Skaters on a garden pond

April 14th 2015

Skaters on a garden pond

On 10th April 2015, I had a quick look at the small garden pond belonging to our neighbours, John and Emily Ross, at Nedd (NC1331), which earlier in the year contained at least 50 clumps of frogspawn. There were tadpoles in plenty, but also a lively raft of pond skaters Gerris sp. The identification of these water bugs requires close examination, so I collected one.

It proved to be a moorland pondskater Gerris costai, typically found on small moorland pools. The photographs are of what I take to be males; the females are darker and larger (up to 13mm). Adults hibernate on land and then, in the spring, fly to suitable water bodies to find mates. They prey on insects trapped on the surface of the water, grasping them with their front pair of legs, whilst the middle pair are deployed as oars and the hind pair as trailing rudders. A dense coat of water-repellent hairs covers the whole of their bodies, apart from the ends of their legs, which dimple the surface film.

The moorland pondskater is found right across the Highlands, but this may be the first record from Assynt.

Ian Evans

Moorland pondskater Gerris costai Nedd. Photo I. Evans
Moorland pondskater Gerris costai Nedd. Photo I. Evans
Moorland pondskater Gerris costai Nedd. Photo I. Evans
Moorland pondskater Gerris costai Nedd. Photo I. Evans

Report a Sighting

Recent Sightings

Grasshopper Warbler

single 'reeling' bird, Little Assynt Tree Nursery (Val Badger) (24/04)

Blackcap

single singing male at beginning of path to Kirkaig Falls, Inverkirkaig (Gwen Richards) (24/04)

Speckled Wood butterfly

two butterflies on Torbreck croft (Gwen Richards) (24/04)

Stoat

single animal climbing up house drainpipe, Clachtoll (Susie Bower-Browng)  (24/04)

Cuckoo

two birds seen and heard Drumbeg peat road (DAH) (23/04)

Chiffchaff

single bird singing Cnoc Glas, Drumbeg (DAH) (23/04)

Black-spotted longhorn beetle (Rhagium mordax)

single in Achmelvich garden (Richard Evans) (22/04)

Palmate Newt

two in Loch Leathad a'Phris Droighinn, Clachtoll (Ian Evans and Gwen Richards). One of these was a male in breeding condition. (22/04)

Map