Sunday, 3 January 2016

Rarity

It is always a thrill when I happen upon rare species or rarely seen behaviour in the wild. Whilst I'm not particularly obsessive about chasing rarity for it's own sake, I am always on the look out for anything unusual.

For me, rarity can mean a nationally rare resident breeding species, rare and vagrant migrant species, or regionally rare species that may be common in one county and not found in the next.

Globally, the Long-tailed Blue (Lampides boeticus) is a widespread species but it is a rare migrant to UK shores and in two of the last three years it has managed to produce late season British broods. When, in 2013 it became clear that Long-tailed Blues were arriving in southern England along a broad front, I was keen to seek it out in East Sussex.

 
Long-tailed Blue (Lampides boeticus) (female)



Long-tailed Blue (L. boeticus) (male)



Long-tailed Blue (L. boeticus) (male)



This male (below) was the only example I saw in 2015, found by Mark Colvin as we searched together at an East Sussex site.



The Four-spotted Footman (Lithosia quadra) is mainly a migrant moth to Britain but has established a breeding population in East Sussex in recent years. In June 2014, my wife and I came across a quadra larva basking on a garlic mustard leaf whilst I was looking for Orange-tip larvae. (Yes, Carol saw it first!). Whilst I could see what family it was from, I didn't make a positive identification until I got home to check the books. It was the first confirmed sighting of a quadra larva in Sussex since 1949 and then 1874 before that.

(Reference; "A Complete History of the Butterflies and Moths of Sussex" vol.4, by Colin R. Pratt).
 
 
Four-spotted Footman (Lithosia quadra) (larva basking on garlic mustard leaf in East Sussex)

  

Guide books will show that the main breeding populations for the Scarce Emerald Damselfly (Lestes dryas) seem to be centred around the Thames estuary and Norfolk. The occurrence of this species in East Sussex can at best be described as sporadic, with I believe no known or confirmed breeding sites within the county. In July 2014, I came across a male dryas on Ashdown Forest.


Scarce Emerald Damselfly (Lestes dryas) (male)
 


For all things to do with orchids, I go straight to the excellent "Orchids of Britain and Ireland" by Anne & Simon Harrap. The distribution map for the Green-flowered Helleborine (Epipactis phyllanthes) shows that it is found locally mainly in south-central England. In East Sussex it appears to be a rare plant although it may be under-recorded. In 2014 I was invited by a friend to come and see a helleborine species that appears annually beside her farm driveway. After consulting the Harrap, I was confident that we were looking at phyllanthes. In 2015, I decided to search a wider area for more plants and was chuffed to find another small group growing nearby.


Green-flowered Helleborine (Epipactis phyllanthes) from the original group.


 
Green-flowered Helleborine (E. phyllanthes) from the second group.

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