HAVING THE BLUES

My early spring butterfly transects (surveys) have thrown up the usual native overwintering suspects, namely the likes of the Peacock, Brimstone and Small Tortoiseshell butterflies.  Our fantastic reserve is home to many types off butterfly that come to feast on the variety of wild flowers.  Notable visitors/residents include the Marbled White, Green Hairstreak, Small Copper and the Brown Argus.  None are as striking, mysterious or unique as the Blues that make the Hill & Holes their home. 

The Chalkhill (on the wing Jul-Aug), Common (May-Aug) and Holly Blue (Apr, May & Aug) butterflies are to be found at various periods on the Hills and Holes.  The Chalkhill though not rare is normally confined to chalky downs of Kent, Surrey and Sussex.  We are privileged indeed to have a colony of Chaklhill so far north.

What makes these butterflies truly fascinating is their symbiotic relationship with ants.  To varying the degrees, ants will protect the caterpillars of the Chalkhill and the Common, escorting it back to their nests at the end of the feeding and then back out again.  In return the ants receive a sugary nectar from the caterpillar.  Even when the Chrysalis is formed, it continues to provide nectar for the ants that guard it.  When it’s time for the butterfly to emerge, a final shot of liquid is released, causing scores of ants to surround and guard the Butterfly at its most vulnerable stage.  

The Holly Blue lays its eggs on or around the fruit of the Ivy and Holly.  There are few tree climbing ants in Britain, therefore Holly Blue does not generally have the same protection afforded to the other two butterflies.  This leaves the caterpillar vulnerable to parasitic wasps.  The Blues are just a few of the many fascinating types of flora and fauna found at the reserve.  

As foot note, I just want to thank everybody for avoiding the wildflower exclusion zones which have been set up on the reserve.  These are there to protect rare plants like, the Pasque Flower, Man & Frog Orchid, Rare Spring Sedge and the southernmost example of Mountain Everlasting.

Steve Bighi, Natural England Warden BHH.