The return of the water - IUCN

The Return of the Water
brought to Maroua town from the Waza Division alone (Madi Ali and Peters, 2001). The continuation
of fire wood collecting may pose a threat to the continued existence of the remaining bush in the
floodplain area. In some parts of the floodplain, the bush has been cleared in order to grow more
dry season sorghum (‘muskwari’).
The area of the Waza Logone project primarily includes the inundated floodplains and encompasses
the entire Waza National Park. The floodplain habitat of the Waza National Park was seriously
threatened by the altered flooding patterns caused by the dam at Maga and declining rainfall. It is
therefore not surprising that over the years the Waza National Park has been the focus of scientific
research. Before turning to this particular species-rich area in the floodplain, the importance of the
floodplains as a whole for migratory birds will be discussed.
6.2 Bird life
The seasonal migration of Palaearctic birds to tropical Africa is quite well known, although the
reason that birds undertake such impressively long flights is only recently being understood. Wetlands
in particular are attractive staging areas for migrant water birds. The Logone floodplain in particular
is visited by numerous Palaearctic birds, which spend the wintertime foraging in the grasslands.
Waterfowl censuses have been carried out in the Lake Chad basin since the 1980s, to act as indicators
of the importance of these wetlands. The southern floodplains of Lake Chad appear indeed to be
important foraging areas for hundreds of thousands of birds (Table 6.1). The Logone floodplain
supports considerably more water birds than the Hadejia-Nguru floodplains in Nigeria. Before 1990
four species, garganey (Anas querquedula), pintail (Anas acuta), white-faced whistling duck
(Dendrocygna viduata) and ruff (Philomachus pugnax), together accounted for 88 to 96% of all
birds counted in the Logone floodplain and the southern part of Lake Chad. In 1993, Pintail did not
even represent 1% of all birds counted, and only ruff (29%) was still present in large numbers,
followed by squacco heron (Ardeola ralloides) with 11%, white-faced whistling duck at 6% and
little stint (Calidris minuta) at 5%. Thirteen more species, each with numbers between 2 to 4% of
the total number of birds counted, made up another 28% of the total number of birds (Van Wetten
and Spierenburg, 1998). In addition, the man-made lake at Maga has become an important staging
area for large numbers of birds. One of the bird studies suggested that the irrigated rice fields, too,
have become extremely important habitats for water birds (OAG Munster, 1991).
The Convention on Wetlands (commonly called Ramsar) provides criteria for identifying
internationally important wetlands (Davis, 1994). Such wetlands should regularly support at least
20,000 waterfowl, or should support at least one per cent of the individuals in a population of one
species. The Lake Chad Basin as a whole with around one million visiting water birds (see Table
6.1) should thus be considered an important wetland area under the Ramsar Convention. Within this
large area, however, there are several distinctive locations that each may support tens of thousands
of waterfowl. During the waterfowl count of 1993, for instance, the minimum estimate of waterfowl
birds in the 40,000 ha Zilim/Zimado depression narrowly exceeded this threshold number. If, however,
the estimates based on the median of the counts are used, the Lake Maga and the Tekele depression
by far exceeded this threshold (see Tables 4.9 and 4.10 in Van Wetten and Spierenburg 1998). Also
the Waza National Park is an important staging area for water birds (see Table 6.2), even though
half of the Park’s area is unsuitable as habitat for most waterfowl. More importantly, however, the
western black crowned crane (Balearica p. pavonia) is resident in the park and the surrounding
areas. The total world population of this species is estimated at 15,000 individuals (Wetlands
International, 2002), of which almost 12 percent occur in the Logone floodplain (Unpublished count
carried out by the Waza Logone project/Ecole de Faune in 1997). Other species that meet the one
per cent criteria in the Logone floodplain area are: the West African populations of white pelican
(Pelecanus onocrotalus) and long-tailed cormorant (Phalacrocorax africanus), each with about two
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