As you stroll through Warburg Nature Reserve, near Henley, this winter you may be surprised to find a few animals that are larger, furrier and woollier than you would normally expect to see.

Warburg is one of several reserves managed by the Berkshire, Buckinghamshire and Oxfordshire Wildlife Trust that are home to cattle, sheep and ponies — four-legged conservation workers creating the best habitats for plants and grasses to flourish.

BBOWT’s conservation grazing officer Louise King said: “Cattle are really good at browsing their way through brambles and other scrubby undergrowth.

“They’ll eat almost any vegetation that’s up to their head height. This keeps flower-rich grasslands open and prevents scrub from encroaching.

“Sheep and ponies nibble close to the ground and graze out the competitive species of grass that threaten to overwhelm the slower growing species such as finer grasses, wild thyme and orchids.”

BBOWT has livestock on half the Oxfordshire reserves.

Using small groups of sheep or cattle is a good way to manage the smaller reserves in winter, while larger groups graze Sites of Special Scientific Interest (SSSI) such as Hartslock, near Goring, and Iffley Meadows in Oxford. New Forest and Exmoor ponies are more suited to the wetter fenland conditions such as Parsonage Moor, near Cothill.

The trust’s conservation and biodiversity team has a management programme for each reserve which includes which animals are needed, how many and for how long.

Volunteers carry out annual wildlife surveys which are assessed by BBOWT staff who recommend the best grazing programme.

It could be intensive grazing with several animals for a few weeks, less intensive grazing with a few animals over several months, or even a combination to get the right habitats for particular species.

An example of this can be seen at Warburg where there are Jacob, Wiltshire Horn and Beulah Speckled Face sheep grazing in small fenced-off areas along the open rides.

They prefer rough grazing to lush grass, and, because they are not breeding, they only need to eat for themselves.

“This is relatively intensive grazing, so we move them along the rides every week or so,” added Louise.

“By the end of the winter they’ll have grazed all these open areas short enough to give a wonderful display of wildflowers in the spring and summer.”

In large fenced-off areas, four black Dexter cattle trample bracken and chew on brambles and thistles.

Like the sheep, these are hardy breeds that live outside all winter with natural shelter from the trees in bad weather.

Hay cut from fields elsewhere supplements winter grazing.

“We select our livestock carefully to suit the conditions on the reserves,” said Louise. “Some of the Dexters came from a herd on Hungerford Marsh where they’re used to eating scrubby herbage.

“This means their digestive system is adapted to this type of fodder. If we brought animals off rich pasture they wouldn’t be able to cope with the less nutritious vegetation.”

Volunteer stock watchers check the animals regularly and Louise visits them at least once a week.

“The stock watchers do a grand job. They’ve had training so they know what to look for and let me know if any animals are lame or need my attention,” added Louise.

The animals are checked regularly by the vet, vaccinated against Bluetongue, a disease spread by midges that only affects sheep and cattle, and given preventative treatments for flies.

Moving the animals frequently to new grazing reduces any worm problems.

Louise enjoys meeting visitors on the reserves and talking about the livestock.

“I always stop and have a chat with people, especially dog walkers.

“Some livestock are just as nervous of dogs as the wildlife is, which is why the trust asks people to keep dogs on leads on reserves at all times.

“Temporary signs are put up to let people know when the livestock are grazing on the reserves.”

Louise worked with sheep and cattle on a farm in Berkshire before she was bitten by the wildlife conservation bug.

“I’d become more interested in the wildlife than the farming, and took the opportunity to join BBOWT as a conservation trainee, which I did for a year, and that led to this job.

“Now I’m out and about with the animals, I see the most beautiful countryside and do my job all at the same time.”

l Visit www.bbowt.org.uk for information on getting involved in work parties on Oxfordshire reserves, becoming a volunteer stock watcher and finding out where to spot winter wildlife this weekend.