Staff at Northumberland Wildlife Trust's Gosforth headquarters, in the grounds of St Nicholas Hospital in Newcastle, arrived at work to find two of its fleet vehicles vandalised.

The VW Caddy van, used for transporting equipment between more than 60 nature reserves and by the Wild City to transport display equipment to schools, had its rear windows smashed.

The charity's 12-year-old Land Rover also had all its windows and windscreen smashed, and its wing mirrors pulled, rendering it undriveable.

The Land Rover, which transports tractors and other heavy equipment around the region, is used by the charity's estates officers and volunteers, who will now face downtime until it is repaired.

The vehicle is also important for meadow management, such as towing hay-making equipment, which has now had to stop.

Geoff Dobbins, Northumberland Wildlife Trust estates officer, said: "The work on our reserves is seasonal, dictated not only by the weather, but what is happening with the plants and animals.

"This mindless vandalism really upsets the timetable of work scheduled for our reserves and we will spend the next few weeks playing catch up when it is so unnecessary."

The wildlife charity has also suffered vandalism on its other reserves throughout Newcastle, Northumberland, and North Tyneside.

At Howdon reserve in North Tyneside, security fencing was cut last week, which is a regular occurrence.

At Whitelee Moor reserve, off-road bikes driven across the blanket bog have damaged the peat, which is essential for carbon storage.

Big Waters reserve experiences bouts of vandalism, particularly to the wildlife watching hides.

At Holywell Pond reserve, the public hide is subject to smashed glass and litter, believed to be left by people drinking alcohol there on the weekend, and which is cleared away by the Holywell Warden Group.

Briarwood Banks reserve, despite being in a remote area of Northumberland, usually has several fires each summer, along with littering, burnt-out tents, and random tree felling.

Close House and Priestclose Wood reserve, also in a remote area of Northumberland, have both suffered from fires, damage to their public information panels, and damage to their fences.

At Prestwick Carr, near Ponteland, information boards have recently been smashed.