Signs of spring

Traditionally, swallows are first sighted at the start of April. This year the first was seen in mid February Photograph: Franco J F Bonnard/Corbis

The traditional time for frogspawn is March but in the south-west of England frogs were spawning in December Photograph: Martin B Withers/Frank Lane Picture Agency/Corbis

Daffodils, once regarded as coinciding with St David's Day (March 1), have been in flower since January. Daffodils will flower early if it is warm in late winter/early spring Photograph: Sean Smith/Guardian

Unlike daffodils, snowdrops tend to flower earlier if the previous autumn was cold Photograph: Herbert Kehrer/zefa/Corbis

The Woodland Trust's Nature's Calendar is full of reports of early catkin sightings Photograph: Philip and Karen Smith/Corbis

Lesser celandines have been flowering since January - much earlier than normal Photograph: Niall Benvie/Corbis

A bluebell wood in Monzievaird. Blubells have been spotted since early February. Their traditional flowering time is the beginning of May Photograph: Kathy Collins/Getty

Insect sightings have been unpredictable for several years. Ladybirds, traditionally unsighted until March, have been seen since the beginning of the year Photograph: Dan Chung/Guardian

A blue tit feeding its young. Blue tits were seen nesting in mid January. Their traditional nesting period is March to May Photograph: George McCarthy/Corbis