On a summer’s day the spot is idyllic. Ancient English woodland tumbles towards the broad river valley. The birds sing, the squirrels scurry.

Then suddenly the mood changes as a bear ambles mightily into sight among the oak trees. Another clambers up a towering ash and seems to take in the view down to the River Severn and and across towards the Forest of Dean.

Soon these Eurasian brown bears will be joined by a pack of Eurasian grey wolves and the two species will coexist – hopefully peacefully – in this corner of northern Europe for the first time in more than 1,000 years.

This is not an ambitious rewilding scheme but a project run by the Bristol Zoological Society to offer a glimpse into what ancient British woodland was like before humans cleared the forests to make room for homes and farms and exterminated some of the spectacular creatures that lived there.

The sight of bears and wolves together in one large enclosure will thrill visitors to Bear Wood within Bristol zoo’s Wild Place project but it is also designed to be thought-provoking – why did our ancestors think it acceptable to wipe out the bear and wolf and could we live with them again in the future?

Facebook Twitter Pinterest Eurasian grey wolves were hunted to extinction in Britain by the 16th or 17th century. Photograph: Alamy

Dr Christoph Schwitzer, the chief zoological officer, is pleased that even before next week’s public opening, Bear Wood is provoking such debate. The zoo is proud of its conservation projects that range from trying to bolster gorilla populations in central Africa to reintroducing white-clawed crayfish to the UK.

Schwitzer believes there is also a good argument for reintroducing larger creatures such as lynx to remote areas such as the Scottish highlands. “That may be worth trying. A population of 300 or 400 lynx might be viable,” he said.

But bears and wolves in England? “That’s a lot more tricky. There are a lot of factors you need to consider, the first being that we are a heavily populated country.” And human behaviour has not changed over the centuries. “People would still go out and kill them,” he said.

The opinion is not just theoretical. When a bear nicknamed Bruno wandered into German in 2006 he lasted only seven weeks before being shot by hunters. “People were so scared of it; they couldn’t live with it,” said Schwitzer.

All of which makes Bear Wood a bittersweet sort of place.

Facebook Twitter Pinterest A wolverine at Whipsnade zoo. The animal, a member of the mustelid family, will be part of the Bristol exhibit along with lynx. Photograph: Courtesy of ZSL Whipsnade Zoo

As well as wolves and bears, wolverines and lynx are to be found in Bear Wood. They are in separate enclosures so will not come face to face with the larger animals, though they will smell and hear them.

The wolverine is a member of the mustelid family that includes badgers, weasels and otters. It too once roamed British woodland before disappearing, presumably hunted for its fur and meat. A handful of wolverine bones have been found in Britain, more than half of them in south-west England and south Wales.

Lynx vanished after the wolverine as woodland was chopped down, and next it was the turn of the bear to disappear. Quite when native British bears became extinct is not known. Bears were a familiar sight in Roman and medieval times but they may have been imported.

Of the four Bear Wood creatures, only the wolf was left by 1086 and a mere 15% of Britain was covered by woods. Wolves were hunted to extinction by the 16th or 17th century and now only 2% of Britain is covered in ancient woodland.

Introducing the bears and wolves to each other will be a delicate process. “You have to observe rules,” said Schwitzer. “You can’t just throw them in together.”

At first the five wolves will be brought into a separate enclosure next to the large one where the four bears are currently roaming so the two species can get used to one another.

Facebook Twitter Pinterest Two of the four bears in Bear Wood. Photograph: Andre Pattenden/Bristol zoo

When the keepers judge the time is right the wolves will be allowed into the joint enclosure, though they will be able to retreat without the bears following them if they feel the need.

“Conflict arises around prey or offspring,” said Schwitzer. So they will feed separately. The three male bears are to be castrated and the five wolves are all males so there will be no breeding and so no young to fight over.

The fact that the bears and wolves have a 10,000 sq metre wooded paddock to share should help. They can keep away from each other if they want and interact if the mood takes them.

Scientists will also be interested to find out what impact they have on the woodland. “We’ll be able to see how they change the flora and fauna,” said Schwitzer. The squirrels are likely to flee and the bears may clear vegetation, allowing more light-loving plants into the woods. Different invertebrates may move in.

It will also be interesting to see how the bears and wolves operate as summer gives way to autumn and winter. It is not clear whether the bears will dig themselves into a den and hibernate.

Across the Severn wild boar live wild in the Forest of Dean after accidental and deliberate releases from farms, and a year ago beavers were released into a large pen in the forest as part of a project to alleviate flooding. Wild beavers have also returned to a river in Devon. They are unlikely to be joined any time soon by bears or wolves.