1. 1Department of Biological Sciences, The Rivers State University of Science and Technology, P.M.B. 5080, Port Harcourt, Rivers State, Nigeria
2. 2Federal Department of Forestry, Field Office, P.M.B. 51, Port Harcourt, Rivers State, Nigeria
3. 3Institute of Environmental Studies DEMETRA, Via dei Cochi 48/B, 1-00133 Rome, Italy, and Ecology Research Group (FIZV), Calabar, Cross River State, Nigeriavia Olona 7, 1-00198 Rome, Italy