8/6/2019 Poster Cambridge 4

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Species Description

Taxonomy: Torrent Duck. 6 subspeci es.

Distribution: Andes from Venezuela to S Chile/Argentina.

Habitat: Fast flowing mountain waters.

Food : Aquatic invertebrates.Breeding: Enduring pairs, Territorial (1km)

Nest : In holes, river banks. 3-4 eggs.

Life story traits: Long li fe bird, low reproductive potential

Status: Not globally threatened.

2 subspecies : vulnerable & endangeredChile : inadequately known

O'Higgins Region : vulnerable

Threats: erosion by deforestation, water pollution,

competition or predation by non-native animals

hydroelectric activity

Habitat selection by Merganetta armata and its sustainable stream flow

requirements in the headwaters of a Chilean Andean river

Claire Pernollet1,2 & Rodrigo I. Meza3

1 Bioamrica Consultores, 2 Laboratorio de Ecologa de Vida Silvestre, 3 Centro de Ecologa Aplicada

STUDY AREA (MAP) :

1 BASIN, 4 RIVERS

2 old hydro power plants

+ 1 under construction

+ 1 project

PART 1 : Habitat selection model

Ducks monitoring: monthly,74 points2007-2010(Map,Graph1)

Habitat variables: altitude, channel shape, channel & river width,

bank river height, distance to the road, position in relation to the

intake, n of rapids, n of emergent rocks, gradient, flow, velocity

indices, densityof ducks in theadjacent points

STATISTICAL ANALYSIS DUCKS DENSITY (Duck/km) = f(X1+X2+X3+X4) Xi = Habitat variable

RIVERS TOGETHER 1) Generalised Linear Models (Table 1) FOR EACH RIVER 2) Chi-square 2 test & Bonferroni confidence intervals

RESULTS TERRITORIALITY:

Negative effect of the presence of conspecifics in adjacent sites

Territoriality may determine spatial segregation

HUMAN DISTURBANCES:

Negative effect of the two intakes. Avoid the presence of roads

FISICAL ATTRIBUTES:

N of rapids, gradient, position upstream the intake, flow & water velocity:

important attributes in their habitat preferences

PART 2 : Hydraulic model

VELOCITY , DEPTH, REYN OLDS NUMBER*

* Reynolds Number : ratio of

inertial forces to viscous

forces, turbulent flow occursat high Reynolds number.

3) Hydraulic model: calculation values

of velocities, depth and Reynolds

for each profiles.

1) Water level, flow gauge and

bathymetric profiles (Map)

2) Diary flows records associated

withselected ducks points with

high frequency of sightings

5) Adjustments by the Chi-square 2 Test.

2ndCRITERION: 3 limits, exceedance probabilities of

95, 90 and 85 % for each parameter.

STATISTICAL ANALYSIS Frequency distribution of each parameters Ducks sightings

4) Parameters Frequency Distribution

and Ducks density.

1st CRITERION: intervals based on the

ducks sightings (minimum and

optimum values for ducks).

Study financed by:

Study made by:

clairepernollet@hotmail.com

romeza@ing.uchile.cl

Ducks photographs:

Jos Besa

josebesad@hotmail.com

Graph 1: Ducks monitoring Table 1: Example of GLM.

RESULTS

This is a first approach of habitat suitability estimation. On one hand,

duck monitoring was made before the habitat suitability estimation. On

the other hand, data were insufficient to make robust statistic analysis.

Other studies based on the relationships found here between Torrent

Duck habitat preferencesand physical habitat conditions should be carry

out to ensure an sustainable hydroelectric projects development in theChilean Andeanrivers.

Authors emails: