Scarce Chaser

Key Sites: The Scarce Chaser has recently colonised the River Nene in Northamptonshire. The best sites are along the stretch of the Nene from Thrapston to Waddenhoe Mill.

Spotting: The Scarce Chaser is very likely to be confused with the Black-tailed Skimmer (which is also recorded along this stretch of the Nene), and possible sightings of males should be confirmed against the following list of characteristics. There are differences in behaviour, appearance and habitat requirements that should give clues as to identity: the Black-tailed Skimmer predominantly rests on or close to the ground, while the Scarce Chaser perches on vegetation over water and hardly ever rests on the ground; the Scarce Chaser typically emerges two weeks before the Black-tailed Skimmer and is likely to be in mature blue form (males) just as the Skimmer is emerging; the Scarce Chaser is principally a riverine species while the Skimmer prefers standing water with plenty of exposed ground; the Chaser has black diamond patterns to the base of its wings exactly like those on the Four-spotted Chaser and Broad-bodied Chaser (another similarly coloured species), the Skimmer lacks these.

County Status: A regionally important species and national rarity. Breeding established in 2006.

Libellula fulva

Male, River Nene Fotheringhay July 2005

Above Left: Immature female, River Nene May 2006.

Above Right: Mating pair, River Nene June 2006