Abstract

RAMIREZ U, Laura M; BOTERO B, Álvaro  and  KATTAN, Gustavo. DISTRIBUTION AND ABUNDANCE OF THE TORRENT DUCK Merganetta armata (AVES: ANATIDAE) IN THE QUINDÍO RIVER, COLOMBIA. Bol. Cient. Mus. Hist. Nat. Univ. Caldas [online]. 2014, vol.18, n.2, pp.172-180. ISSN 0123-3068.

The torrent duck (Merganetta armata) inhabits torrential rivers along the Andes mountain range. This habitat specialization makes it vulnerable, reason why it is important to document population densities and their spatial and temporal variations, to understand responses to habitat alterations. The distribution and abundance of the torrent duck in the Quindío River and several small tributaries in the Department of Quindío, Colombia was evaluated in this work. Monthly counts of ducks during eight months (June 2011 to January 2012) were made along 8.5 km of the river. The species is distributed all along the Quindio river bed between 1,415 masl. as far as the junction of the Cárdenas and San José streams at 2,264 masl. and seven of its tributaries. The highest elevation record was at 3,325 masl. Monthly ducks density was negatively correlated with precipitation and varied between 4.1 and 6.8 individuals per km during months of low precipitation, versus less than one bird per km in the rainy months. This drop in density occurs because, when the river is fast-flowing, ducks probably move to other areas, among them to the smaller tributaries in the highest parts of the river. Densities in the Quindío River are high compared to those reported in studies for other places in Colombia, Peru and Argentina. It is necessary to carry out more studies which allow establishing duck movements in relation to the river's flow rate as well as the impact of the flow on the abundance of resources (aquatic insects) and breeding seasons.

Keywords : Colombia; population density; altitudinal distribution; habitat specialization; torrent duck.

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