Signal Crayfish

beckClearing away vegetation from the side of this stretch of Coxley Beck, a neighbour came across what I guess must be a signal crayfish, a North American species which has become established in this country and which is ousting our native white-clawed species.

My neighbour described a living specimen he came across as ‘large’ and brown. He then turned over some vegetation and found a dead individual, which was upside down, revealing red markings on the underside of its claws.

This is bad news for any white-clawed crayfish that might have been present in the beck. A friend who remembers the beck as it was before any of the houses were built on the beck side of the road told me that there were crayfish there, but this would be about fifty years ago.

But perhaps there is some potentially good news as signal crayfish are eaten by otters. One of the members of our local natural history society, Wakefield Naturlists’, Francis Hickenbottom, showed me a photograph of an otter pellet he’d come across at a nature reserve by the River Aire. The pellet included a number of those distinctive red claws.

Harlequin Ladybird

harlequin ladybirdThis harlequin ladybird landed on the window this afternoon. It’s probably on the look-out for a suitable site to hibernate.

A map on the Harlequin Ladybird Survey website shows how this North American species, introduced to Europe in 1988, has spread from the south-east of England. From a couple of records in Yorkshire in 2003-2004, it has now been recorded across most of the county, with the exception of parts of the Dales, the North Yorks Moors and the Wolds. It’s apparent absence here may be the result of there being fewer people to record them.

Link: Harlequin Ladybird Survey