Fauna

As the island warms, new arrivals from the south will offer, at least initially, some colourful and welcome additions to our wildlife. From a start in the sheltered estuaries of County Cork, the snow-white little egret from the Mediterranean has been steadily colonising our coastal wetlands, appearing even at the windy lagoons in the west of Ireland. Perhaps a score of new birds will breed in Ireland this century: the cattle egret and hobby are just two in early prospect.

Comma Butterfly
©Michael Viney

Among insects, the big and beautiful blue emperor dragonfly of Europe has begun to breed at lakes in Wexford in the south-east of Ireland, and the once-rare comma butterfly at the coast of the same county. The red admiral’s start on overwintering in Ireland could be followed by other migrants from the south. The great invasion of Ireland and Britain, in 2009, by millions of painted lady butterflies was caused by exceptional breeding in North Africa, and such events, too may have their origins in climate change. Among native insects, the brimstone butterfly and flame carpet moth are among the lepidoptera that are not only appearing earlier in spring but flying for longer in the season.

Bee colleting nectar

Bee collecting nectar.

Copyright Mike Brown

Bee colleting nectar
Copyright Mike Brown

Bee colleting nectar

Bee collecting nectar.

Copyright Mike Brown

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The annual migrations of flying insects often go unnoticed – those of some dragonflies and tiny hoverflies, for example – and rising sea-surface temperatures will help to increase this oceanic traffic. Among those arriving in Ireland, from the UK or by more direct flight from Europe, and colonising as the island warms, will be new wasps, bees, flies, beetles and moths. The species most likely to succeed in Ireland, and most rapidly, will be the generalists, adapted to the widest range of habitats, but others could aim for particular food. One moth caterpillar, for example, already widespread in Europe and Britain, destroys the leaves of the horse chestnut tree. Another fast-spreading predator, an Asian hornet, feeds on honeybees.

Immigrants like these will be extremely unwelcome as predators on vulnerable native species, as invasive pests of farming or forestry, or even as threats to human health (such as new mosquitoes capable of carrying viral diseases). Of course, they may not arrive under their own power or as a direct result of climate change, but as accidental introductions, encouraged to spread by the new warmth.