sketched. A male Wood Warbler begins its song in a display flight, gliding on fanned tail and wings to a perch where the repertoire reaches its loud trilling crescendo. The energy that is packed into this final trill is immense as the bird trembles as it delivers the sound. The performance was relentless, I watched it display over and over again, occasionally replacing the trilling song with loud clear whistling notes. Wood Warblers winter in Tropical rain forests in Africa. But a few at least spend the summer near my home and I am thrilled to hear them.

Wood Warbler- watercolour in sketchbook
bird behaviour, Swift diary 2011

A Swift return

A single Swift returned to roost in our neighbour’s loft space today. We had wonderful views of the bird arriving at about 6pm, first circling the local area then approaching the nest site which it last visited in August 2010. This is a very early bird and equals my earliest Swift sighting. Last year the first returned on 27th April. It is stirring to see the wonderful shape of a Swift again and I literally yell with joy on seeing my first! Enjoy them, they are only here for three months.

Swift studies
bird behaviour, House Martin diary 2011

House Martins return

We had some brief visits by a pair of martins yesterday. They clung on the wall at the site of one of last year’s nests which fell down in the winter on a night when the temperature dropped to -15 celsius. At the time the nest was full of roosting Wrens. They may well build another nest here but I have provided six artificial martin nest boxes to compensate especially as mud is very hard to find in this exceptionally dry spring. These martins arrived just two days earlier than the first last year.

House Martins- 21st April

Ring Ouzels, Green Hairstreaks and Ixodes ricinus!

A magnificent day on the moors today. I found another colony of Green Hairstreaks and spent a happy hour sharing their heather moor habitat. The bilberry plants on which this butterfly lays its eggs were growing at the top of Glaisedale and these butterflies are an absolute delight. They are very tame and allow very close study. The females were actually laying eggs on the plants. I also saw many Common Heath moths which fly by day. From what I have read they are particularly early this year perhaps not surprising given the warmth on the top of the moors today.
I spent the afternoon sketching Ring Ouzels at a secret location. Ring Ouzels have declined drastically in the British Isles but today I watched two pairs. They are migratory thrushes who spend the summer on our uplands and the winter on the side of the Atlas mountains. They evoke wild places and are very shy. I watched them from a respectful distance with my telescpoe and on occasion they would approach me- a great priviledge to watch these scarce breeding birds. They looked particularly elegant today, sleek in the warm weather with wings drooped. A fantastic day on the moors and the wildlife followed me home- Sheep Tick Ixodes ricinus removal after this evening’s shower, one of the perils of sketching on sheep grazed moors!

Glaisedale- 20th April 2011
Green Hairstreak on bilberry- by Jonathan Pomroy
Common Heath moth- by Jonathan Pomroy
Ring Ouzel studies- pencil and ink crayons in sketchbook
bird behaviour, Swift diary 2011

Getting ready for Swifts!

The weather seems perfect for Swifts now, but will it hold for their first big arrival less than two weeks from now? There is an inspiring website by Swift Conservation whose News page shows some amazing new initiatives to attract Swifts, including purpose built towers in Tesco car parks. My blog will feature our sightings of Swifts and their arrival back at the nest boxes and follow their breeding progress until they leave in August. In particular we will be looking out for a very distinctive partial albino Swift(depicted below)  who my son called “Patch”. It regularly prospected our nest boxes in 2010 and if it has survived the journey to Africa and back could be ready to breed in 2011- watch this space!

Swift approaching nest site- by Jonathan Pomroy
Swift approach- photograph by Jonathan Pomroy
Swift arriving with a food bolus for its young- photograph by Jonathan Pomroy
"Patch" at a nest box in 2010- photograph by Jonathan Pomroy

Green Hairstreak butterfly

A glorious drive around Bransdale this morning. In the warm sunshine we found a pair of Green Hairstreak butterflies resting on the heather. I haven’t seen a Green Hairstreak for a long time and had forgotten how beautiful they are with iridescent green underwings. This moorland colony probably lay their eggs on Bilberry the food plant the larvae when they hatch. Many butterflies were on the wing today. Back in the garden I saw Orange Tips, Brimstone, Small White, Red Admiral, Peacock and Comma.

Green Hairstreak butterfly- Bransdale

Purple Thorn

This beautiful moth was by our outside light this morning. It has a characteristic way of holding its leaf like wings. The Early Thorn moth overwinters in the ground as a pupa and emerges in spring. Until the 1980’s this moth was locally distributed in Yorkshire but it has since become widespread. The larvae can be found on many broad leaved trees and shrubs.

Purple Thorn