WILDLIFE Trust volunteers come from all walks of life and range in age from schoolchildren to the retired.

That said, John Zehetmayr is still a pretty unusual example. The warden of Lavernock Point nature reserve in Penarth is fast approaching his 85th birthday, but showing no signs of slowing down.

As well as helping to care for the 14.5 acre reserve, he also teaches skiing, and is looking forward to spending his next birthday in the Alps with his family.

"I've been a skiing instructor for over 20 years, and I teach at the ski school in Fairwater in Cardiff," he explained.

"I like to keep active."

During the past fortnight, however, John has been devoting a great deal of his energy to his other passion nature.

He and fellow warden Jeff Curtis, along with a team of eager volunteers, have been preparing the Lavernock Point reserve for its annual opening to the public.

Every year, volunteers lead guided walks around the coastal limestone grassland reserve managed by the Wildlife Trust of South and West Wales, and this Sunday, from 11am, they will be welcoming visitors and showing them just what makes the reserve so special.

"The reserve is a haven for wildlife, and part of it is classified as a Site of Special Scientific Interest (SSSI)," said John, who has been a warden for 30 years, since retiring as the senior officer in Wales with the Forestry Commission.

"My great passion is butterflies, and Lavernock Point is an excellent place to see them.

"My personal record is 16, and I'm hoping to beat that this weekend if the weather is good.

"Three years ago, some people recorded 17, so I'm keeping my fingers crossed.

"Visitors will almost certainly see the four browns the meadow brown, the ringlet, the speckled wood, and the gatekeeper and probably the lovely yellow brimstone, which should be hatching about now.

"Then, of course, there are all the migrants from the Mediterranean, like the red admiral and the painted lady.

"One of the most exciting things around at the moment, though, is the hummingbird hawkmoth, which is always lovely to see."

Lavernock Point comprises an inland unimproved meadow and a cliff-top field bearing a mosaic of fine, unimproved limestone grassland and scrub.

The area supports a rich variety of plants such as agrimony, dyer's greenweed, St John's wort, adder's-tongue fern, cowslip, and common twayblade, as well as early purple orchid, common spotted orchid, bee orchid, and greater butterfly orchid, which occur in glades in the scrub.

Keen birdwatchers regard it as an important site for the observation of bird migration.

Large numbers of yellow wagtails pass through in late summer, with many of the more unusual migrants such as firecrest, brambling, and large parties of redpolls using the scrub as a resting station.

Lavernock Point also has an important place in the history books, of course. In May 1897, Marconi made history by sending the first wireless signals across the water from Lavernock Point to Flat Holm island.

Keeping the reserve looking at its best is a round-the-year job, but John is fortunate that Penarth and the surrounding areas are home to an enthusiastic army of helpers.

"We were overwhelmed when we asked for help to tidy up the reserve in preparation for the open days," he said.

"We had 12 people there but the new mower we were using, thanks to the Heritage Lottery Fund, was working so fast they hardly had anything to do.

"I just hope none of them felt unused and that they come back another day there is always plenty of work to do!"

As well as hoping for a successful weekend, John is also keeping his fingers crossed for another forthcoming event.

The reserve has been entered for the Vale Biodiversity Award the competition launched last year by the Vale of Glamorgan Local Biodiversity Partnership to projects which promote biodiversity by creating, improving, or managing sites for wildlife.

"If we win that, I will be so pleased," John said.

"It will mean so much to so many people who have helped look after this very special reserve."

Lavernock Point is 8 km south of Cardiff and 6 km east of Barry. Access is from the B4267, via a minor road signposted Lavernock Point.

Vehicles can be parked before the entrance to the Marconi Club, and access on foot is by way of a public footpath.

Guided walks take place from 11am to 4pm this Sunday.

For more information, contact the Wildife Trust of South and West Wales on 01656 724100.