April and First Signs of Spring
Strange. There we were two and a half weeks into the coldest, wettest, windiest and downright nastiest April for years, some say seventy, and there I was having to close the curtains to keep the blazing sun off my laptop screen. A frustratingly brief two-day heatwave, the hottest April day since records began, soon degenerating into yet more wind and rain but nevertheless seeming to kick a dormant and expectant Spring back into life.
The signs were there right from the start with my first butterfly survey of the year on 5th. with a handful of Brimstone and Small Tortoiseshell butterflies having emerged from hibernation; but these walks are not just about butterflies and an early bee-fly was doing its hover-like-a helicopter impression and a Chiffchaff sang. Presumably this was an early migrant; although some are known to stay for the winter, particularly in the South, I hadn't heard any this Winter. Violets were in flower on the nature trail and I counted seven Buff-tailed Bumblebee queens feeding off Pussy Willow next to the viewing screen. This is a lovely tree, either a Grey or Goat Willow, I must find out which, and is a a-buzz with feeding insects at this time of year. These Buff-Tailed bumblebees, Bombus terrestris, are Queens emerging from hibernation with depleted fat stores and early flowers such as these must be a life-saver. Incidentally all these large bumblebees seen at this time of year are Queens, except for a small but increasing population of worker buff-tails being seen across the country which are continuing to nest and forage during the winter. Normally all bumblebees in a colony die over the winter, leaving an already-fertilised Queen to hibernate alone and, on emergence in the Spring, search for a nesting site and found a new colony. However, in these times of global warming some Queens of this species are not waiting until next Spring and are nesting and rearing a new colony in October or November, thus producing winter-flying small worker bees (which ironically have white, not buff tails). I haven't seen such bees at Wiinterbourne Downs, at least not yet, but I have in our garden before now possibly because there are more winter-flowering nectar-producing plants there.
Buff-Tailed Bumblebee Queen feeding off Pussy Willow on nature trail by Roy Williams
Cowslips flowers were just starting to emerge on the field reversions and Primroses were already well under way, along the Portway path for example; both of these being valuable nectar sources for early-emerging insects and, hopefully, food plants for the larvae of the Duke of Burgundy butterfly which we are trying to tempt onto the reserve. By the end of the month our first real visual spectacle on the reserve is well under way - yellow sheets of Cowslip flowers stretched across the fields in the sunshine. We see this as a success story as many of these will be from seed planted by ourselves and our brilliant team of work-party volunteers.
Cowslips in profusion By Roy Williams
Within the next few days Dandelions were flowering across the reserve. Each of the flowerheads is composed of up to 200 tiny florets, all filled with pollen, all a massive food source for insects, particularly the smaller ones. This erroneously much-maligned plant which we rush to eliminate from our lawns and immaculately-tended beds, well, we need to give it a break. I have a bit of a bee in my bonnet about this sort of thing (pun intended) and, to me, a lawn full of dandelions, daisies and white clover is a wonderful thing, the insects and their associated food chains think the same, and it even looks nice! (To me, anyway!)
However, not all nice-looking yellow flowers are welcome on the reserve. Garden daffodils had been growing on the nature trail for some years and on 14th. we had a small work party removing them. We can only surmise where they came from; maybe some happily-misguided but well-meaning visitor put them there. The nature trail was originally a railway cutting which was landfilled in the 1980's so maybe these daff bulbs came from garden waste. I guess visitors enjoyed seeing them, but they have negligible wildlife value, and take up space for more useful stuff . Next to nothing eats the foliage or bulbs, next to no nectar or pollen is produced by the flowers. In my garden on 7th. I saw a Tree Bumblebee queen (Bombus hypnorum) , probably newly emerged from hibernation and hungry, drawn to a cultivated Daffodil and trying to feed off it,climbing inside the flower then trying to gain access by nipping the outside base of the flower tube, leaving again visibly un-dusted by pollen and seeking satisfaction elsewhere, which it did (on Pulmonaria, which is brilliant, incidentally). I felt it could have done without all that distraction!
So the daffs have all gone, despite all the above it did seem a bit of a shame in a way, but they have all found good homes!
I saw a couple of Swallows on the reserve on 18th. April, some half a dozen Stone Curlew were back and Blackthorn was by then in full flower across the reserve, and putting on a very good show this year. Likewise, but on a much smaller scale, Ash trees whose bunches of tiny purple flowers, just below the black terminal buds and only on certain trees, I'd never noticed before.
Elm trees have been planted across the reserve and are now coming into leaf. These are of Dutch Elm Disease-resistant strains such as Ulmus minor ademuz, an Elm variety from Valencia in Spain selectively bred to replace varieties now virtually lost. This is one of many Elm cultivars found to be resistant to this devastating disease and also to closely resemble in its appearance and growth patterns the long-lamented English Elm. Hopefully this is the start of a long-term vision to see Elms growing across the reserve, to the benefit of the White Letter Hairstreak butterfly whose caterpillars feed on Elms and nothing else.
A young Dutch Elm Disease -resistant Elm, Ulmus minor Ademuz, coming into leaf By Roy Williams
Well here we are now at the end of April and Spring is well and truly here. From here on until about the end of September the reserve will be at its best. May's next, one of my favourite months. See you then!
Roy Williams
RSPB Volunteer Warden