Find out more about some of our special butterflies from Lydia's (our Visitor Experience Officer) blog...
It’s that time of the year, the sun is shining, and the butterflies are fluttering. Here at Pulborough Brooks we have recorded 33 out of the 60 butterfly species found in the UK. Our mosaic heathland, woodland, hedgerows and meadow habitats makes it a great home for some star species including 4 out of 5 species of hairstreak butterflies. (Purple, brown, white-letter and green hairstreak).
Hairstreaks are fascinating butterflies; instead of wildflower meadows they prefer open woodland and are often seen fluttering around the treetops. Hairstreak butterflies love honeydew - a sweet sticky treat that is created by aphids – and find this on the leaves of trees. They’ll descend to the meadows to enjoy flower nectar less frequently than most other butterfly species. Let’s break the hairstreaks down…
Brown hairstreak
This is the last resident butterfly to emerge in the UK but we have now had our first sightings of brown hairstreaks for the year. They usually emerge in early August, but we had our first sighting of this special butterfly on the 15th of July!
This beautiful brown butterfly is the largest of the hairstreaks with 2 wavy white streaks on its underwing and little wing tail. It is often found in the top of “master” ash trees as adults but lay eggs on young and regenerating blackthorn on which its caterpillars rely.
The brown hairstreak was once very widespread in England and Wales but has declined severely due to the loss of woodlands and hedgerows and increasingly intensive hedgerow management. We manage our hedgerows on rotation to ensure there are always areas of young regenerating blackthorn.
Every winter we do our annual brown hairstreak egg hunt to monitor the population. Brown hairstreak eggs are only 1mm in size and if you look through a magnifying glass, they almost look like a mini sea urchin. Spotting them can be a challenge!
Brown hairstreak eggs by Phil Thornton. Adult by Sophie May Lewis
Purple Hairstreak
Purple hairstreaks are a stunning butterfly with a sheen of purple. Females are almost black with a patch of purple on their fore wing whereas the male are almost entirely purple. Both sexes are silver on the underside of their wing!
This species of hairstreak relies exclusively on oak trees. In fact, it is the only butterfly in the UK to rely on oak exclusively, from laying its eggs in the oaks leaf buds to eating honeydew in the canopy of the oak. The caterpillars of this species will sleep through the day and feed at night to avoid been eaten!
Purple hairstreaks by Pete Hughes
White-letter hairstreak
This is one of the most elusive butterflies to find in the treetops. It is named after the striking white W-shaped line on the underside of its hind wing. Although this species loves honeydew it can sometimes be seen taking nectar from bramble flowers. The white-letter hairstreak will lay its eggs on the bark of elm trees. It has suffered a decline due to the Dutch elm disease which ravaged elm trees throughout the UK.
Many of the elm trees at the nature reserve have now reached an age and height when they are susceptible to the disease and have started to die-off. To help support the small colony of white-letter hairstreak butterflies that are on the reserve we have recently planted some specially bred disease-resistant elm trees. You can see some of these along the zig zag path near the start of our nature trail.
You usually need binoculars to see this species!
White-letter hairstreak – Graham Osborne
You have a chance of seeing all three of the hairstreak species above on a visit to the reserve now, although we’re rapidly approaching the end of the flight-season for white-letter hairstreaks. For the final hairstreak species of the Pulborough Brooks set - the green hairstreak – you’ll need to wait until next year…
Green hairstreak
Green hairstreaks are the most widespread of the 5 species. Rather than specialising on one tree species or habitat they are found across moorland, heathland, woodland and grassland. They have a varied diet which includes bird’s foot-trefoil, privet and they are also partial to a bit of honeydew.
They are a beautiful iridescent green colour and are unmistakeable. We’ve been treated to some fantastic views of them this year on our heathland trail on the gorse as seen in the beautiful picture taken by volunteer Graham.
Green hairstreak – Graham Osborne
Get involved
Our friends over at Butterfly Conservation have their annual Big Butterfly Count starting from 15 July to -7 August. Over 100,000 people took part last year making it the largest butterfly survey in the world. It is incredibly important to monitor butterflies as they are an indicator species and will react quickly to environmental changes. It only takes 15 minutes to do but makes a huge difference to butterfly conservation.
Find out how to take part on the Butterfly Conservation website here
Butterfly fun at Pulborough Brooks
Our children’s activity trail for the Big Wild Summer is all about the wonderful world of butterflies and moths. Join us throughout the summer holidays and discover more about these marvellous creatures through quizzes and games!