Wildlife
Geese
Greenland White-fronted Geese are the most numerous and important goose species on the reserve. They were first recorded in the area around 1910 and numbers built up to several thousand in the 1940s. Numbers fell by the 1970s to around 5,000 birds but increased protection resulted in an increase to up to 10,000; on
e third of the world’s population. Since 1999 there has been a slight decrease, accompanied by smaller broods of young birds. The decline may be due to climate change in Greenland; displacement from nesting sites by Canada Geese and pressures on migration routes.
Over 2,000 Pale-bellied Brent Geese, which breed in arctic Canada, also use the reserve in winter. Other goose species on the reserve include small numbers European White-fronted Geese, Barnacle Geese, Pink-footed Geese and Snow Geese. Lesser White-fronted Geese, Red-breasted Geese and Greylag Geese also visit in small numbers. In the first half of the twentieth century Greylags were the main goose species in the area.
Greenland White-fronted Geese have wintered in large numbers in Co. Wexford only since the 1940s.
To learn more about the Greenland White-fronted Geese click here
Swans
Mute Swans are present throughout the year with a peak in summer with a summer moulting flock of up to 240.
Up to 600 Whooper Swans from Iceland winter in the Reserve. Bewick’s Swans also winter in the area with recent maximum number of about 80.
Ducks
The common wintering duck species are Mallard, Wigeon, Teal, Tufted Duck and Pochard with smaller numbers of Shelduck, Goldeneye, Red-breasted Merganser, Shoveler, Gadwall, Scaup and Pintail. Rarer duck species visit occasionally and 31 species of duck have been recorded.
Waders
In Wexford Harbour and Slobs as many as 42 wader species have been recorded including some North American vagrant species.
On the reserve itself the main species are Lapwing, Golden Plover, Curlew, and Black-tailed Godwit, with smaller numbers of Redshank,Ruff, Oystercatcher, Dunlin, Spotted Redshank and Greenshank. Rarer waders occur in tiny numbers mainly on migration between April and June and from late June the first birds return from the north and passage continues until October.
Other Birds
Great-crested Grebe, Little Grebe, Moorhen, Coot, Grey Heron and Little Egret all nest in or near the Reserve and can be seen through the summer. Locally nesting non-waterfowl species include Long-eared Owl, Cuckoo, Raven, Skylark, Meadow Pipit, Stonechat, Reed Bunting and Sedge Warbler. Rarer species breeding locally include the Reed 
Warbler and the Tree Sparrow for which many nest-boxes have been installed on the reserve and nearby. Five tern species can be seen from the shore in Summer, including Little, Common, Arctic, Sandwich and Roseate Terns, all of which breed in Co. Wexford.
Large numbers of common farmland birds can be seen all-year round including Starlings, Rooks, Jackdaws alongside Common, Black-headed, Lesser Black-backed and Herring Gulls. Yellowhammers, now becoming scarce in Ireland, are present in winter. Birds of Prey in the area include locally breeding Kestrels, Sparrowhawks and Peregrine Falcons; these are joined in winter by Hen Harriers, Merlins and Short-eared Owls. In winter the Harbour shelters Great Northern and Red-throated Divers and Slavonian and Black-necked Grebes.
Mammals
The North Slob is a hare reserve, protecting a fluctuating population of Irish Hares, which belong to a distinctive race of the European Mountain Hare. Unlike other Mountain Hares they rarely turn white in winter, remaining a 
warm russet brown with white ear-fringes and pale eye-rings. They differ from the common Brown Hares of Europe in having shorter ears and being a little smaller and more compact.
Foxes and Badgers are common in the area along with Rabbit, Irish Stoat, Brown Rat, House Mouse, Pygmy Shrew, Otter, American Mink and Red Squirrel.
Five bat species have been recorded locally: Common Pipistrelle, Soprano Pipistrelle, Daubenton’s, Longeared and Leisler’s Bats. Hundreds of seals are often to be seen on sandbanks at the mouth of Wexford Harbour. Most are Grey Seals but a few Common (Harbour) Seals are often present.