We've just endured a really tough winter but records suggest that Spring is on average beginning much earlier. Lindsey Chapman investigates how shifting seasons are affecting our wildlife.

Bumblebees in January, daffodils blooming early, 'thuggish-vegetation' thriving as a result of mild winters and damp summers: the seasons appear to be blurring and wildlife is becoming confused. The overall impact is 'quite staggering' according to Matthew Oates, butterfly expert from the National Trust.

In this week's Costing The Earth, Lindsey Chapman meets Matthew as he takes stock of our shifting seasons. He explains how early spring can throw several species out of kilter, creating a mismatch between wildlife and their prey. And what happens when- like this year- we get an icy snap in the middle of a mild spell?

Lindsey meets the scientists studying the mechanisms driving the UK's climate, phenologists who have been studying the link between seasons and species and the naturalists who are spotting new species turning up on our doorstep.

Producer: Martin Poyntz-Roberts.