5 -The Norfolk Damselfly, Coenagrion armatum
The Norfolk Damselfly was discovered in 1902 or 1903 (accounts vary) in, surprise surprise, Norfolk, by Professor William Alexander Francis Balfour-Browne. It was first recorded from Stalham, and was subsequently discovered at Sutton and Hickling Broads. Most accounts give the year of discovery as 1902; but unfortunately I can’t find any early accounts of the discovery to confirm or deny this.
Coenagrion armatum was approx 32mm long and its flight season spanned from late May to mid July. Visually, it resembled a Blue-Tailed Damselfly. Males could be distinguished by their ‘strikingly long, curved inferior appendages’ (Brooks, 2004) as well as the top of their thorax being ‘almost entirely black’ (Brooks, 2004). Female Norfolk Damselflies can be distinguished from the Blue-Tailed Damselfly by their ‘broad emerald-green antehumeral stripes and prominent greenish-blue patches at the base of the abdomen’ (Brooks, 2004).
There does not appear to be much information available about the decline and extinction of the Norfolk Damselfly, and some of what does exist appears contradictory. Hawksworth states that ‘The population went into decline in the 1950s as the breeding sites began to dry up and became over-grown with reed, sallow and alder carr; this species was last seen in 1957’ (Hawksworth, 2001). Conversely, Tait & Tayler claim that ‘the Norfolk Damselfly was unable to survive the pollution of sites where it had previously thrived’ (Tait & Tayler, 2005). A slightly different view comes from Maclean, who quotes dragonfly expert Cynthia Longfield as saying the Norfolk Damselfly was ‘exceedingly rare’ in 1937 – which seems counter to Hawksworth’s view that declines started in the 1950’s. Maclean also adds the interesting point that the restricted range of the damselfly might indicate that it was in fact a ‘relatively recent migrant from the near continent’ (Maclean, 2010).
I personally wonder whether Tait & Tayler have possibly confused the fate of the Norfolk Damselfly with that of the Orange Spotted Emerald, which certainly seems to have met its end at the hands of pollution (perhaps the subject of a post another day?).
The idea that the Norfolk Damselfly was a recent colonist is an interesting one; it would certainly be a good reason for its restricted range in the UK. As the European range of the ‘Norfolk Damselfly’ is from the Baltic eastwards, recolonisation does seem unlikely. However, a population was rediscovered in the Netherlands in 1999, and only approximately 120 miles of North Sea separate the Netherlands from East Anglia. So if the population in the Netherlands was to increase, and given some suitable vagrant weather, and if some suitable habitat was to exist somewhere in the south-east of England, then possibly maybe perhaps the Norfolk Damselfly could recolonise. Lot of ifs.
Brooks, S. (2004) Field Guide to the Dragonflies and Damselflies of Great Britain and Ireland, British Wildlife Publishing, Hampshire.
Hawksworth, D. L. (2001) The Changing Wildlife of Great Britain and Ireland, Taylor & Francis Ltd., London.
Maclean, N. (2010) Silent Summer: The State of Wildlife in Britain and Ireland, Cambridge University Press, Cambridge.
Tait, M & Tayler, O. (2005) The Countryside Companion, Think Publishing, London.