Avian diversity assessment in Maiganga artificial post-mining site wetland, Dadin-kowa and Biu reservoirs, North East Nigeria

Abstract

Wetlands are unique ecosystems that support aquatic/semi-aquatic plants, making them suitable habitats for water dependent bird species, and other fauna. The study was conducted in Maiganga artificial post mining wetland in Gombe State, and two reservoirs in Dadin-Kowa, and Biu in Gombe and Borno States of Nigeria respectively. The aim was to determine the abundance and diversity of avian species in the three sites. Point count census method was used to record avian species during morning and evening hours across the three sites. A total of 5663 individuals from 177 species of birds were recorded. One hundred and twenty two (122) genera, in 55 families and 18 orders were also recorded. More birds were recorded in the morning (968) than in the evening (537) (F(1, 185.969) = 3.685, p< 0.05), supporting the notion that birds are more active in the morning than evenings. Species richness differed significantly across the three sites (F(2, 439.73) = 8.713,p< 0.000). Dadin-Kowa River was the most
species-rich (161), followed by Maiganga (109) and Biu dam (65). The most abundant species with 940 individuals in total, was the White Face Whistling Duck (Dendrocygna viduata); with 609, 188 and 143 individuals in Dadin-Kowa, Maiganga and Biu respectively. With regards to conservation significance, 37 (14.8 %) of AEWA species were recorded. Likewise, Pallied Harrier (Circus macrourus) and Ruff (Calidris pugnax) two Near Threatened species (NT, 3.0), were recorded. The composition of feeding/functional guilds recorded in the study further suggest the ecological significance of these wetlands. The high number of insectivores (N=68; 37.9 %) recorded could benefit farmers greatly with regards to pest control. The results underscore the importance of progressive reclamation of habitats undergoing anthropogenic modification; as Maiganga had more species
compared to the much bigger and older Biu dam. Biu wetland needs a buffer zone to reduce human activities within the area close to the water to foster species richness and abundance in the years to come. Dadin-Kowa Reservoir could be a potential Important Bird Area (IBA), if harnessed .