The Dokka Delta nature reserve

The Dokka Delta Ramsar area nature reserve is protected primarily due to the area’s importance to migratory and nesting wetland birds. It is an important area for migration routes over South Norway and over 220 bird species have been observed in the area.

The Dokka Delta was first protected as a nature reserve in 1990 and gained Ramsar status in 2002. The river delta represents the River Etna’s and the River Dokka’s outlet into the Randsfjorden. The rivers have built up a large delta area consisting of the two main channels and a range of features such as embankments, smaller channels, meanders and swamp areas. The area was previously used as pasture and for hay making, and this cultural influence is still evident. The Dokka Delta is different to most other large inland deltas in that its landscape is mostly influenced by traditional farming practices and nature regeneration processes, rather than direct human intervention.

The delta is easily accessible and is used for outdoor recreation such as boating and fishing. There are some important cultural heritage sites within the delta. Industry in the delta includes forestry and logging, with a railway line running through the area.

 

The Dokka Delta is one of the largest and most important resting areas along one of the main migration routes across Østlandet for migrating wetland birds. The drying of the mudbanks in April and May increases the availability of food resources, with the delta's high biological productivity providing nutrition for significant concentrations of many different bird species. A number of rare, vulnerable and threatened species take advantage of the conservation area, and a total of 56 species from the Norwegian Species Red List 2015 have been observed. During the spring migration the delta is used by large numbers of a variety of bird species, including great crested grebes, pink-footed geese, Eurasian teals, tufted ducks, common cranes, golden plovers and common greenshanks. The delta’s varied wetland habitats result in a species rich fauna of nesting birds in the conservation area. Wetland birds, raptors, owls, and perching birds as well as some harder to spot species such as tufted grebes, northern shoveler, garganey, short-eared owl, tawny owl, lesser spotted woodpecker, Eurasian wryneck and common rosefinch all find places to nest within the delta area. The autumn migration starts in August and lasts until the first freeze of winter in November. There are often significant numbers of artic waders to be found in the area during the autumn of years with low water levels. The grey plover, red knot, little stint, curlew sandpiper are examples of such species. Dabbling and diving ducks, geese and swans all use the area until the formation of the first ice pushes them further south. In addition, many perching bird and predatory bird species pass through the delta in autumn. The autumn migration sometimes features appearances of rare species like the red-necked grebe, smew, western marsh harrier, red-footed falcon, little gull and razorbill.

Mammals including elk, badger, roe deer, mink, weasel, red fox, stoat, squirrels are permanent residents in the delta. There have been regular observations of common lizards, smooth newts, common frogs and toads. The eleven fish species which are present in Randsfjorden are pike, trout, Arctic Char, roach, ninespine stickleback, perch, smelt, brook lamprey, minnow and whitefish.

 

Mute swan in the Dokka Delta. Photo: Thor Østbye