The unusually cold weather at the start of Spring 2013 means that some animals such as bats, great crested newt and reptiles may stay shut down longer and remain immobile to conserve energy.

Some bats are still in torpor, the state of deep sleep they adopt to survive the British winter.

The start of the survey window for great crested newt and reptiles will be delayed this year until the weather warms up somewhat, and may be delayed until April.