Saturday, 11 August 2012

Antlion antics

Antlion larva

With perfect timing some good weather at last arrived as we embarked on an assessment of invertebrate habitat at Minsmere this week.  Overall, there is a good diversity of habitat on this section of the Suffolk coast but the increasing numbers of Red Deer and the impact of their trampling and browsing is a concern in some areas. The trip turned into a bit of a general bio-blitz, with a good range of local specialities logged over a couple of days.

Antlions are one of those local specialities, with their characteristic larval pits even being found around the visitor centre walls.  We concentrated our search down at North Warren where a concentration of 1000+ pits had been counted earlier in the season.  Many had been washed away by recent heavy rain but a good number remained. The sand at the bottom of the pits conceals a ‘Doctor Who’ monster of a larva.  As soon as a couple of ants were ‘persuaded’ to wander around the pit edge, a deadly flick of sand knocked them down to the waiting jaws.

Plenty of Grayling and Silver-studded Blue butterflies were on the wing across the heathland, a long list of bees was steadily accumulated, and each gorse bush seemed to be home a few of the widespread Labyrinth Spider Agelena labyrinthica; their large sheet webs with a tubular retreat being very obvious.  Natterjack Toads have had a good year with thousands of tadpoles being seen earlier in the year despite the ponds being rather churned up by deer.  More by luck than skill we came across a toad posing nicely within a hollow.  Nearby we found the large Robber-fly Eutolmus rufibarbis.  This splendid beast is a scarce species of southern heathlands, especially Breckland.  It lays its eggs in slits in plant stems, with the emerging larvae entering the soil and predating dung beetle larvae.  A number of scarce plants were encountered, Red-tipped Cudweed, the diminuative Smooth Cat’s-ear, Mossy Stonecrop and two species of Catchfly: Sand and Small-flowered.  Both had just finished flowering but were still readily identifiable from the developing seed capsules.

We tried not to look for birds but managed to see a few Stone Curlews and it would have been rude not to watch the group of four Spoonbills that circled, landed and fed in front of us.  These were no doubt some of the 12 or more Spoonbills currently loafing on the Suffolk coast and includes a 2011 German-ringed nestling which spent last winter on the Essex coast.  Stone Curlews have had a moderate year.  Five chicks have so far fledged from the ten pairs in the Minsmere area.  These birds generally choose undisturbed areas well away from public access but this year one pair settled close to the visitor centre, with volunteers posted at a suitable vantage point to point them out to visitors.   

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