Colin Williams of the wildlife trust gets set to welcome insects and other species

Every spring I wonder when I’m going to see the first butterfly of the year. Will it be a red admiral fluttering among the cobwebs in a garden shed, or a small tortoiseshell emerging from dense ivy where it’s been hibernating all winter?

This year it was the beautiful brimstone butterfly, with its eye-catching yellow wings appearing to reflect the warm sunshine as it flitted along the open ride at Warburg Nature Reserve.

Several different butterflies, including peacock and red admiral, will spend the winter in a dormant state, hibernating until the temperature rises above 11C.

This is one of the magical aspects about nature. Insects can detect and respond to warmth even though they are asleep, then wake up, stretch their wings and fly off in search of nectar to replenish their energy resources and get ready for the spring season of breeding.

I hope we don’t get a cold snap later this month. This could be disastrous for butterflies and other insects, such as solitary bees, that have been enticed to emerge from hibernation by the early spring sun.

A week or two of sharp frosts can damage the flowering plants that provide vital nectar for insects. If butterflies have to go back into hibernation now, they will have used up vital energy without being able to replenish their resources.

Good sites for spotting the early risers include the Cothill Fen reserves such as Dry Sandford Pit, near Abingdon; the sunny slopes of BBOWT’s Chilterns reserves of Oakley Hill and Chinnor Hill; and the open rides in Warburg Nature Reserve. In woodlands, hedgerows and hollow trees other creatures are stirring as the sun’s rays warm up the air and encourage hibernating animals to wake up.

Badgers will start clearing out their winter bedding, scraping out old grass, twigs and moss to be scattered outside their setts as the animals get ready for spring. Fresh bedding will be dragged into the sett as the females get ready for the birth of their cubs.

Every February, the Biodiversity Team at BBOWT does a similar spring-cleaning task for hazel dormice at Chinnor Hill. We repair any damage and remove any old nests from the dormice boxes we have previously put up so they are ready for dormice to nest in.

Hazel dormice spend the winter curled up tightly in a tiny ball of woven grass and small twigs covered in moss at the foot of coppiced hazel trees, or deep in the bottom of hedgerows. Few people ever see these nests until the dormice have left them for their spring and summer locations up high among woodland trees.

The other name for this animal is common dormouse, which belies the fact that it isn’t really common at all. This is mainly because there are fewer woodlands in the countryside due to changes in land use.

Dormice need trees for their food as well as a place to live, starting with hawthorn flowers in April, then honeysuckle and occasionally the caterpillars of woodland butterflies, before the autumn harvest of hazel nuts. Dormice, and their nesting and breeding sites, are protected under Conservation of Habitats and Species Regulations 2010 and the Wildlife and Countryside Act 1981. Checking dormice boxes can only be done under licence from Natural England.

We start this in April to monitor the numbers of dormice and their litters. It’s much easier for us to lift the lids of the boxes than try to peer into a hole in a tree, but please don’t try this yourself.

Like dormice, bats hibernate through the winter in a state of torpor. Common pipistrelle bats can be found in lofts, old sheds and hollow trees, emerging when there are more insects about for them to eat, build up their depleted energy resources and breed.

CS Lewis Nature Reserve at Risinghurst will be a good spot to see bats emerging from the roost in the old bomb shelter.

To find out more about the emerging spring wildlife on BBOWT’s reserves log on to www.bbowt.org.uk