Following on from our yellow wagtails and green sandpipers of last week on the washland, we have seen another migrant pass through the reserve this week- our site manager Dave saw three wheatears on 3 September on Joist Fen South, and we are still seeing swallows and house martins in the skies above the reserve, with the odd hobby too. Yesterday a lunchtime walk rewarded me with a hobby, a kestrel and a little egret over the washland, whilst the great white egrets (up to three) tend to keep to the wilder western end of the reserve around Joist Fen.
Talking of passage migrants, we had a reliable report from a visitor of a brief visit by an osprey at lunchtime on 26 August over the washland, later seen at around 15:00 over New Fen. The osprey autumn migration is quite protracted and lasts weeks, beginning with adult females, then males, and then the young birds. When they stop at sites such as Lakenheath they are often just looking for a fish to keep them going, a few hours rest or perhaps somewhere to spend the night, before they continue south. They will cross as little sea as possible, often land-hopping down through France, Spain, Gibraltar and then will follow the West African coast as far as it takes to find a good, safe fishing spot.
But, far from west Africa, Joist Fen South continues to offer the best chance of seeing bitterns and cranes, though they are keeping a bit of a low profile at the moment. It is more to do with the time of year than anything else, so if you do see these on your visit, we’d love to know! Pop into the Centre and tell us or via social media when you get home. One of our regular visitors got good views (and photographs) of a bittern and a water rail too:
Photo credits: Water rail and bittern by Matt Walton
Despite the cooler mornings, we still have good numbers of the summer stalwarts of the insect world, especially during sunny spells. Red admirals are probably the commonest butterfly on site, but comma, peacock and painted lady are still frequent too. As well as the usual flowers, at this time of year butterflies can be partial to the sugars in ripe fruit, such as this very freshly-emerged speckled wood I found last week. A proboscis that can sip nectar is also good for blackberry juice! Another butterfly to look out for will be the brimstone- they have a small emergence in early autumn.
Photo credit: Speckled wood on blackberries by Heidi Jones
Almost anywhere on the reserve at this time of year we get the odd sighting of a willow emerald damselfly (see photo) but these are so tricky to spot that I expect they go under-recorded. Their slenderness and colouration makes them almost invisible unless the sunlight catches them as they flutter around- perched up they are camouflaged perfectly. Migrant hawker, southern hawker, and ruddy darter are still plentiful, and common darter numbers are increasing- they often peak in autumn a little later than ruddies.
Photo credit: Willow emerald damselfly by Heidi Jones
Treasures of the moth trap this week included a very flighty but pretty latticed heath, a day-flying moth that is also attracted to light, a large thorn, several blood-vein, burnished brass, small emerald, and three poplar hawk-moths. Our commonest moth of the night, was, as usual, setaceous hebrew character with 90 counted from the trap on saturday morning. We set it twice over the weekend but friday night was the most productive, probably due to warmer, cloudier conditions.
Looking ahead, the Met Office predicts pretty good weather for the weekend- sunny spells on both days, if a little cooler. The wind direction is northerly/ north westerly and this could favour more passage migrants, whilst sunny weather will keep the butterflies and dragonflies on the wing. So it looks promising if you’re planning to visit!
As always, we have lots of activities to keep children busy- spotter sheets (£2) and explorer backpacks (£3) can be hired from the visitor centre and are a great way for young minds to enjoy a trip around the reserve! Hope to see you soon.
by Heidi Jones
Visitor Experience Officer
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