Nests and nesting sites characteristics of rufous-throated dipper (Cinclus schulzi) in mountain rivers of northwestern Argentina

SARDINA ARAGÓN PN; POLITI, N.; BARQUEZ R.M.

WATERBIRDS (DE LEON SPRINGS, FLA.)

WATERBIRD SOC

Año: 2015 vol. 38 p. 315 - 320

1524-4695

The Rufous-throated Dipper (Cinclus schulzi) is an endemic and threatened bird that inhabits the mountain rivers of southern Yungas of Argentina and Bolivia. This is the rarest and least known species of the genus, in part because of its restricted distribution. The aim of this study is to describe the nests and nest sites of the Rufous-throated Dipper in mountain rivers of northwestern Argentina. Five rivers were surveyed in transects of 3 to 6 km long from 2010 to 2013. The shape, size, substrate, and building material of nests and nest and non-nest characteristics were assessed and compared in plots of 2 by 2 m. A total of 28 nests found revealed that most (22) has a globular shape, are adhered to rocky substrates, and built with moss. Height of nests above the water level (H = 11.74, P = 0.02), slope (H = 8.84, P = 0.03), and watercourse width (H = 15.88, P < 0.01) varied among rivers. Plots at nest sites had significantly higher percentage of emergent rocks (43.57 ± 17.21 vs 28.99 ± 18.35 %, KS = 0.43, P < 0.01), slope (5.75 ± 2.91 vs 4.16 ± 2.40 %, KS = 0.32, P < 0.02), greater number of rapids (1.60 ± 0.91 vs 1.00 ± 0.80 rapids/plot, KS = 0.52, P < 0.01) and pools (1.24 ± 0.66 vs 0.77 ± 0.64 pools/plot, KS = 0.57, P < 0.01), water velocity (1.14 ± 0.23 vs 0.99 ± 0.27 m s -1, KS = 0.28, P < 0.05), river depth (38.99 ± 9.81 vs 32.82 ± 8.63 cm, KS = 0.41, P < 0.01), and narrower watercourse width (24.76 ± 22.02 vs 49.56 ± 31.03 m, KS = 0.49, P < 0.01) than non-nest plots. This study contributes to the understanding of the breeding ecology of the Rufous-throated Dipper, considering that previous records only provide anecdotal evidence. To understand the breeding habitat requirements is a prerequisite to develop conservation action plan for this threatened species