Nature plays tricks with year of strange weather upheaval
Published 27/12/2011 | 05:00
THE topsy-turvy weather of 2011 had a roller-coaster effect on the natural world, new records show.
The freezing winter, the hot spring, the cool summer and the near-record warm autumn had striking but very different effects on birds, mammals, insects and plants, at first devastating populations, then allowing them to rebuild at record rates, and in cases such as butterflies, letting them linger far longer than normal.
Small birds in particular suffered badly from the icy start of 2011, the coldest winter for 20 years -- the smaller you are, the more quickly you lose heat and energy, and food sources such as worms are impossible to access in frozen ground.
Tiny wrens plunged by a massive 31pc according to the British Trust of Ornithology and robins by 30pc, while greenfinches and chaffinches also suffered big drops, of 24 and 15pc respectively. Yet when spring came, unseasonably warm, unseasonably early, many of these species were able to build their numbers back up rapidly, and in some cases had breeding seasons which in terms of productivity were also records.
Some larger birds, especially birds of prey, also did very well, with kestrels, barn owls and tawny owls all producing broods of chicks which were larger than normal as the small mammals on which they feed were plentiful last spring, protected by a blanket of snow through the winter. "Then the warm, dry spring weather provided perfect hunting conditions," the Trust said.
Butterflies and moths were "bamboozled" by the weather, according to the charity Butterfly Conservation, with many species appearing much earlier and later than in a typical year.
The hot, dry spring combined with the warm autumn saw butterflies on the wing from early March to mid-December. It also saw a huge influx of migrant moths from southern Europe with exotic species such as the crimson speckled recorded into October. The warm weather of Christmas week has also been tricking flowers into blooming early, according to observers.