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Diversity And Density Of Avifauna In Areas With Different Protection Status: A Case Study In Hadejia-nguru Wetlands, North-eastern Nigeria

Diversity and density are critical variables in determining the functioning of an ecosystem. Wetlands are among the ecosystems that are rich in biodiversity. However, in many Ramsar wetlands, such information is lacking. Bird species were assessed in

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  International Journal of Ecology and Environmental Sciences 44 (2): 117-125, 2018ISSN: 2320-5199 (Online)© N ATIONAL I  NSTITUTE OF E COLOGY ,    N EW D ELHI Diversity and Density of Avifauna in Areas with Different Protection Status:A Case Study in Hadejia-Nguru Wetlands, North-eastern Nigeria A.   S.   R  INGIM *, F.J.   M AGIGE AND J.R.M.   J OHN 2   13  Department of Biological Sciences, Federal University Dutse, P.M.B. 7156, Dutse, Jigawa State, Nigeria 1  Department of Zoology and Wildlife Conservation, University of Dar es Salaam, P.O. Box 35064, Dar es Salaam, 2, 3 Tanzania Email: 1 [email protected][email protected];  2 [email protected];  3  [email protected]* Corresponding author ABSTRACT Diversity and density are critical variables in determining the functioning of an ecosystem. Wetlands are among the ecosystemsthat are rich in biodiversity. However, in many Ramsar wetlands, such information is lacking. Bird species were assessed inProtected Areas (PAs) and Unprotected Areas (UPAs) of the Hadejia-Nguru Ramsar site between October and December, 2015using point count method. Ninety nine point count stations spaced 400 m apart with radius of 100 m were surveyed. A total of 42,255 individuals of birds belonging to 148 species, 50 families and 23 avian order were observed. Two globally threatenedspecies, the European Turtle Dove Streptopelia turtur   and Pallid Harrier Circus macrourus were observed. The former wascategorized as Vulnerable while the latter as Near Threatened based on IUCN Red List categories version 3. There was higher species diversity in the UPAs than in the PAs (t = -15.34, df = 40073,  p  <0.001). The two areas were similar in their speciescomposition by 81% indicating that these areas share a number of species. A relatively higher bird density was recorded in the PAs(7 individuals ha) than in the UPAs (5 individuals ha).. Both habitats are rich in avifauna and therefore deserve equal -1-1 conservation attention, , especially the Unprotected wetlands and the globally threatened species. .Key Words: Bird Diversity; Density; Hadejia-Nguru Wetlands; Protected and Unprotected Areas INTRODUCTIONProtected Areas (PAs) are described as geographicallydefined areas which are designated or regulated andmanaged to achieve specific conservation objectives(CBD 1992). Such areas can provide a refuge for birdspecies, in particular, threatened and endemic species of global conservation concern, and an essential tool for long term conservation of biodiversity (Evans et al.2006). Many studies pointed out that PAs serve toincrease bird species diversity and density in contrast toUnprotected Areas (UPAs) (Franco et al. 2007). Thus, bird diversity and density are expected to increase withincrease in the proportion of PAs by reducing habitatloss and other human pressures (Evans et al. 2006). Theglobal protected area network has over 160 000 PAs inexistence covering around 12.7% of the earth's terrestrialsurface comprising the global PA network (Rayner et al.2014).Some PAs fall within Ramsar sites, a collectivename given to a variety of wetland habitats includingswamps, marshes, riverbanks, ponds, coral reefs, andfloodplains, and are among the most productive eco-systems in the world (Barbier et al. 1997). In manycountries, these areas qualify for different types of conservation statuses, such as Important Bird andBiodiversity Areas (IBAs), Endemic Bird Areas (EBAs)and Key Biodiversity Areas (KBAs). In the Hadejia- Nguru Wetlands (HNWs), a Ramsar site and anImportant Bird Area (IBA) in Nigeria, four PAs: Adiani  Ringim et al.: Avifauna of Hadejia-Nguru Wetlands Int. J. Ecol. Environ. Sci.118 Forest Reserve, Baturiya Game Reserve, Chad Basin National Park, and Nguru Lake and Marma Channel arefound (Birdlife International 2015). Additionally, severalunprotected wetland areas, not legally protected are also present in HNWs, which are regarded as UnprotectedAreas (UPAs) in this study. Ezealor et al. (1997) have demonstrated that Ruff   Philomachus    pugnax is not a pest of rice Oryza  spp. inthe HNWs, despite rice being its main diet (30.5–37.8%)in this wetland. Akinsola et al. (2000) highlighted thatuncontrolled hunting, habitat loss and degradation areamong the major challenges facing waterbird conser-vation in the HNWs. Oduntan et al. (2010) reportedhuman – bird conflicts in this area. They further arguedthat fire arms and chemicals used by farmers incontrolling waterbirds are unsustainable as they either kill or injure them. Lameed (2011) brought out to lightthe bird diversity and abundance of Dagona WaterfowlSanctuary and the positive relationship betweenvegetation density and bird diversity. Sulaiman et al.(2015) reported that the size of wetland in this area doesnot have effect on bird abundance, but on bird diversity.Despite these important studies and increasing threats tothe ecology of wetlands, our knowledge on avian speciesdiversity and density in HNWs is scanty. The presentstudy aimed to document and compare avian speciesdiversity and density in PAs and UPAs of the HNWs. Itwas hypothesized that PAs will have higher birddiversity and density than UPAs. THE STUDY AREAThe study was conducted during October – December,2015 in HNWs located in the semi-arid region of North-eastern Nigeria. This wetland was formed where theHadejia and Jama’are rivers meet and form the Yoberiver, which drains into Lake Chad. The study area lies between Latitude 12 10’ N and 130’ N and Longitudes oo 1015’ E and 11 30’ E (Figure 1), with an extent of 350, oo 000 hectares. It is situated between altitudinal range of 152–305 m above sea level. This wetland is the first andmost important Ramsar wetland in Nigeria and amongthe most valued Ramsar wetlands in West Africa byserving as home to both resident and migratory birdsespecially waterbirds (Birdlife International 2013). Thevegetation in this area is Sudan savanna consisting of sparse shrubs and isolated tall trees predominantly  Acacia spp. Annual rainfall ranges between 500– 600mm (Ogunkoya and Dami 2007). METHODSFourteen (14) wetlands, 7 in each area, were selected.The PAs wetlands included Gwayo, Kwasabat,Kandamau, Maram, Marma Channel, Nguru Lake andOxbow Lake were identified. Whereas Barrack,Dumbari, Hadejia Barrage, Kacallari, Kirikasamma,Muzza and Zemo were in the UPAs. A total of 48 and 51census point stations were established in PAs and UPAsrespectively. Field visits were made in the morning from06:00 to 10:00 h and in the afternoon from 16:00 to18:00 h when birds were more active. Point countmethod, as described by Bibby (2000), was used tosample birds. Birds seen and heard were recorded froma fixed point for 10 minutes within 100 m radius. Pointcount stations were spaced 400 m apart to avoid doublecounting. Observations were carried out using BraunBinoculars (16 x 50 m) and birds were identified usingfield guide to the birds of Western Africa by Borrow andDemey (2014). Data Analyses Paleontological Statistics (PAST version 2.17, Hammer et al. 2001) was used to compute species diversity usingShannon-Weiner diversity index. Special t  - test was usedto compare species diversity between PAs and UPAs.Jaccard’s index was used to measure species similarity between PAs and UPAs according to Chao et al. (2005)following the formula given below: Where, Sa and Sb are the numbers of species in the PAsand UPAs, respectively, and Sc is the number of speciescommon to both areas. Population Density (PD) wasdetermined following Sutherland (1996) as: Comparison of bird diversity and density between PAsand UPAs was done using student t  - test.Avian species were categorized as resident, intra-African migrants or Palearctic winters according toBorrow and Demey (2014) and Dowsett et al. 2016).These birds were further categorized on the basis of their dependency on wetland environment, i.e. WetlandGeneralist (WG) those that frequently visit wetlands for   44: 117-125 Ringim et al.: Avifauna of Hadejia-Nguru Wetlands 119 Figure 1. Sampling sites in PAs and UPAs of the Hadejia-Nguru Wetlands)   food or water, and Wetland Specialist those that adapt towetland environment entirely for their life (Mutagwaba2010).RESULTSA total of 42,255 individuals of birds belonging to 148species, 50 families and 23 avian orders were recorded in the whole study area of the HNWs (Table 1).Unprotected areas had higher species diversity (  H'   =1.98, evenness = 0.0456) than the PAs (  H' =  1.70,evenness = 0.0556) (t = -15.34, df = 40073,  p  <0.001).These two areas were similar in terms of bird speciescomposition by 81% indicating that the areas share anumber of species. Bird abundance was higher in PAsthan in the UPAs (see Table 1). Families with the highestspecies were Accipitridae (13 species), Ardeidae (11species) and Columbidae (9 species). Two species of global conservation concern were also recorded: the Near Threatened Pallid Harrier Circus macrourus andVulnerable European Turtle Dove Streptopelia turtur; the former was recorded in both areas i.e. PAs and UPAswhereas the latter was only recorded in PAs. Threeindividuals were recorded in PAs, whereas fiveindividuals were recorded in UPAs. Twenty eightindividuals of the Vulnerable European Turtle Dove, Streptopelia turtur were recorded in December in thePAs. Further, 14 species including S. turtur   wererecorded for the first time in HNWs (Table 2). Table 2 shows the bird abundance in both PAs andUPAs as categorized by their status: resident species,Intra-African migrant or Palearctic winter, and their dependency on wetland environment.A relatively higher bird density was recorded in thePAs (7 ha), whereas only 5 ha in the UPAs; but the -1-1 difference was not statistically significant (t = 0.3813, df = 264,  p  = 0.7032). Overall density of birds in PAsranged from 0.02 to 239.47 individuals ha, and in the -1 UPAs from 0.01 to 119.99 individuals ha (see Table 1). -1 The White-faced Whistling Duck  Dendrocygna viduata (239.47 individuals ha) had higher density in PAs -1 whereas in UPAs, and Garganey Spatula querquedula had higher density (see Table 1).  Ringim et al.: Avifauna of Hadejia-Nguru Wetlands Int. J. Ecol. Environ. Sci.120 Table 1. Checklist of bird species recorded in PAs and UPAs of the HNWs, new additions to existing studies (*)  Protected areas Unprotected areasFamilySpecies NameNo. of individualsDensity haNo. of individualsDensity ha -1-1 AnatidaeAfrican Pygmy Goose  Nettapus auritus 220.03120.19Fulvous Whistling Duck  Dendrocygna bicolor  931.61560.97Garganey Spatula querquedula 521090.45610399.72Knob-billed Duck Sarkidiornis melanotos 1983.431061.73Spur-winged Goose  Plectropterus gambensis 1662.88310.5White-faced Whistling Duck  Dendrocygna viduata 13794239.477344120Apodidae African Palm Swift Cypsiurus parvus 781.35110.17Common Swift  Apus apus 20.03-0-Little Swift  Apus affinis 10.01190.31Bucerotidae African Grey Hornbill  Lophoceros nasutus 100.17110.17 Northern Red-billed Hornbill Tockus erythrorhynchus 230.39190.31Accipitridae African Harrier Hawk  Polyboroides typus 10.0110.01African Swallow-tailed Kite Chelictinia riocourii* --20.03Black Shouldered Kite  Elanus axillaris --60.09Black kite  Milvus migrans 70.1270.11Dark Chanting Goshawk  Melierax metabates --20.03Gabar Goshawk  Micronisus gabar  20.0340.06Grasshopper Buzzard  Butastur rufipennis --20.03Lizard Buzzard  Kaupifalco monogrammicus --50.08Montagu's Harrier Circus pygargus 20.03--Pallid Harrier Circus macrourus 30.0550.08Shikra  Accipiter badius 20.03--Western Marsh Harrier Circus aeruginosus 80.13130.21Yellow-billed Kite  Milvus migrans parasitus 10.0110.01CiconiidaeAbdim's Stork Ciconia abdimii 400.6930.04African Openbill Stork  Anastomus lamelligerus 60.1100.16White Stork Ciconia ciconia --110.17CuculidaeGreat Spotted Cuckoo Clamator glandarius --40.06Senegal Coucal Centropus senegalensis 50.08280.45ColiidaeBlue-naped Mousebird Urocolius macrourus --100.16AlcedinidaeAfrican Pygmy Kingfisher  Ispidina picta 50.0820.03Grey-headed Kingfisher  Halcyon leucocephala 40.06--Malachite Kingfisher Corythornis cristatus 90.1530.04Pied Kingfisher Ceryle rudis 90.1550.08ColumbidaeAfrican Mourning Dove Streptopelia decipiens 3596.231632.66Black-billed Wood Dove Turtur abyssinicus 50.0810.01Blue-spotted Wood Dove Turtur afer  --10.01European Turtle Dove Streptopelia turtur* 280.48--Laughing Dove Streptopelia senegalensis 180.31280.45 Namaqua Dove Oena capensis 20.0350.08Speckled Pigeon Columba guinea 70.12190.31Tambourine Dove Turtur tympanistria* 20.03--Vinaceous Dove Streptopelia vinacea 50.0860.09CoraciidaeAbyssinian Roller Coracias abyssinicus 140.24200.03CharadriidaeBlack-headed Lapwing Vanellus tectus 30.05190.31Spur-winged Lapwing Vanellus spinosus 320.55621.01JacanidaeAfrican Jacana  Actophilornis africanus 2053.552564.18Lesser Jacana  Microparra capensis 130.2290.14LaridaeGull-billed Tern Gelochelidon nilotica* 200.3420.03  44: 117-125 Ringim et al.: Avifauna of Hadejia-Nguru Wetlands 121  Protected areas Unprotected areasFamily Species NameNo. of individualsDensity haNo. of individualsDensity ha -1-1 Grey-headed Gull  Larus cirrocephalus* 40.06--Whiskered Tern Chlidonias hybrida 70.1230.04ScolopacidaeCommon Sandpiper  Actitis hypoleucos 40.0620.03Common Snipe Gallinago gallinago --50.08Green Sandpiper Tringa ochropus 290.5791.29Little Stint Calidris minuta --380.62Ruff Calidris pugnax 60.1711.16Spotted Redshank Tringa erythropus 60.1631.02Wood Sandpiper Tringa glareola 3796.5765310.66RecurvirostridaeBlack-winged Stilt  Himantopus himantopus 581330.53FalconidaeGrey Kestrel  Falco ardosiaceus --20.03Lanner Falcon  Falco biarmicus 40.0630.04Red-necked Falcon  Falco ruficollis 10.0140.06 NumididaeHelmeted Guineafowl  Numida meleagris* --120.19OdontophoridaeStone Patridge  Ptilopachus petrosus --60.09RallidaeAllen's Gallinule  Porphyrio alleni 330.5750.08Black Crake  Zapornia flavirostra 430.74110.17Common Moorhen Gallinula chloropus 260.45180.29Lesser Moorhen Gallinula angulata 100.1780.13Purple Swamphen  Porphyrio porphyrio 330.57120.19MusophagidaeWestern Grey Plantain-eater Crinifer piscator  30.0560.09LybiidaeBearded Barbet  Pogonornis dubius 20.03--Vieillot's Barbet  Lybius vieilloti 10.0120.03Yellow-fronted Tinkerbird  Pogoniulus chrysoconus 10.01--ArdeidaeBlack Heron  Egretta ardesiaca 801.38150.24Black-headed Heron  Ardea melanocephala 110.1930.04Cattle Egret  Bubulcus ibis 190.32390.63Great Egret  Ardea alba 50.08160.26Green-backed Heron  Butorides striata 100.1730.04Grey Heron  Ardea cinerea 100.17180.29Intermediate Egret  Ardea intermedia 120.2130.21Little Bittern  Ixobrychus minutus 30.0510.01Little Egret  Egretta garzetta 160.27210.34Purple Heron  Aredea purpurea 420.72230.37Squacco Heron  Ardeola rolloides 1492.58631.02ThreskiornithidaeGlossy Ibis  Plegadis falcinellus 310.53390.63PsittacidaeRed-headed Lovebird  Agapornis pullarius* 30.05--Rose-ringed Parakeet  Psittacula krameri 60.170.11Senegal Parrot  Poicephalus senegalus 60.130.04PteroclidaeFour-banded Sandgrouse  Pterocles quadricinctus 40.06631.02CaprimulgidaeStandard-winged Nightjar Caprimulgus longipennis* 20.03--UpupidaeHoopoe Upupa epops 10.0110.01PhaoeniculidaeGreen Wood-hoopoe  Phoeniculus purpureus 10.0170.11AlaudidaeCrested Lark Galerida cristata 30.05130.21CisticolidaeGrey-backed Camaroptera Camaroptera brachyura --10.01Tawny-flanked Prinia  Prinia subflava 50.6550.07Zitting Cisticola Cisticola juncidis --40.06Winding Cisticola Cisticola galactotes 10.0150.08CorvidaePiapiac  Ptilostomus afer  --230.37Pied Crow Corvus albus 10.01150.24EstrildidaeCut-throat Finch  Amadina fasciata 70.1230.04Green-winged Pytilia  Pytilia melba* 10.0120.03