Impact of Seasonal Changes on Avifauna Diversity in Nguru Wetland, Yobe State, Nigeria

Abstract

The research on impact of seasonal changes on avifauna diversity in Nguru Lake of Hadejia-Nguru Wetland was carried out in two different seasons for the period of six 6 months, from April to June (dry season) and July to September (wet season). The aim was to evaluate the impact of seasonal changes on avifauna diversity and the species richness in the study area. A reconnaissance survey was carried out to select study sites and sampling points. Five (5) different points were selected which comprises of Madauka, Kayayyashi, Farin Ruwa, Badum and Guzan respectively and Point count census techniques were adopted. In each counting station, bird observation was carried out twice daily; morning between 6:00 am and 10:00 am and evening between 4:00 pm and 6:00 pm. Data compilation was done using Microsoft Excel and were analysed using statistical software Past 326b. Bird diversity was calculated using Shanon-Weiner diversity index. The findings of this research showed that the majority of birds identified were Resident species (12,225 individual birds), Migratory species (8,186 individual birds) and Palearctic Migrants (10,876 individual) species in the study area. Dominant bird species in Nguru lake were Philomachus pugnax, Actophilornis africanus and Phalacrocorax africanus. A total of 5,538 individual birds’ was identified (Dry Season) in Nguru lake ‘’ belonging to 21 families in which Ardeidae family had the highest (7) species of bird. Shannon Diversity Index’ has 2.55 in dry season, while in Wet Season’ has 3.40. This indicated that there was relatively equal and high diversity of bird species in Wet Season in the study area and has the total species richness of 6,711. Overgrazing and other anthropogenic activities which affect the population diversity of avifauna species serve as major threats to the continued existence of Wetlands. Typha grass also remained pressing problem which create microhabitats reducing critical habitat for feeding, nesting and roosting habitat for birds, as well as hampers the smooth flow of water used by many water bird species. In view of the findings of this study, effective monitoring and strategies for conservation to restore the population of bird species, provide public enlightenment of the people around the wetland and management of Hadejia-Nguru Wetland promptly advice the significant importance of the wetland in serving as home for resident and migratory birdspecies.