Southern Migrant Hawkers and Scarce Emeralds - Essex

Tuesday 18th July 2017.

On Tuesday morning I met up with David D-L on Canvey Island for a session of sound recording followed by some odonata photography.

Canvey Point was our first destination for sound recording which produced 3 Yellow Wagtail30 Black-tailed Godwit, c.320 Oystercatcher, 47 Turnstone, c.20 Dunlin, 1 Whimbrel, c.40 Curlew6 Little Egret, and 6 Cormorant. Thanks to David for use of the sound recording equipment here!

Once the waders started to fly out to the mudflats to feed, we headed to our next port of call, West Canvey Marsh. At least 1 male Southern Migrant Hawker was present here, with good numbers of Ruddy Darter, and a Wall butterfly seen.

Male SMH at WCM

From here we walked to a section of ditch on the NW part of the island, parallel to Canvey Way, which has recently been identified as a prime location for rare odonata. Within the first 20 metres or so of the ditch, we encountered our first Southern Migrant Hawker of the site. This was followed by a minimum of 15 more SMH (all males) just along the first 450 metres of this ditch (which was as far as we walked). Based on what we saw here, each male tends to partol a territory of around 10-15 metres, flying back and forth and occasionally straying when a rival male enters another territory or when food may be available. The Southern Migrant Hawker is a rare species in the UK but has been established in South Essex since 2010. An absolute minimum of 18 Scarce Emerald Damselfly were also seen in this section of ditch, again all males, and a useful comparison having seen male Common Emerlads at Rainham Marshes the previous day.

Considering we only walked just under 1/3 of this ditch, there are no doubt many more individuals of both species present here. Surely there are more distributed around other ditches and marshes away from known sites in the nearby area, given the incredible numbers found in this one unlikely stretch of ditch.

We spent an hour at this site, where 1 Marbled White butterfly and 2 Blue-tailed Damselfly (with another being demolished by a Scarce Em) were present.

Marbled White

Max Hellicar.