The Park is situated at the confluence of Morthen and Ulley Brooks, where the construction of the reservoir was completed in 1874. This created an area containing a broad diversity of habitats, ranging from the reservoir itself with its aquatic margins to grasslands below the dam and steep wooded hillsides bordering the streams. A pond, created in 2009 to replace the old filter-beds, augments these habitats and provides a useful facility for school pond-dipping groups. Each habitat supports a wide and differing variety of plants and animals, which make the Park a haven for amateur naturalists.
Mammals
Grey Squirrels can be seen around the park and although declining, Brown Hares can sometimes be spotted in adjacent fields. Various species of mice and voles occur, which in turn provide prey for Stoats and Weasels.
Reptiles and Amphibians
A notable species within the park are Grass Snakes which, in warm weather, visitors may be lucky enough to see sunning themselves or swimming in the reservoir or the pond. Common Frogs and Toads also occur in good numbers.
Fish
The reservoir holds good stocks of coarse fish, making the Park a popular venue for local anglers. The pond and streams also hold good numbers of Sticklebacks.
Birds
Well over 120 species of bird have been recorded within the Park. Commoner species such as finches are augmented in winter by several types of wildfowl and in summer by migrant warblers. Buzzards can regularly seen soaring overhead and Mute Swans and Great Crested Grebe regularly nest. Occasionally, rarer species turn up. Both Red-necked Grebe and Slavonian Grebe have been recorded.
Insects
A huge variety of insects can be seen in all the suitable habitats. 20 species of butterfly have been recorded, the most notable being White-letter Hairstreaks which live in the Wych Elms adjacent to Ulley Holt. Many moths are also to be found although, apart from a few day flying species, a light trap is needed to record these nocturnal insects. A trapping session in July 2008 turned up a Buff Footman which was the first ever record for that species in the Sheffield/Rotherham area. 9 dragonflies and 5 damselflies occur around the water margins during the summer months and close views can be obtained if approached with care. Beetles, hoverflies, bees and many other types of insect add to the enormous scope for amateur entomologists.
Plants
UlleyCountryPark is situated on sand stone above coal seams, which were mined from Treeton Colliery, and the underlying geology and the effect of the reservoir have created several ecological habitats considered to be of National Conservation importance. These include wetlands and swamp, lowland neutral grassland, and patches of lowland acid grassland and heathland, each of which supports different species of wild flowers and grasses.
Wetlands and Swamp.
Found at the end of the Ulley Arm at Ulley Holt and the end of the Morthen Arm, are wetland species such as Bulrush (Typha latifolia), Celery–leaved Buttercup, Water Forget-me-not, Reed Canary-grass, Soft Rush and Jointed Rush along with Meadow Sweet, Wild Angelica, Brooklime, and Great Willowherb. Golden Saxifrage (opposite leaved species) is found beside the Ulley and Morthen Brooks.
Willow carr can be found in the wetlands containing Crack, Grey, and Goat Willow often used by the Great Crested Grebe, Swan and Coot as nesting sites. Alder grows round the edge of the reservoir, in the drainage ditches and beside the Ulley and MorthenBrooks.
Lowland Neutral Grassland
In the Ulley Arm, part of Ulley Holt, the northern side of the Morthen Arm and the west side of the Dam wall, Birdsfoot Trefoil, Bush Vetch, Tufted Vetch, Red and White Clover, Common and Lesser Knapweed, Creeping and Spear Thistle, Ox-eye Daisy, Rosebay Willowherb, Field Scabious, Common Poppy, Cow Parsley and Creeping Buttercup can all be found along with many other species.
In the woodland along the Ulley Arm, at the end of the Morthen Arm and below the Dam Wall, Silver Birch, Oak, Rowan and Alder, Sycamore, Willow, Hazel, Ash, Hawthorn, Blackthorn and Elder all grow. The woodland floor supports Bluebell, Wood Anemone, Wood Sorrel, Lesser Celandine, Ground Ivy, Common Dog Violet, Red Campion and Greater Stitchwort.
Lowland Dry Acid Grassland and Heathland.
There is a patch of Heather (Calluna vulgaris) with Heath Bedstraw, Tormentil, Sheep’s Sorrel, Wavy Hair-grass and Sheep’s-Fescue on the west side of the SailingTower and a similar larger patch of Heather below the new Spillway on the hillside above the Environmental Resource Centre. The large bank of dry acid grassland, which is to the south of the Morthen Arm, is known as the Gorse Bank. This is covered with a large patch of Gorse, with Bracken and in the grassy clearings Tormentil, Heath Bedstraw, Wavy Hair-grass and Foxgloves can be found. Small Oak trees, Rowan, Ash, Silver Birch and Rhododendron grow there.
Fungi
In Autumn Fly Agaric toadstools with their bright red caps covered with white scales are found growing beside the path under the Silver Birch trees.
In November 2011 forty different species of Fungi were identified between the Park entrance and the Sailing Tower.
Note to visitors
Visitors walking round the Park will find five interpretation boards that illustrate various species that may be seen and which hopefully will aid in identification. This web-site also contains a gallery of wildlife photographs – all taken within the Park, again showing the wide diversity of flora and fauna to be found.
