Tréca, Bernard

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WETLANDS. HABITATS IN WEST AND CENTRAL AFRICA 
by Dr. Bernard TRECA 
ORSTOM 
B.P. 1386 DAKAR 
SENEGAL 
1 INTRODUCTION 
In W Africa, Crowned cranes' concentrations exist in 2 main areas, Senegambia 
and the Chad basin, with intervening area sparsely populated. According to URBAN 
and al, 1986, numbers in W Africa reduced during 1970s ; total population Senegambia 
and Mauritania, 2500-3500 ; Mali, Upper Volta, Ivory Coast, Ghana and Niger 
combined, only a few thousand at most ; NE Nigeria, low hundreds ; now probably 
extinct in most of former Nigeria range. Status, 1980s in W Africa (Balearics pavonina 
pavonina) threatened in parts of its range or on verge of extinction, e.g. Nigeria. 
2 CROWNED CRANE'S HABITATS AND FOOD 
Crowned cranes inhabit dry and wet open areas including marshes, damp fields 
and open margins of lakes and rivers ; they are rarely associated with open water. They 
roost in trees. Feeding grounds may be several km away, although sometimes within 
walking distance (URBAN and al, 2986). These birds feed most often on the cultivation 
aiid they arc also to be met with frequently on the sandy beds of the rivers or on their 
banks (BANNERMAN, 1931). 
* Food : Mainly live prey, according to BOUET, 1955. MACKWORTH-PRAED 
and GRANT, 1970, note small reptiles and large insects (locusts and grasshoppers). But 
crane is also fond of plant material, rice and water lilies' seeds (BOUET, 1955) and is 
often encountered feeding on cultivation (BANNERMAN, 1953). The biggest 
concentrations I personnaly saw were always on dry ploughed rice fields. 
. - -  - 
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CLIISSER: 
Rapport de mission au Nigeria (23/02 - 03/03/1992) 
Bernard TRECA 
a conférence internationale sur la grue couronnée et ses 
habitats humides en Afrique de l'ouest et centrale s'est tenue 
au Bagauda Lake Hotel de KANO, au nord du Nigeria, du 24 au 
27/02/1992. Cette conférence financée par l'ambassade des 
Pays-Bas au Nigeria a réuni une centaine de personnes parmi 
lesquelles on peut citer Richard BEILFUSS, des USA, 
représentant l'International Crane Foundation, Phillip HALL, 
eur technique de la Nigerian Conservation Foundation, Dr 
MUSTAPHA, du Ministry of agriculture and natural 
resources Kano State, Nigeria. Le SOUDAN et 1'Ethiopie étaient 
ent repr6sentés. 
Cette conférence à laquelle j'étais invité (billets 
' d'avion fournis) avait pour but de formuler des 
recommandations afin de stopper le déclin rapide des 
populations de grues couronnées. I1 s'agissait de discuter des 
causes du déclin dans pratiquement toute l'aire de 
répartition, en Afrique sub-saharienne, a cause principalement 
de la perte d'habitats favorables due aux importants travaux 
d'aménagement hydro-agricoles, et du braconnage) et de 
recommander une strategie d'action. 
a grue couronnée est ici considérée comme un symbole 
- -  représentatif ae _toutes les populations droiseaux d'eau. Etant 
trBs -sensible aux changements de l'environnement, elle peut 
servir d'indicateur d'un environnement sain. Dans ce sens, la 
,conf&rence était tout h fait dans l'axe de mes travaux actuels 
sur les possibilités d'adaptation des populations d'oiseaux 
aux modifications des milieux humides côtiers et deltaïque. 
La langue utilisée fut uniquement l'anglais. Premier 
orateur prendre la parole après le discours d'ouverture par 
,, M. Alh. Balarabe Aliyu Soron DINHI, Honorable Commissioner of 
Agriculture, Natural Resources , jrai present6 une 
communication sur "Wetlands habitats in West and Central 
est ressorti des différentes communications et 
ions que beaucoup restait h faire sur le plan des 
recensements, de la connaissance de la biologie et de 
l'écologie de la grue couronnée (donc sur les recherches de 
t sur l'education des populations rurales. 
cours de la deuxième journée, deux sous-comités furent 
pour discuter et formuler des recommandations. Le 
premier concernait les strategies pour la conservation des 
grues' couronn6es et de leurs habitats dans toute la sous- 
région. Le deuxième dont on m'a demandé d'assurer La 
I 
(voir texte ci-joint). 
présidence (chairman) 
sur les grues et leurs 
concernait l'éducation et la recherche 
habitats dans toute la sous-région. 
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Parmi les principa-ss recommancJ ions, on peut retenir : - la recherche des données numériques de base par deux 
recensements annuels (août et février) ; - la création d'un centre de coordination pour rassembler les 
résultats des recensements dans chaque pays ; - la recherche des sites importants pour la survie des grues 
couronnées (par exemple en fin de saison sèche) ; - la recherche des besoins des populations rurales vivant dans 
les mêmes zones que les grues ; - la recherche des zones de reproduction et une étude des 
modalités de reproduction dans chaque pays ; - le renforcement des lois de protection ; - 1'4ducation du public par tout moyen audiovisuel approprie ; - des enquêtes sur l'usage des pesticides ; - une étude d' impact sur 1 environnement avant tout 
aménagement hydro-agricole important ... 
Le texte des différentes communications et les 
recommandations seront publiées dans des Proceedings. 
Les 27 et 28 février, nous avons été rendre une visite de 
politesse au vice gouverneur de l'état de Kano, puis a Sa 
Majest6 18Emir de KANO. Puis une visite des zones humides de 
la région de HADEIJIA-NGURU pres de la frontiere avec le TCHAD 
fut couplée avec un relâcher de 2 grues couronnées venant du 
Parc zoologique, devant une très importante population locale 
et avec un maximum de publicité. 
J'ai eu quelques difficultés pur- trouver une place dans 
un avion pour rentrer au Sgwégal où je suis finalement arrivé 
avec 3 jours de retard. 
3 
3.1 
RECENT CHANGES IN WEST AND CENTRAL AFRICA’S HABITATS. 
climatic changes in the Sahelian zone 
A study of the mare d’Oursi, in Burkina Faso, is said to be representative of the 
conditions that prevail in a great part of the West Africa’s sahelian zone. According to 
this study by CLAUDE and al, 1991, the climatic aridity has been emphasized since the 
early 1970s by a drought exceptional by its length, by its severity, and by its large 
geographical generalisation. During the past two decades, one has witnessed a reduction 
of the total quantity of rain and a decrease in the number of .rainy days. That, along with 
a defacement of soil conditions, bring to an even more severe climatic aridity of the 
sahelian zone. 
3.2 Human pressure 
The continuous increase of the human population leads, noticing the impact of 
the recent drought’s years and the practical management of the environnement, to a 
dilapidation of that one which, in some cases, may be thought to be irreversible. 
Cultivated areas have extended at the same rythm that demographical increase. Live- 
stock increases also and pastoral space is becoming saturated (CLAUDE and al, 1991). 
One may think that the space for crowned cranes and the security they need are 
lessening at the same time. Trees where cranes usually roost have heavily suffered from 
drought and from human utilisation for fuelwood, charcoal and building. It has been 
estimated that for one ha of trees planting, 29 ha are destroyed (DOYEN, 1988). 
3.3 Non controled hunting / wars 
Legal hunting is not a serious threat for crowned cranes since hunting’s legislation 
in most countries forbids cranes’ shooting. But we got examples where poachers have 
been caught while carrying live or dead crowned cranes (FRY, 1974). Live cranes are 
sometimes kept in captivity for recreational use. In a number of countries, the Forestry 
Commission has too small financial funds to actually control the hunters. In some 
countries, the war bring soldiers in the fields without any possible supervision. 
3.4 Quantity of available food (antilocusts spraying) 
Aerial spraying have extended during the past decades in order to fight the 
locusts swarms which were one of the main food sources for crowned cranes. Besides the 
possible direct poisonning of cranes eating sprayed locusts, the lack of food (large 
insects) may have a real impact on cranes’ population. 
The area sprayed in 1988/1989 is greater than the cultivated area because some parts 
have been sprayed twice or more. By mean, 2 500 000 ha per country have been sprayed 
in 1988/1989 in Mali, in Niger, in Chad and in Mauritania. In Senegal, only 246 640 ha 
sprayed. In Burkina Faso and in the Cape Verde Islands, although there have been 
. locusts’swarms, no extensive spraying occured (A. NDIAYE, personnal communication). 
3.5 
3.5.1 SENEGAL 
More informations about recent changes in some countries 
Two dams have recently been built on the Senegal river. Manatali’s dam, in Mali, 
will retain the flood and permit the irrigation of a huge area for agricultural 
development. Diama’s dam will retain salted water from the sea from going upstream. 
Water, now available the whole year round, permits the development of numerous rice 
schemes, often where marshes and other wetlands were good cranes habitats. Dikes and 
embankements of rivers and lakes allow more water to be kept for agricultural or city 
use, but the increase of water level (e.g. Senegal river or Guiers’lake) is a loss of habitats 
for numerous species of birds including crowned cranes. 
The war with Mauritania has lead to human populations’ displacement and the 
need for about sixty thousand people from Mauritania to find new cultivable land in the 
north of Senegal. Wetlands are heavily looked upon since most of these refugees intend 
to grow irrigated rice. 
As for the Djoudj national Park, where crowned cranes breed, there is now a 
need for water management. Water is available in quantity because of the dams on the 
Senegal river, but changes in the environnement have been recorded recently. 
Particularly ponds and water-levels are overgrown with vegetation : Pistiu stratoides 
which is a kind of floatting "salad", Typhus and Phragmites, Cypevus articulutus and 
alguae. 
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3.5.2 MAURITANIA 
1 The creation of the Diawling's National Park seems to be a goocl thing in view of 
wetlands' conservation, but it is not yet really in function. The war with Senegal does not 
allow us to know exactly.what is happening there. There are still crowned cranes in the 
neighbouring Keur Macene, once a hunting center, but army's occupation of that place 
may lead to a slaughter of some birds ... According to STUART and al, 1990, The 
country's wetlands are at risk from droughts and increasing human use, as well as 
irrigation. 
3.5.3 MhBILH 
The severe drought in the Sahelian zone has achieved the dry out of the northern 
lakes and accentuate the human population increase in the remaining wetlands, further 
south. The remaining lakes which are yet flooded annualy are usualy cultivated with 
subsidence millet. The Inner Niger Delta would best be managed through a carefully 
designed multi-use programme, with reserve at a few well chosen localities, such as Lake 
Debo, Lake Horo and Seri, where Ramsar Sites have been establisehd (STUART and 
al, 1990). 
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3.5.4 BURKINAFASO 
The only large lake, the Mare d'Our$ is now rather intensively cultivated and 
human population has noticably increased. There are proposals (STUART and al, 1990) 
for new ornithological reserves at Beli and Mare d'Oursi. The effects of irrigation 
projects on wildlife should be monitored, particularly in the north of the country. 
3.5.5 NIGER 
According to STUART and al, 1990, Niger is one of several sahelian countries 
that has suffered very severe degradation of its natural resources as a consequence of 
droughts and overgrazing by livestock ... "W" National Park is one of the key areas fort 
conservation of savanna in West Africa. Further to the north along the Niger River are 
some other important habitats for wildlife ... Importants wetlands exist in the southeast 
around Lake Chad, but these are not currently the subject of any conservations 
initiatives. There are numerous seasonal wetlands or "mares" with ponded water, which 
are often wooded, across the Sahel zone. These are extremely important for wildlife, 
particularly birds, and need to be evaluated. 
3.5.6 NIGERIA 
Nigeria has many important wetlands sites, particularly in the north, e.g. Lake 
Chad, the Hadejia-Nguru Wetlands a n d  others in many areas, including around Kano. 
Current problem which need adressing, according to STUART and al, 1990, include 
sustainable use of wetlands resources by local people and the ecological implications of 
irrigation schemes (in the north of the country). 
3.5.7CAMERQON 
Water management schemes in the north have disruped natural flooding regimes, 
with a resultant serious deleterious effect on species and habitats. In Waza National 
Park, there have been decreases of wildlife owing to the reduced flooding of the plains 
since the creation of a dam on the Logone River (STUART and al, 1990). 
3.5.8 CHAD 
Due to the drought, cattle go now further south, where there is still water and 
pasture to feed on. That leads to an important population increase in some places that 
were good habitats for crowned cranes. STUART and al, 1990, note that several 
wetlands areas in the country are at risk from pressure to pursue intensive irrigated 
agriculture, and increasing use of pasture and fisheries resources. Also Chad's critical 
sites have become seriouly compromised as a result of disturbances to the protected area 
network during the civil war. 
3.5.9 CENTRAL AFRICAN REPUBLIC 
There are floodplains in the north which need conservation assesment and 
appropriate conservation measures implementing, including anti-poaching measures in 
the wet season (STUART and al, 1990) 
4 CONCLUSION AND PROSPECTS 
Habitat's í-eduction, decrease of abundance and availability of food may 
sometimes lead to a concentration of cranes. In the Djoudj National Park, in Senegal, 
one can see nowadays more cranes thail previously, but that may well be a simple effect 
of the loss of habitats and of thc conccntration of cranes where there are still favourable 
places to live. 
History does not repeat itself and the recurrence even for a long time of 
satisfactory climatic conditions will not be enough to resolve these regions problems. 
The environment's capacities as for the number of living human or animals and 
production have been seriouly reduced ... One has to know that every development 
action which will not meet human population agreement will inevitably lead to a 
disaster. 
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The need is great for a common strategy, for a research's coordination, for a 
census of populations and the diffusion of results in the different countries involved. The 
monitoring of cranes' populations needs an urgent agricultural - conservation - fishing 
and hunting coordination. 
5 BIBLIOGRAPHY 
BANNERMAN D.A., 1931, The birds of tropical West Africa 
vol. II, 
The crown agents for the colonies, London, 428 p. 
BANNERMAN D.A., 1953, The Birds of west and Equatorial Africa, 
Vol I, 
Oliver and Boyd, Edinburgh, 7% p. 
BOUET G., 1955, Oiseaux de l'Afrique tropicalc, 
(première partie), 
Faune de l'Union française, Office de la recherche scientifique et technique outre-mer, LAROSE, 
PARIS, 412 p. 
CLAUDE J., GKOUZIS M. et MILLEVILLE B. (Eds), 1991, Un espace sahélien, la mare d'Oursi, 
Burkina Faso. 
Ed. ORSTOM, 241 pp -k cartes 
DOYEN A., 1988, Les problèmes forestiers dans les pays du Sahel, 
Environnement africain, no 23-24, vol. VI, 3-4 : 97 - 109 
FRY, C.H., 1974, West african crowned crane status, 
Crane research around the world, 251 - 253 
MACKWORTH-PRAED C.W. and GRANT C.H.B., 1970, Birds of west central and wcstcrn Africa, 
African Handbook of birds, series 3, vol I, 
LONGMAN, London, 671 p. 
STUART S.M., ADAMS R.J. and JENKINS M.D., 1990, Biodiversity in Sub-Saharan Africa and its 
Islands, 
Conservation, Management and Sustainable Use 
Occasional papers of the UICN Species Survival Commission, n06, UICN, 246 p. 
URBAN E.K., FRY C.H. and KEITH S., 1986, The Birds of Africa, vol II, 
Academic Press, London, 552 pp. 


Conférence internationale sur la grue couronnée et ses habitats humides en Afrique de l'Ouest et Centrale

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