Details of the Hertfordshire and Middlesex Wildlife Trust's 45 reserves. Herts and Middlesex Wildlife Trust manages more than forty reserves across two counties, including some of the best wildlife sites in the UK. These nature reserves cover the wonderful diversity of our landscape, from woodland to grassland, wetland, and heathland. Each reserve is home to a fantastic array of wildlife, supporting a range of species such as plants, mammal, amphibians, reptiles, invertebrate and birds.