Tag Archives: nature

Wicklow’s Spring Biodiversity Explosion

As April draws to a close we have reached high Spring, and this year has been a superb one. The steady weather conditions and good levels of sunlight have transformed the landscape. The shrubs and trees are beginning to bloom, adding to those of the undergrowth. This year the lilac trees have been early and especially impressive due to the dryness – in wet years the fleshy, fragrant flower-spikes rot rapidly. This year they are the magnificent ornaments they are meant to be.

Lilac blooms - Syringa vulgaris

But the undergrowth is only really getting started. In woodlands, and on the narrow lanes of Wicklow you will find intoxicating seas of Ramsons (Allium ursinum), the wild garlic. Driving along these lanes with the car window rolled down can be something of an aromatic adventure in springtime.

Ramsons or Wild Garlic

The flowering plants depend on sunlight, and in turn the invertebrates, particularly insects, depend on the flowering plants to provide serious energy, in the form of nectar and pollen. Of course, the plants are equally dependent on the insects to fertilise them so there will be more plants, and insects, next year. Away from the trees the Daisy (Bellis perennis) are one of the most important nectar-producing species, supporting every conceiveable pollinating creature, and reaping the rewards. Wild meadows are very important habitats for this reason.

A Speckled Wood butterfly (Pararge aegeria) feeds on one of thousands of daisies in a small meadow.

As the length of days and exposure to sunlight increases the number of plant species in bloom greatly increases, which in turn supports more and more pollen and nectar-dependent organisms.

This, in turn, leads to an increase in predator numbers. One of the most interesting and unusual predators of other insects is the Yellow Dung-Fly. These flies are normally seen perched on cow dung in huge numbers, where they mate, lay eggs, and attack and eat other insects attracted to the dung. However, in spring they feed mostly on pollen, because there is so much of it about, and their prey numbers are still growing. The fly in the photo is covered in pollen, having clearly gorged, probably on daisies.

Yellow Dung-Fly (Scatophaga stercoraria)

Because of predators nectar and pollen-feeders have to be able to defend themselves: in spring you will see many species of bee, all armed with potent stings.

Bombus pascuorum is a distinct bumblebee species with a very long probing tongue, which allows it to fertilise many flowers no other insects can...it is vital to the environment. Here is is seen feeding on dandelion.
Nomada bees are small, solitary species that look very like wasps, but are extremely shy and best seen feeding on apple blossom. They are quite curious and will "people watch".
A female Mining Bee (Andrena haemorrhoa), a solitary species commonly seen in spring, where they build little tunnels in lawns and meadows, with small vocanic-looking cones around them. This species collects pollen on special hairs on its hind legs, as you can see in this photo.

However, many of the bees you will see in Wicklow are not bees at all. Instead of developing toxins, many species of fly have opted to imitate bees, and it is difficult even for naturalists to tell them apart. The trick is to look at the heads: the flies have large round heads with little or no fur, and they have only stubby antennae, whereas bees always have long antennae curling from their heads.

A brilliant white-tailed bumblebee-mimic hover-fly, Volucella bombylans, feeding on Alexanders.
A stunning hover-fly, Leucozona lucorum, also feeding on Alexanders by a roadside.

However, flowers do sometimes get more than they bargained for, slugs will also happily eat pollen, and the entire flowerhead. But only very, very slowly, and very occasionally.

A beautifully-patterned Common Garden Slug (Arion distinctus), feeding on dandelion pollen.

Thanks to the abundance of nectar many insects can take time off to find mates and breed, something that would be impossible to do if they didn’t make a profit when it comes to feeding. The beautiful little Orange-tip butterflies are only with us for about four or five more weeks, so watch out for them in gardens, along roads and flower-filled meadows with good hedgerows. They are now taking the time to find mates and breed, and the sight of a pair of them dancing over hedges is a strong sign you will very soon witness a marvellous event: I saw Orange-tips mating for the first time in my life this week. They are so common at this time of year, it is strange how well they hide their social lives. Maybe they’re marvellous camouflage prevents the casual observer from noticing. However, I’m not a casual observer, so it is rare: if you do witness this event you are one of a lucky few.

A mating pair of Orange-tip butterflies perched on sedge. The male is the right way up.

The Undergrowth Comes Alive

The sunlight, and longer days are warming the valleys of Wicklow. The smaller wildlife, on which all others depend, are starting to steal the show. While strolling in a garden or along a village lane you might see a scarlet-coloured fluttering object drop from the sky and out of sight. It might appear a little later, but if not, look on the low-growing foliage for the beautiful and aptly-named Ruby Tiger moth (Phragmatobia fuliginosa), which emerges from its pupal coccoons in April and May, to take to the sky. This species employs bright colouring to warn of distasteful toxins in its body.

Ruby Tiger Moth lying low in a meadow. Beneath the forewings is a searing red underwing only usually discernible when the moth is in flight.

At the other end of the colour spectrum is the Holly Blue butterfly (Celastrina argiolus), a stunning little spring butterfly that loves to bask on wide hedgerow leaves. This butterfly likes woodland glades and narrow laneways, aswell as gardens.

Holly Blue butterfly - you can tell this one is female by the narrow black margins on the outer edges of the forewings: males have much thicker markings, effectively black patches.

If you are very lucky you might even be fortunate enough to see a mating pair. Mating is a quiet and symmetrical affair. The lovers rest, joined by their abdomens, but facing in completely opposite directions. They only move to angle their wings in the sun.

A mating pair of Holly Blues. Behind them is a dangerous-looking, but harmless and extremely handsome Syrphus hoverfly.

However, the sunlit leaves are not necessarily safe places. Predatory invertebrates brazenly wait, motionless in the undergrowth, for unwitting visitors to arrive to provide them with lunch. Crab spiders wait on the leaves, and will soon be hiding among the blossoms.

Flower Crab Spider (Misumena vatia), waiting for prey. Crab Spiders get their names from their habit of grasping prey with their two long pairs of forelegs, while balancing on their two shorter pairs of hind legs, as this one was doing.

However, many small creatures are fortunate enough not to hide on leaves. Your best chance of seeing the Early Thorn moth (Selenia dentaria) is now in April, usually perched on timber door or window frames, and garden sheds. The first generation male, pictured, is perfectly coloured to match dark timber, and dry leaves in the hedgerows.

A male Early Thorn moth perched on a door frame.

Sighting the first Swallow of the year

On Monday 28 March my brother Trevor and I paid a visit to the East Coast Nature Reserve. No sooner had we arrived than he spotted an unfortunate moth attempting to tread water in a slow moving area of river by the entrance. I climbed over the fence, and found a stick to fish the moth out with. This was a serious feat of derring-do, because if I’d fallen in I would have been wet to the knees. It was a Hebrew Character moth – Orthosia gothica – and I left it on some warm stones to dry off.

Hebrew Character

We spoke to the warden and project manager, Jerry Wray. Jerry was very busy, but took time out to tell me of some Garganey ducks that had arrived, and to lament the absence of the Stonechats, which seem to have been forced into a migration, or killed, by the severe winter. Only time will tell.

Jerry Wray on his East Coast Nature Reserve

As we sat in the main hide looking out for the Garganeys, on the ponds and lake of the reserve, Jerry suddenly shouted “There’s a Swallow!” and a single bird zoomed past the windows and began dipping in the lake for water. “That’s the first one I’ve seen this year! Have you seen many?” I asked. “No, That’s my first one aswell.”
That made the event even more special.

First Swallow of the year

Unfortunately I wasn’t quick enough to get a shot with my camera, but my brother Trevor managed to snap the bird. Not perfect, but pretty good for an unexpected appearance that didn’t last very long. And then the Swallow was gone. Later Jerry saw an entire flock of Swallows, which then followed the shore and astounded onlookers birdwatching at the Kilcoole Reserve to the north.

As Jerry headed back to work, Trevor and I decided to examine the reedbeds and see if there were any new developments. On the boardwalk we found two very interesting insects. The first was a brightly-coloured species of Rove Beetle, known only by its scientific name of Paederus riparius. Bright colours warn of noxious chemical spray from the rear-end. This lovely beetle normally patrols sandy areas, hunting fro smaller insects. It is only about 1cm long, at most, and very narrow.

Rove Beetle (Paederus riparius)

But our most exciting discovery was yet to come: in the form of a big, finger-length and brightly-coloured furry caterpillar. The combination of fu and bright colours usually denotes hairs that are toxic, so you must always handle caterpillars with great care. Some people are more allergic than others. Trevor recognised the caterpillar for what it was before I did – that of the Drinker moth, Euthrix potatoria. The caterpillar feeds on reeds and many other kinds of grasses, and contributes to the common name of this species because it is said to very actively drink from dewdrops. As you can see from the photograph, it was a very handsme caterpillar. The fire-red plume is over the head. It is very hard to tell one end from the other, except when its moving.

 

Drinker Moth caterpillar

Soon this big caterpillar will pupate, and then emerge as a magnificently camouflaged dead leaf-mimicking moth in July.

It was a good day’s hunting!