Urbanisation, Bird Species Richness and Abundance Within Ibadan Metropolis, Nigeria
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bioRxiv preprint doi: https://doi.org/10.1101/2021.05.18.444309; this version posted May 18, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-ND 4.0 International license. URBANISATION, BIRD SPECIES RICHNESS AND ABUNDANCE WITHIN IBADAN METROPOLIS, NIGERIA 1. Festus O. Adegbola1 (Corresponding Author) Email address: [email protected] 2. Taiye Adeniyi Adeyanju1 Email address: [email protected] 3. Soladoye B. Iwajomo2 Email address: [email protected] 4. Ibukunoluwa Augustine Ayodele1 Email address: [email protected] 1 Department of Wildlife and Ecotourism Management, University of Ibadan, Ibadan, Nigeria 2 Department of Zoology, University of Lagos, Lagos, Nigeria 1 bioRxiv preprint doi: https://doi.org/10.1101/2021.05.18.444309; this version posted May 18, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-ND 4.0 International license. 1 2 3 ABSTRACT 4 Urbanisation is considered as one of the most profound threat to wildlife, with habitat 5 loss and fragmentation being predominant. This study assessed the impacts of urbanisation on 6 richness, abundance of bird species within Ibadan metropolis, Nigeria. A uniform grid of 500 7 square meters was installed on the map of Ibadan Metropolis using QGIS to produce 499 grid 8 points distributed across the five urban local governments. 100 grids were selected randomly, 9 identified with mapinR software application and surveyed with 5 point counts within each gird, 10 established at 200m interval to avoid double counting. Each point count was observed for 5 11 minutes using a pair of 8x42mm binoculars within a 50m radius. Habitat variables like number 12 of buildings, trees, paved roads, communication masts were also recorded. 13 A total number of 56 species of birds were observed at the end of the assessment, classified into 14 30 families. The test of statistics showed that there was no statistically significant difference in 15 bird species richness between the Local Governments. The test of statistics showed that there 16 was no statistically significant difference in bird species abundance between the local 17 governments. The test of between-subjects effects revealed that there were no statistical 18 significant effects when all the habitat variables were computed in the model on species richness. 19 The number of paved roads and number of vehicles showed a significant effect on bird species 20 abundance while others variables in the model did not exact statistically significant effects on 21 bird species abundance. 22 The study therefore concluded that habitat actions due to urbanisation have not affected the 23 richness and abundance of birds species found in all the local governments. The only habitat 24 variables that have currently exacted significant effect on species abundance within the 25 metropolis are number of vehicles and paved roads. Word Count: 292 Keywords: Conservation, Species richness, Species abundance, Urbanisation 2 bioRxiv preprint doi: https://doi.org/10.1101/2021.05.18.444309; this version posted May 18, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-ND 4.0 International license. 26 INTRODUCTION 27 In wildlife conservation and management, there is need for a thorough understanding of the 28 relationships among individual organisms and their environment, as it is important in the 29 development of ecological theories and in the implementation of conservation strategies (Walker 30 et al. 2008). It is general knowledge among environmentalists that there is an increase in the 31 proportion of the earth’s surface now converted to human-dominated urban areas; it therefore 32 becomes expedient to understand how urban wildlife communities within these now 33 sophisticated ecosystem types are structured (McKinney 2002). The importance of understanding 34 the ecological effects of urbanisation cannot be under-emphasised, especially with its rapid 35 conversion of previously wild lands around the world. The process associated with urbanisation 36 has profound effects on the distribution of wildlife species and their habitats (Wolff et al. 2018). 37 Urban development is characterised by rapid population growth and profound land use 38 transformation, leading to land conversion, which is a predominant process affecting ecological 39 community structure and population dynamics of living organisms (Hostetler 1997). Research 40 studies show that urban landscapes supports biotic communities in which only a few species 41 increase in density compared to natural areas, resulting in a distinct difference the community 42 diversity between these two landscapes (McKinney 2002). 43 Developing countries have a large number of wildlife existing outside the protected areas, on 44 farmlands, and in urban areas. Among all wildlife, bird species are largely one of the most 45 common wildlife surviving in urban communities (Gatesire et al. 2015). Birds are one of the 46 most easily studied taxa occurring in cities worldwide as they serve as indicators variables in 47 ecological assessment and monitoring (Magle et al. 2012). Birds are also important in 48 maintaining ecosystems. For example, insectivorous bird species regulate disease vectors 49 including mosquito and rodents. Pied Crow (Corvus albus), contributes to biomass recycling and 50 reduce levels of disposable waste as scavengers. Frugivorous birds play a crucial role in the 51 dispersal of seeds of fruit trees. Sun birds also helps to pollinate plants (Gatesire et al. 2015). 52 Studies show that bird species in different regions respond to urbanisation in a similar way with 53 most research suggesting that bird communities are negatively impacted by urbanisation (Lin et 54 al. 2011; Sol et al. 2014). There is a general shrinkage in species distribution as urbanisation 55 increases, and the fact that similar bird species can be found in various urban landscape indicates 3 bioRxiv preprint doi: https://doi.org/10.1101/2021.05.18.444309; this version posted May 18, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-ND 4.0 International license. 56 that urbanisation has a similar effect on local communities of birds irrespective of the region (Lin 57 et al. 2011). As a result of the crucial role birds play in maintaining ecosystems and also support 58 biodiversity, conservationists seek their protection against biological threats and protect the 59 environment efficiently (Gatesire et al. 2015). 60 Primarily the development level, habitat diversity, age and diversity of vegetation present 61 determine the richness of birds in urban areas (McKinney 2002). Native bird species that persists 62 in urban landscapes partly depends on the actions of the landowners because the structural and 63 vegetative characteristics of urban landscapes are largely human-influenced (McCaffrey and 64 Mannan 2012). Urban areas have less assembly of bird species than adjacent natural areas, 65 though some type and level of development support more native bird species than others. 66 According to McKinney (2002), the moderate level of development and vegetation linkable to 67 low density residential areas can support higher densities of some native birds species than other 68 types of urban land use, also including undisturbed sites. 4 bioRxiv preprint doi: https://doi.org/10.1101/2021.05.18.444309; this version posted May 18, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-ND 4.0 International license. 69 MATERIALS AND METHODS 70 STUDY AREA 71 The study was conducted in Ibadan metropolis, the capital of Oyo State. Ibadan metropolis, 72 covering an area of 129.65 km2 , is located in South-Western Nigeria in the southeastern part 73 of Oyo State at about 119 kilometers (74 miles) northeast of Lagos and 120 kilometers (75 miles) 74 east of the Nigerian international border with the Republic of Benin (Popoola and Wahab 2018). 75 Ibadan falls totally within the forest zone but close to the boundary between the forest and the ◦ ◦ ◦ ◦ 76 derived savanna. It lies between latitude 3 3′ N and 4 10′ N and longitude 7 2′E and 7 40′ E. 77 (Popoola and Wahab 2018). The population of Metropolitan Ibadan is 1 338 659 according to 78 census results for 2006 (Areola and Ikporukpo 2018). There are eleven (11) local governments in 79 Ibadan Metropolitan area consisting of five urban local governments and six semi-urban local 80 governments. The former are: Ibadan South East, Ibadan North East, Ibadan North West, Ibadan 81 South West and Ibadan North Local Government Areas. Ibadan North Local Government has the 82 largest land area among the urban Local Governments, while Ibadan North West is the smallest 83 (Fig. 2). The second largest local government in Urban Ibadan is Ibadan South West. Ibadan 84 metropolis is an important commercial centre and it comprises of people of different cultural and 85 socio-economic backgrounds. General land use pattern of the Ibadan metropolitan area shows a 86 clear distinction purely residential use for Urban Ibadan and agricultural use for semi-urban 87 Ibadan (Salami et al. 2016). 5 bioRxiv preprint doi: https://doi.org/10.1101/2021.05.18.444309; this version posted May 18, 2021.