The Parc National des Oiseaux du Djoudj (PNOD; 16,000 ha) forms the core of this site, which consists of an inland delta in a shallow depression lying within the flood-plain of the Senegal river, in north-western Senegal, on the border with Mauritania, where it is contiguous with Diawling National Park (MR021). The park lies about 60 km north-east of the city of St Louis and some 20 km north-west of the Ndiaël basin (site SN002). Objectives for the park include environmental education and promotion of ecotourism as well as wildlife conservation. The PNOD consists of an extensive complex of seasonally inundated brackish lakes and pools lying on impermeable saline soils and linked by channels to a branch of the Senegal river. It lies within the Sahel zone at sea-level and the terrestrial vegetation consists of Tamarix and Acacia savanna with a ground layer of herbs and grasses. Areas subjected to inundation support Typha, Sporobolus robustus, Phragmites and Nymphaea. The surrounding landscape outside the park is flat, open thorn-bush savanna used for livestock-rearing, hunting and some rice cultivation. There are seasonally inundated and marshy areas and small channels, especially adjacent to the river, and some of these are extremely important for birds in some years or at certain times of year, depending on flood and rain water-levels. These additional areas are therefore incorporated in the IBA and include an area known as ‘Débi’ to the north of the park and the ‘Zone d’intérêt cynégétique’ (or hunting zone) du Djeuss to the south. The IBA also extends downstream of the park along the river as far as the Maka Diama dam. Most of these areas are incorporated within the management plan for the PNOD and its buffer zone (see ‘Conservation issues’).
See Box for key species. The park is internationally important for breeding, staging and wintering waterbirds. The Wetlands International African Waterbird Census has recorded more than 200,000 waterbirds in January every year since 1992 (except 1996), with peaks of over 400,000 in 1992 and 1997. Around 95% of these numbers (i.e. 170,000 or more in most years) are migrant Palearctic wildfowl (Anatidae). Phoenicopterus minor has occurred regularly, and in increasing numbers in the park from 1993 (2,800 birds) to 1996 (11,655) with maximum counts of 15,000 and 46,500 in 1990. Small numbers of wintering Aythya nyroca have been recorded sporadically, with a maximum of 230 in 1972 and one record of 50 in 1991/92 (five-year mean of 12). Falco naumanni is a regular winter visitor and occurs on passage throughout the lower Senegal valley; it is often recorded from drier areas outside the park boundary. Numbers were highest in the 1950s and 1960s, but several hundred were seen more than once in the 1990s, peaking at 3,200 in 1994. Prinia fluviatilis is recorded as resident in the park, but there are no other details.Three other globally threatened species are recorded from the site. For Marmaronetta angustirostris there is one breeding record from 1979, but only sporadic individual sightings subsequently. Circus macrourus is apparently declining in comparison with previous decades; the maximum recent record is 15 birds in 1994. Acrocephalus paludicola was captured regularly in the reeds in the delta in the 1960s and 1970s and there are occasional more recent records from the 1980s and 1990s.The site also holds at least eight of the 12 species of the Sahel biome (A03) which occur in Senegal (see Table 2), including Ardeotis arabs, which is still seen regularly and breeds in the park, despite a marked decline in the north of the country since the 1960s. In addition to those in the Box, other waterbird species recorded in significant numbers close to IBA thresholds include Plegadis falcinellus, Platalea alba, Glareola pratincola and Limosa limosa. There is one record (not repeated) of 37,760 Dendrocygna bicolor in the park. Breeding birds include Pelecanus onocrotalus, Anhinga rufa (maximum 100 nests) and mixed colonies of Egretta garzetta, Casmerodius albus, Nycticorax nycticorax, Platalea alba, Mesophoyx intermedia and Threskiornis aethiopica. Many migratory passerines also use the site, e.g. roosts of up to 250,000 Motacilla flava. The site is closely linked with other wetlands throughout the delta of the Senegal river on both the Senegalese (e.g. sites SN002 to SN005 inclusive) and Mauritanian sides. Wetland species move between sites to forage and roost, and breeding numbers in any one year may also depend on relative water-levels in sites such as Djoudj and, in Mauritania, the Aftout-es-Saheli wetland and the Diawling Ramsar Site. The African Waterbird Census has covered all these major sites since 1995 and recorded considerable movements between PNOD and Diawling in particular. Ongoing counts should further demonstrate the complementarity of these sites and allow for fuller examination of numbers and movements of birds in relation to water-levels.
Non-bird biodiversity: Mammals include a small number of reintroduced Trichechus senegalensis (VU), which occurred naturally in the park until the 1980s, Gazella dorcas (VU) and G. rufifrons (VU).
Pressure/threats to key biodiversity
The park was placed on the ‘Montreux Record’ (the list of threatened Ramsar Sites requiring monitoring) in the late 1980s because of the perceived risk to water-levels resulting from the construction of the Maka Diama dam downstream of the park on the Senegal river. The dam (completed in 1986) prevents the flow of salt (sea) water up the Senegal river during the dry season, which used to reach several hundred kilometres upstream. Its intended function, together with Manantali dam in Mali, was to create an artificial annual flood in the Senegal river flood-plain, to mimic the natural processes, but this function has never been realized. Plans for extensive irrigated agriculture in the flood-plain, dependent on the dams and miles of constructed embankments and irrigation channels, have not been achieved on anything like the scale envisaged. The effect on the park, however, was to create a guaranteed supply of water, which was assured by the construction of a channel into the park from the river above the dam at Diama. As a result, the park was removed from the Montreux Record in 1988. However, it was returned to the Record in 1993, at the request of the Senegalese government, because of ecological perturbations arising from changes in the hydrological regime (the water-supply is now entirely fresh water where previously salt water entered the park during the dry season). In particular, large areas of previously open water have become infested with the weeds Pistia stratiotes and Paspalum vaginatum. Other threats to the integrity of the site include salinization of soils (resulting from the fact that there is no longer any ‘flushing out’ by floods) and pollution resulting from fertilizers and pesticides used in surrounding irrigated agriculture. There is also degradation due to livestock-grazing and loss of natural vegetation such as the ‘gonakier’ Acacia nilotica, exploited for fuelwood.A management plan was prepared in 1988 with the support of IUCN, WWF and the Netherlands Royal Institute for Nature Management. In 1997 the situation in the park improved considerably as a result of clearing out of water-supply canals and management to control weed on open water-bodies, coupled with good rains and a good flood-level in the river. A five-year integrated management plan, for the park and its buffer zone (‘Plan Quinquennal de gestion intégrée du Parc National des Oiseaux du Djoudj’), is currently being implemented (1995–1999) with further support from IUCN. This is based on a collaborative approach involving local communities in management of the park and buffer zone areas. A ‘Station Biologique du Parc National des Oiseaux du Djoudj’ was established in 1993 with support from IUCN, The Netherlands government, Fondation Friedrich Ebert, GTZ and two other German institutions (Biological Station of Zwillbrok and the regional Ministry of Environment of Northern Westphalia). Extensive research programmes are under way, including investigations into biological and mechanical control of the aquatic weeds in the park (funded by the European Commission) and regular bird surveys carried out by the Senegalese Direction des Parcs Nationaux in collaboration with the French Office National de la Chasse (ONC).Tourism (involving both international and Senegalese tourists) is very important to the park (for awareness-raising and as a source of revenue); visitors (from October to April) can number up to 100 a day. Facilities include an information centre, observation hides, a campsite and huts for accommodation, boat trips to see pelicans and flamingos and information leaflets. Tourism could pose some problems through disturbance to birds, especially breeding species, but to date it appears to be well regulated and organized.