The Stour Estuary is a nature reserve

Nature reserve

A nature reserve is a protected area of importance for wildlife, flora, fauna or features of geological or other special interest, which is reserved and managed for conservation and to provide special opportunities for study or research...

 in Essex

Essex

Essex is a ceremonial and non-metropolitan county in the East region of England, and one of the home counties. It is located to the northeast of Greater London. It borders with Cambridgeshire and Suffolk to the north, Hertfordshire to the west, Kent to the South and London to the south west...

, England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

, east of Colchester on the estuary

Estuary

An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....

 of the River Stour

River Stour, Suffolk

The River Stour is a river in East Anglia, England. It is 76 km long and forms most of the county boundary between Suffolk to the north, and Essex to the south. It rises in eastern Cambridgeshire, passes to the east of Haverhill, through Cavendish, Sudbury and the Dedham Vale, and joins the...

, managed by the Royal Society for the Protection of Birds

Royal Society for the Protection of Birds

Bird Notes and News was first published in April 1903.The title changed to 'Bird Notes' in 1947. In the 1950s, there were four copies per year . Each volume covered two years, spread over three calendar years...

, (RSPB).

The reserve is unusual in that it consists of two divergent habitat

Habitat (ecology)

A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism...

 types: intertidal mudflats (fringed by saltmarsh and estuarine reeds), and 130 acres (0.5 km²) of deciduous woodland

Woodland

Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...

, mainly oak

Oak

An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...

 and coppiced sweet chestnut

Sweet Chestnut

Castanea sativa is a species of the flowering plant family Fagaceae, the tree and its edible seeds are referred to by several common names such Sweet Chestnut or Marron. Originally native to southeastern Europe and Asia Minor, it is now widely dispersed throughout Europe and parts of Asia, such as...

.

The estuary is important as a breeding, roosting and wintering site for many waterfowl

Waterfowl

Waterfowl are certain wildfowl of the order Anseriformes, especially members of the family Anatidae, which includes ducks, geese, and swans....

 and other bird

Bird

Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

s, including woodpecker

Woodpecker

Woodpeckers are near passerine birds of the order Piciformes. They are one subfamily in the family Picidae, which also includes the piculets and wrynecks. They are found worldwide and include about 180 species....

s, Nightingale

Nightingale

The Nightingale , also known as Rufous and Common Nightingale, is a small passerine bird that was formerly classed as a member of the thrush family Turdidae, but is now more generally considered to be an Old World flycatcher, Muscicapidae...

, Blackcap

Blackcap

The Blackcap is a common and widespread sylviid warbler which breeds throughout temperate Europe, western Asia and northwestern Africa, and winters from northwestern Europe south to tropical Africa...

, Whitethroat

Whitethroat

The Common Whitethroat, Sylvia communis, is a common and widespread typical warbler which breeds throughout Europe and across much of temperate western Asia. This small passerine bird is strongly migratory, and winters in tropical Africa, Arabia and Pakistan.This is one of several Sylvia species...

, Sedge Warbler

Sedge Warbler

The Sedge Warbler is an Old World warbler in the genus Acrocephalus. It is a medium-sized warbler with a brown, streaked back and wings and a distinct pale supercilium. Sedge Warblers are migratory, crossing the Sahara to get from their European and Asian breeding grounds to spend winter in Africa...

, Reed Warbler

Reed Warbler

The Eurasian Reed Warbler, or just Reed Warbler, Acrocephalus scirpaceus, is an Old World warbler in the genus Acrocephalus. It breeds across Europe into temperate western Asia. It is migratory, wintering in sub-Saharan Africa....

, European Wigeon, Common Shelduck

Common Shelduck

The Common Shelduck is a waterfowl species shelduck genus Tadorna. It is widespread and common in Eurasia, mainly breeding in temperate and wintering in subtropical regions; in winter, it can also be found in the Maghreb...

, Northern Pintail

Northern Pintail

The Pintail or Northern Pintail is a widely occurring duck which breeds in the northern areas of Europe, Asia and North America. It is strongly migratory and winters south of its breeding range to the equator...

, Common Teal

Common Teal

The Eurasian Teal or Common Teal is a common and widespread duck which breeds in temperate Eurasia and migrates south in winter. The Eurasian Teal is often called simply the Teal due to being the only one of these small dabbling ducks in much of its range...

, Dark-bellied Brent Goose, Grey Plover

Grey Plover

The Grey Plover , known as the Black-bellied Plover in North America, is a medium-sized plover breeding in arctic regions. It is a long-distance migrant, with a nearly worldwide coastal distribution when not breeding....

, Common Redshank

Common Redshank

The Common Redshank or simply Redshank is an Eurasian wader in the large family Scolopacidae.- Description and systematics :...

, Eurasian Curlew

Eurasian Curlew

The Eurasian Curlew, Numenius arquata, is a wader in the large family Scolopacidae. It is one of the most widespread of the curlews, breeding across temperate Europe and Asia...

, Dunlin

Dunlin

The Dunlin, Calidris alpina, is a small wader, sometimes separated with the other "stints" in Erolia. It is a circumpolar breeder in Arctic or subarctic regions. Birds that breed in northern Europe and Asia are long-distance migrants, wintering south to Africa, southeast Asia and the Middle East...

 and Black-tailed Godwit

Black-tailed Godwit

The Black-tailed Godwit, Limosa limosa, is a large, long-legged, long-billed shorebird first described by Carolus Linnaeus in 1758. It is a member of the Limosa genus, the godwits...

.

Mammals to be seen include Red Fox

Red Fox

The red fox is the largest of the true foxes, as well as being the most geographically spread member of the Carnivora, being distributed across the entire northern hemisphere from the Arctic Circle to North Africa, Central America, and the steppes of Asia...

 Vulpes vulpes, badger

Eurasian Badger

The European Badger is a species of badger of the genus Meles, native to almost all of Europe. It is classed as Least Concern for extinction by the IUCN, due to its wide distribution and large population....

 Meles meles, Grey Squirrel

Eastern Gray Squirrel

The eastern gray squirrel is a tree squirrel in the genus Sciurus native to the eastern and midwestern United States, and to the southerly portions of the eastern provinces of Canada...

 Sciurus carolinensis, and Hazel Dormouse

Hazel Dormouse

The Hazel Dormouse or Common Dormouse is a small mammal and the only living species in the genus Muscardinus....

 Muscardinus avellanarius.

Butterflies and rare moths include White Admiral

White Admiral

-Butterflies:These butterfly species are commonly called as White Admirals:*In America it refers to two of the three subspecies of Limenitis arthemis*In Europe and Asia it refers to the White Admiral: Limenitis camilla...

 Limenitis camilla, Chocolate-tip Moth Clostera curtula and Peach Blossom Moth

Peach Blossom

The Peach Blossom is a moth of the family Drepanidae. It is found throughout Europe and is a fairly common species in the British Isles....

 Thyatira batis.

The Stour estuary is the focus of a children's novel by Arthur Ransome

Arthur Ransome

Arthur Michell Ransome was an English author and journalist, best known for writing the Swallows and Amazons series of children's books. These tell of school-holiday adventures of children, mostly in the Lake District and the Norfolk Broads. Many of the books involve sailing; other common subjects...

, Secret Water

Secret Water

Secret Water is the eighth book in Arthur Ransome's Swallows and Amazons series of children's books. It was published in 1939.This book is set in and around Hamford Water in Essex, close to the resort town of Walton-on-the-Naze. It brings the Swallows and the Amazons together and introduces a new...

(1939).