Ecology of the reproduction of Dendrocygna viduata Linnaeus, 1766 in the Niger River valley

Abstract

The study is undertaken on the sites of Ayérou, Kandadji and Kokorou where still a significant population of Dendrocygna viduata remains. The objective of this study is to include/understand the ecology of the reproduction (measurable and no measurable parameter) of widowed Dendrocygne in the valley of the Niger River, in order to capitalize knowledge for a durable ecological management of this species and its habitat.  Methodology applied consists initially with the systematic research of the nests on the sites.  Then, L be detected nests will be numbered by a  numerical code alpha by order of localized detection then using a GPS, the position and various data will be collected such as the number of egg, vegetation observed around the nests (species, height, covering %), the internal and external diameter of the nest.  In end, the eggs will be measured individually, length (l) and the width (l) will be measured by using a slide caliper. The volume of eggs (v) will be calculated by using the formula of Hoyt.  This like on the three (3) sites, 47 nests are identified  including 14 nests with Ayérou, 13 nests with Kandadji and 20 nests with Kokorou. The average external diameter on the whole of nests is of 26.34cm and the diameter interns’ average is of 18.5çm. On the whole, 347 eggs are laid in the whole of the nests with a rate of reproduction is 50% with Ayérou, 46.15% with Kandadji and 45% with Kokorou.

Keywords:  Ecology, biology, reproduction, Niger River, dam Kandadji