Thursday, 15 September 2011


Steve Entwistle did well to find Mersea' first small colony of the rare willow emerald damselfly at Maydays farm on Wednesday 14th. At least ten individuals were seen resting on the sunny side of a hedgerow with both males and females providing good views. A pair were seen locked in the mating wheel. The picture above shows one of the obliging females resting on an elm leaf.

Willow emeralds have begun rapidly colonising East Anglia and the south-east from the continent, since their first discovery in 2009. I believe the first Essex discovery in September 2009 was just north of Mersea at the Fingringhoe nature reserve. Such has been the spread of these damselflies, it was only a matter of time before they were found on the Island. Steve's patience and effort has been richly rewarded and generated a bit of emerald excitement!

One of the features that separate willows from other emerald damselflies can be seen in this close up of the shiny green thorax on this female. The slightly darker green "saddle"shows a pointed spur which is not present on other emeralds.

This female seems to have a browner thorax than the previous individual which was greener. The white upperside to the tip of the abdomen is also a distinctive feature.
Willow emeralds are unusual amongst most other native damselflies in that the eggs are laid in the bark and twigs of willow branches over water rather than in aquatic vegetation or in the water.

This male was reluctant to come down lower to rest like the females on the hedge but the bright green body showed up well in the sunshine. The pale brown spot on each half-raised wing is another willow emerald feature.

It is quite likely that other ponds on the Island will also have willow emeralds present too.

Following the report from Martin Cock that he'd seen 4 gannets from Coopers Beach earlier in the afternoon, I joined Steve at the end of the afternoon looking from the country park, view pictured above. Within the first scan of the sea, an immature gannet was seen flying offshore. Another two brown immatures were also seen a short while later further out over the water.

Two marsh harriers were also seen flying out at sea as they crossed from Point Clear to Bradwell. A Mediterranean gull flew past the beach while offshore 3 eiders were noted.

Steve found a spotted flycatcher near the car park in the early evening, only the second record for the Island this year. Five blackcaps were seen near the pond, willow warbler called in the cliff-top trees, 2 wheatears on the beach and a lone brent goose at the Point.

The westerly wind saw many migrants passing low over the park in the morning with 20+ siskin, 10 sand martins, 15 house martins, 150 swallows, 50+ meadow pipits all heading west.

Martin Cock saw 8 wheatears and 5 whinchat during his visit to Maydays / Reeveshall on Wednesday afternoon as well as 10 siskin flying over. In the evening a marsh harrier was hunting fields near the East Mersea road at Weir Farm.

On Tuesday at the park a hobby was seen in the evening resting for a few minutes on the mudflats. A turtle dove was seen in a hedge by the pond and there was also a report of one near the beach at Fen Farm. A lone swift was seen passing west over the park on Tuesday evening. Steve Entwistle saw 2 kingfishers at Maydays on Tuesday, the first reported sightings on the Island this year, as far as we know.

On Monday a marsh harrier flew over the grazing fields, a sparrowhawk was seen near the pond, 5 blackcaps in bushes by the pond, 2 wheatears by the beach, a goldcrest called with some tits in the cliff-top trees. In West Mersea a willow warbler was calling in Firs Chase in the morning.

An update on the resident mute swans shows that they are all well and even more puzzling, the incoming rival pair were nowhere to be seen by Tuesday and looked as if they had cleared off. The resident male who had to retreat back to the pond after losing the dispute, was later reunited on Monday with mother and their two cygnets. However the next day the mother had walked the two young ones back across the field to the dyke again, leaving the male by himself on the pond.

The moth trap was put out on Monday and Tuesday nights although catches were low due to the bright full moon, strong breeze blowing and the cool temperatures.
This smart black rustic was one of two noted on Monday night, the first ones to be seen this autumn here. On Tuesday night the first lunar underwing of the autumn was noted.

Other moths noted were brimstone, willow beauty, brindled green, square-spot rustic, flounced rustic, large yellow underwing, snout, setaceous hebrew character, frosted orange, rosy rustic.

No comments: