Comparison between Mean Concentrations of Heavy Metals in Male and Female Quelea Birds (Quelea quelea) in Gyawana Ecosystem, Adamawa State, Nigeria

Abstract

Heavy metals are natural components of the Earth's crust, and they enter into the biosphere both naturally and as a result of human activities. This study was carried out mainly to compare by sex the concentrations of heavy metals in the Quelea birds (Quelea quelea) in Gyawana Ecosystem, Adamawa State, Nigeria, for a period of twelve months (December 2015 to November, 2016). Quelea birds (Quelea quelea), were collected once every first week of a month from various locations. A total of four hundred and eighty (480) male and female birds were captured in the wild. Their blood and organs were collected by sex. Their liver, flesh and brain which were dried at 105oC individually according to sex and digested with tri-acid mixture (HNO3: HCO4: H2SO4) in the ratio of 10:4:1, respectively. Determination of the heavy metals was done directly on each final solution using a standard method (Buck Scientific 200A Model, Atomic Absorption Spectrophotometer). The results of this study reveals that, the mean concentration of As, Cd, Co, Cu, Ni and Pb; (0.032±0.000 mg/g); (0.031±0.000 mg/g), (0.654±0.013 mg/g); (0.606±0.004 mg/g), (0.646±0.011 mg/g); (0.644±0.010 mg/g), (18.252±0.043 mg/g); (16.888±0.047 mg/g), (0.043±0.000 mg/g); (0.036±0.000 mg/g), (0.825±0.012 mg/g); (0.797±0.012 mg/g), respectively, were higher in female than male Quelea birds. Male birds had a higher mean concentration of Zn (8.780±0.093 mg/g) than female birds, with 8.717±0.092 mg/g. In conclusion, the concentration levels of the heavy metals studied between male and female Quelea birds, female, had higher concentrations of all the heavy metals studied with exception of zinc which was higher in male than female and chromium was not dictated in both sexes. Both male and female Quelea birds of Gyawana Ecosystem are safe for consumption.