Available online at http://www.ifgdg.org Int. J. Biol. Chem. Sci. 13(1): 34-48, February 2019 ISSN 1997-342X (Online), ISSN 1991-8631 (Print) Original Paper http://ajol.info/index.php/ijbcs http://indexmedicus.afro.who.int Spatial distribution and nesting behavior of the Black winged-stilt (Himantopus himantopus himantopus, Linnaeus 1758) in the urban wetland of Dakar Technopole (Senegal, West Africa) Aissatou Yvette DIALLO1, Papa Ibnou NDIAYE1* et Saliou NDIAYE2 1 Laboratoire de Biologie évolutive – Ecologie et gestion des écosystèmes, Département de Biologie animale, Faculté des Sciences et Techniques, Université Cheikh Anta Diop de Dakar, Sénégal. 2 Ecole Nationale Supérieure d'Agriculture (ENSA), Université de Thiès, Sénégal. *Corresponding author; E-mail: [email protected] / Phone: (+221) 778142834 ACKNOWLEDGMENTS The authors thank the Birdlife International who supported the study through a scholarship to AYD, used to carry out the fieldwork. ABSTRACT Wetlands are important areas in the conservation of biodiversity and play a key role in the ecosystems regulation. Thus, considering that climate change effects combined with anthropogenic pressures on natural resources are causing loss of biodiversity in Sahelian countries such as Senegal, we need to do regular stock assessments. For this, we aimed at studying the Black winged-stilt (Himantopus himantopus himantopus) in the urban wetland of Technopôle in the Niayes of Dakar (capital of the republic of Senegal). Our study is focused on the spatial distribution and nesting of the Black winged-stilt (Himantopus himantopus himantopus) in Technopole, which is classified in the list of Important Bird Areas (IBAs) by Birlife International since 2001 under A4i criteria and is an important biodiversity hotspot. The Niayes of Dakar constitute a particular ecosystem of wetland, they play a determining role in the reproduction and the survival of manies birds’ species. The nesting study was conducted from May to August 2012 and from May to August 2017. The maximum numbers of Black winged-stilt count during these periods are 531 individuals for 2012 and 766 individuals for 2017. However we highlight a decrease of the number of Black winged-stilt in the Technopole after the onset of the rains. Breeding data (25 nests in 2012 and 79 in 2017) show that this urban wetland is a preferred nesting site for Black winged-stilt. We report for the first time in this paper, so many Black winged- stilt nests in Senegal. Despite the disturbances related to anthropogenic factors, the breeding success of the Black winged-stilt reached 89.6% in May 2017. Thus, we believe that a strengthening of a conservation action plan of this site is urgent for a better preservation of the biodiversity, particularly the avian resources. © 2019 International Formulae Group. All rights reserved Keywords: Breeding, conservation, Himantopus himantopus, Niayes, water bird INTRODUCTION marvel of nature and a vital global resource Water birds, most often migratory, fly for animal biodiversity. In the Important bird very long distances during their annual and biodiversity areas (IBAs) of the Niayes of migration cycles and follow "migration Dakar. The few existing scientific studies routes" linking their breeding sites to other have reported a significant presence of birds areas important for their survival. They are a during a party of the year (Diallo, 2012; Diop, © 2019 International Formulae Group. All rights reserved. 8027-IJBCS DOI: https://dx.doi.org/10.4314/ijbcs.v13i1.4 A. Y. DIALLO et al. / Int. J. Biol. Chem. Sci. 13(1): 34-48, 2019 2012; Dione, 2014; Gadiaga, 2014). Breeding after four weeks after birth and become of Himantopus himantopus himantopus in independent two to four weeks later (Rihane, Technopôle were reported for the first time by 2007; Adamou et al., 2009; Birdlife Diallo (2012). However, presence of H. h. International, 2016). The main objective of himantopus in Senegal precisely in Saloum this study is to confirm the presence of Black Delta National Park (PNDS) were reported in winged-stilt in the Niayes of Pikine and first by Morel, they are more than 20 years. H. provide the first scientific data on its h. himantopus lives mainly near freshwater reproduction in this site. and salt marshes, in saltlick, shallow lakes, coastal lagoons, flooded fields and rice MATERIALS AND METHODS paddies. In this paper, we contribute to the Location of the study area production of data about this species in The Niayes system stretches along the Senegal, particularly in the urban wetland of main Senegalese coast to the heart of the Cape Technopôle (in Dakar, the capital of Senegal). Verde peninsula. The Niayes consist of inter- These data are about the distribution and dune depressions where the touch of the water reproduction of the Black winged-stilt, H. h. table is conducive to the development of a himantopus. According to Birdlife Guinean-type climate. It is a market garden, International (2016), H. himantopus is arboreal and poultry area of the first plan that represented by four subspecies: H. h. supplies the agglomerations of Dakar and himantopus, H. h. knudseni, H. h. melanurus surrounding areas. In the Dakar region, many and H. h. leucocephalus. The subspecies H. h. of the areas formerly occupied by the Niayes himantopus is made up of six groups that are (Figure 1a) have now disappeared because of the following: the strong demographic pressure. The - Group 1: himantopus, West and breeding data of Himantopus himantopus South-West Europe, West Africa presented in this document come from the - Group 2: himantopus, Central and urban wetland named Technopole East Europe, East Mediterranean (geographical coordinates 14° 45' 16.69'' N - Group 3: himantopus, South-West and 17° 24' 48.41'' W; Figure 1 b), which is Asia part of the Niayes of Dakar (the Niayes of - Group 4: himantopus, Sub-Saharan Pikine or Technopole, the catchment area, the Africa Mbeubeuss lake, the Retba lake, the - Group 5 : himantopus, Meridionalis Mbaouane lake and the Pink Lake or Tanma - Group 6 : himantopus, madagascar. lake). Technopole superficie is about 200 Only groups 1 and 4 concern Senegal. hectares. It is bordered to the north by the Group 1 is estimated between 71,000 and Golf-Nord district of Guediawaye, to the 82,000 individuals and group 4 is estimated south by the highway, to the east by the Pikine between 100,000 and 200,000 individuals. agglomeration and to the west by Camberene. The world population is estimated between The Technopole project on the Niayes 450,000 to 780,000 individuals. The species site was authorized by the Senegalese State by breeds generally in shallow freshwaters and Law No. 96-36 of December 31st, 1996. The brackish wetlands with substrates of sand, aim was to host research and teaching centers mud or clay and open margins, islets or spits as well as companies developing from the nearby water level. The nesting technological innovation. Thus, a protective period is between April and June. Female lays wall had been erected on the side of the four olive-green eggs stained with gray and highway. black. The incubation is biparental and lasts 22 to 26 days. At birth, the chicks are covered Physical aspect and biological resource of with dark down, with gray spots or blackish the study area brown. The lower parts are white. This The Niayes of Pikine belong to the juvenile plumage is preserved until the ninth sub-Canarian microclimate. Its climate is month. The chicks are nesting and leave the influenced by the maritime trade winds which nest to hide in the surrounding vegetation. are present all the year. These trade winds They are fed by both parents. They fly away mitigate seasonal thermal contrasts and soften 35 A. Y. DIALLO et al. / Int. J. Biol. Chem. Sci. 13(1): 34-48, 2019 temperatures (Touré, 2004). Annual rainfall is indicated in the Figure 2. Thus we made a generally between 300 and 500 mm and their systematic count of all the Black Winged-stilts average reaches 469 mm. Maxims are between 07:00 hr and 12:00 hr in each zone. recorded in August. The very short rainy This allowed us to locate the geographical season usually lasts three to four months. distribution of Black Winged-stilts in the Annual temperatures vary between 24.5 °C. Technopôle. Data on the geographical The warmest month of the year is October, distribution of Black Winged-stilts were with an average temperature of 28.1 °C and analyzed using ArcGIS 10.3 and R-3.3.3 February is the coldest month with an average software. temperature of 21.7 °C (Ndiaye et al., 2012). Vegetation is dominated by a typical Guinean Nesting behavior species, Elaeis guineensis, which marks the We identified the nests of Black contact zone between the bottom of the dune Winged-stilt simultaneously to the study of system and the depression. We also note the the spatial distribution of these birds. The presence of Cocos nucifera and a large main objective of the protocol was to monitor herbaceous layer conditioned by the the reproduction of the Black winged-stilt topography of the environment (Touré, 2004). population in the Niayes of Pikine, thus These Niayes interdunal depressions making it possible to specify the life cycle of are home to species with subguineous affinity the species (laying dates, number of eggs laid, (10%) such as Detarium senegalense, Kigelia dates of hatching and incubation time). Thus, africana, Antiaris africana, Malacantha we carried out a regular check of the nests and aulnifolia, and Sudanian (12%) Parkia their states of evolution. The parameters of biglobosa, Prosopis africana. whether or not the nest is occupied by the In this vegetation cover lives a very male or the female as well as the stage of diverse fauna, consisting of reptiles and soil reproduction (during laying or incubation) are organisms (protozoa, nematodes, rotifers, recorded.