Birds come down to earth in the year of the slug

A record wet April was followed by the wettest summer since 1912, creating soggy conditions ideal for molluscs

Some British birds and butterflies had disastrous breeding seasons in the sodden weather of 2012, it is now clear, while other wildlife also struggled in the wettest summer for a century.

Breeding productivity tumbled in birds such as the chaffinch, and butterflies such as the common blue, as nests were washed out and insects were unable to fly to find mates and lay their eggs.

"Virtually everything was hit," said Paul Stancliffe of the British Trust for Ornithology, while Richard Fox of Butterfly Conservation said that, for butterflies and moths, "it was an awful year".

In fact, the wildlife year began promisingly with one of the warmest and driest Marches on record, which meant that early-breeding birds, residents such as the long-tailed tit, did comparatively well. It came at the end of a second successive dry winter, amid fears of a major drought.

But no sooner had water restrictions been imposed in southern England in early April than the heavens opened and a record wet April followed, which was followed in turn by a record wet June, and then the wettest summer as a whole since 1912. The big winner amid the soggy conditions were slugs – including the giant Spanish super slug which was reported to be invading gardens.

But the rain meant the number of fledglings birds could produce dropped alarmingly in many cases: chaffinch chicks were nearly 60 per cent down on their average, according to the BTO, with reed warbler productivity more than 35 per cent down, and large drops in other warbler species such as blackcap, whitethroat and chiffchaff.

Among butterflies, common blues had a disastrous breeding season, and there were poor performances from the holly blue and the whites. But many plants, such as wild orchids, did well.

"In general, plants and slugs were the big winners and insects the losers," said Matthew Oates, resident naturalist at the National Trust. "This has been a highly polarised year, with wildlife in the places we look after doing either remarkably well or incredibly badly." Orchids had a fantastic year almost everywhere.

But, according to the Trust, the April downpours had a detrimental impact on fruit harvests in the autumn as the spring rains washed away the blossom, resulting in a very bad year for English apples, and fruits and berries such as sloes and holly berries.

It was a also a bad summer for the insect pollinators: bees and hoverflies suffered setbacks, although the good news for picnickers this year was that there were very few wasps. In its end-of-year assessment, the Trust says: "Mammals have had a mixed year, with bats having an especially difficult time. Water mammals have also suffered greatly, with water vole holes being washed away in the floods. Animal sanctuaries are now inundated with underfed hedgehogs, and dormice also had a poor breeding season."

Flora and fauna: 2012's ups and downs

January Earliest recorded flowering magnolia appears in Lanhydrock, Cornwall, on New Year's Day; snowdrops and crocuses also flower earlier than normal in the mild winter weather.

February Survey of 50 National Trust gardens on Valentine's Day finds a 19 per cent increase in flowers in bloom compared to 2011; rooks begin building nests earlier than typical.

March Drought orders put in place across swathes of England after a second successive dry March; supposedly extinct large tortoiseshell butterflies, right, seen on the Isle of Wight, but the unseasonally warm weather hits badgers, as they struggle to find food in dry soil.

April Snow and the wettest April ever recorded fail to shift widespread hosepipe bans; heavy rains means kingfisher holes and water-vole burrows are drowned by floods; a short bluebell season adds a splash of colour.

May Continued wet weather leads to the widespread failure of spring fruit blossom; cuckoos fail to breed at Wicken Fen for the first time; insect populations partially recover towards the end of the month; a very rare cream-coloured courser is spotted in Herefordshire – the twitch of the year

June Orchids flourish with spectacular displays at Blakeney on the Norfolk coast and Stackpole Warren in Pembrokeshire, and hundreds of fly orchids on Dunstable Downs; large blue butterflies emerge in good numbers, laying a record number of eggs at the National Trust's Collard Hill in Somerset; breeding success for sandwich terns and little terns at Blakeney Point.

July Over 150 per cent of normal rainfall – the arrival of Spanish super-killer slugs makes the headlines; a good year too for dragonflies, with 22 species recorded at Scotney Castle, Kent.

August A terrible summer for bee-keepers with bees at the National Trust's Attingham Park, West Midlands, having to be fed; wasp numbers are also very low and swifts depart after a very poor breeding season.

September Improving weather fails to boost apple crops, with a 90 per cent drop in Dorset affecting cider production; signs of a second-spring effect with the bogbean flowering at Malham in the Yorkshire Dales (which normally flowers in April).

October Massive landfall of thrushes from Scandinavia at Blakeney Point, Orford Ness and Farne Isles on the east coast; pheasant feeder bins emptying much faster than usual, due to unusually hungry birds, mice and other mammals

November More floods strike the South-west and then the north of England; there is a reasonably good show of waxcap fungi in Lake District and Llanerchaeron, Ceredigion; seal pups break the 1,000-barrier at Farne Isles and Blakeney Point

December Consequences of a wet spring are felt with low numbers of holly berries; there is an invasion of the normally rare migrant bird, the waxwing.