AS far back as the 13th century, Chirk Castle has been renowned for its wildlife. There has been a hunting forest here as long as there has been a castle, including a vast medieval deer park. At its height in the 17th century the estate was a sprawling 10,000 acres and boasted a 500-strong deer herd.

These days the Chirk estate is especially rich in biodiversity, as recognised with the designation of its Site of Special Scientific Interest (SSSI) in 2011.

There are more than 650 ‘veteran’ trees on the estate, many dating back to an extensive planting scheme by landscape gardener William Emes in the 18th century.

The natural features of these ancient trees mean they are ecosystems in their own right, supporting species of lichens, liverworts and mosses, providing roosting and breeding sites for bat species, as well as nest sites for bird species, including treecreeper and great spotted woodpecker.

A recent survey of the parkland surrounding Chirk Castle showed that the Index of Ecological Continuity (IEC) value at Chirk has now reached 75 - an increase of about 10 per cent on 1996, and a score of high GB significance, placing the parkland at Chirk Castle among the top 25 sites in Britain and the richest in Wales.

The Site Quality Index (SQI) has changed from 368 in 1996 to 439 in 2018, an increase of nearly 20 per cent.

Head ranger, Carl Green, said: “The report has looked especially at the amount of invertebrates we have living here at the estate. They mainly live in dead and decaying wood and the survey found that certain species are only found here or a few other sites.

“The fact that we have lots of ancient trees and decaying wood and the overall history of the site as a hunting park and without that longevity of tree cover you just don’t get these species.”

As Carl says, the site is of particular interest for the important invertebrate species that the veteran trees support.

More than 313 different species of wood-decay invertebrate are now known in the parkland, a remarkable total for a single site. These include 207 species of beetle, 82 of fly, one snake fly, two bugs, 12 bees and wasps, one moth, six spiders and two millipedes.

As well as the invertebrates, the standing and fallen deadwood provides habitat for species of fungi with both in turn, providing a vital food source for many species of bird and small mammal.

Seven different bat species have been recorded on the estate, with the most notable being the rare, lesser horseshoe bat.

The estate woodlands and close proximity to the River Ceiriog provides the perfect habitat for foraging for insects, while the roof spaces in the castle buildings act as an important site for summer roosts.

The most recent survey has shown that this population is steadily increasing.

Today, the woodland is 70 per cent oak trees, including some amazing and unique veteran trees many hundreds of years old.

The estate is part of the Veteran Tree Initiative, helping to conserve veteran trees. Part of this is a 25-year tree planting scheme based on Emes’ designs, where 1,500 trees will be planted, replacing those trees which have been lost.

The estate is also located within the Clwydian Range and Dee Valley Area of Outstanding Natural Beauty (AONB) and is managed by a team of just three National Trust rangers, and a dedicated group of volunteers, who not only maintain the fences and landscape, plant and manage the trees, and protect the wildlife, but they also work with schools and local community groups to share their knowledge.

“Rather than clear fallen trees and cut them up into firewood or logs we leave them in situ, meaning the insects have a home to go to and the right environment to continue for the next generation,” explains Carl. “They are at the bottom of the food chain and without them the bird species wouldn’t thrive as well.

“We’re very keen to tell people to look after the Amazonian rain forest but if they should also look at what’s on their own doorstep.

“It’s only a very small environment and there are not many of these medieval hunting parks left, so we have to look after them. Once we lose them, we’ll never get them back.”

Chirk is still a working estate, with tennants farming the land.

The Myddelton family still keep livestock on the estate, including historic breeds such as White Park cattle, English Longhorn cattle and Welsh Black sheep.

Wild ponies are used for conservation grazing in the woodlands to help reduce the bracken cover and promote natural regeneration of the trees.

Numbers of grazing sheep on the front park of the estate have been reduced in order to assist grassland fungi populations.

“My job is to look after the estate and it can range from anything to everything,” laughs Carl, who has worked the estate for 37 years. “Today I’ve been digging holes for tree planting and putting tree guards up and we have a group of volunteers coming to help me do the same.

“It’s all about making sure the environment is suitable for wildlife. The estate is a great place to see a range of bird species all year round and spring brings a large number of migrant species, with blackcap, chiffchaff, pied flycatcher and redstart all breeding within the woodlands.

“It can be pretty tough, especially when they’re predicting snow but we have 476 acres here and I like to think I know the estate like the back of my hand.

“It’s been here for over 700 years and it’s good to be part of that history.”