Water depth, vegetation height, and offshore distance are critical
factors in nest-site selection for Grey Crowned Crane at Lake Ol'
Grey Crowned Crane Balearica regulorum is described as an icon of
Africa’s wetlands and grasslands and is listed as Endangered on the IUCN
Red List of Threatened species. Conservation efforts are partially
hindered by lack of information on factors influencing breeding
productivity, such as nest-site selection. Factors influencing nest-site
selection were investigated at Lake Ol’ Bolossat, a 43.3 km2 wetland
located in the central Kenya from 30 paired nests. Generalized Linear
Mixed-Effects Models were used to analyse the relationship between
factors influencing nest-site selection by cranes and variables that
were predicted to have a compelling influence on nest-site selection
besides i) food and nesting materials availability i.e. the offshore
distance of the nest and water depth, and ii) nest concealment and
susceptibility to predation i.e. vegetation height and grazing
intensity. Results show that variables which had a significant influence
on nest-site selection were: water depth (p=0.005), the offshore
distance from the nest (p=0.037), and vegetation height (p=0.035).
Cranes located their nests in water points above 50 cm deep, vegetation
height of 60-90 cm, and preferably 100 m offshore. A minimum of 103
territorial pairs, both breeding and non-breeding cranes, were recorded.
The middle section of the lake had the highest number (52), while north
and south had 32 and 19 pairs respectively. The mean distance between
any two pairs was 302.53±17.02 (SE) meters. This study sheds some light
on the understanding of characteristics of Grey Crowned Crane’s nesting
sites that will facilitate manipulation and management of breeding
sites. Lake Ol’ Bolossat is consequently a critical breeding site with a
substantial role in the species’ population recovery and survival. A
wetland management option that aims at achieving sustainable use of
lake’s resources by local communities without compromising needs of
wildlife is highly commended.