On Friday (1st March) I continued my Brown Hairstreak egg surveys of the Knepp Castle Estate Wildland project area. The first three hours were hard going, with only a single find over a wide area, despite it being blessed with plenty of blackthorn. Although browsing pressure is undoubtedly high, this was well below expectations. A welcome relief from the growing boredom was provided by a pretty Drinker moth caterpillar, snuggled tight up against a blackthorn stem. It won't be long now before it stirs from its deep slumber.

With only a dozen eggs found over six hours, spread over two visits, I was relieved to find a hotspot in the last hour, situated only a couple of hundred metres from a group of master trees I discovered during the flight season. Most of the blackthorn suckers had been nibbled back to a height of less than 40 cm, but they were liberally sprinkled with eggs. I found 23 along a 30 metre section, including a double and a treble. Bearing in mind that egg numbers drop off significantly by late winter (predation) and that many would have been lost through browsing, this is probably the work of quite a few female butterflies. The image shows how close the pair of eggs came to being deer fodder.


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