269
SHORT COMMUNICATIONS
ORNITOLOGIA NEOTROPICAL 14: 269–273, 2003
© The Neotropical Ornithological Society
A SURVEY OF PERUVIAN TORRENT DUCKS (MERGANETTA
ARMATA LEUCOGENIS) ON TWO RIVERS IN PERU
Nancy L. Staus
1
& Eugene F. Weast
2
1
Conservation Biology Institute, 260 SW Madison Avenue, Suite 106, Corvallis, OR 97333,
USA. E-mail: nstaus@consbio.org
2
991 NW Sycamore Avenue, Corvallis, OR 97330, USA.
Reconocimiento del Pato Correntino Peruano (Merganetta armata leucogenis) en dos ríos del
Perú.
Key words: Merganetta armata leucogenis, Peru, Peruvian Torrent Duck, survey.
INTRODUCTION
The Torrent Duck (Merganetta armata) occu-
pies a large geographic range in the Andean
highlands of South America, extending from
Venezuela down to southern Chile (Callaghan
1998). One of only four species of anatid river
specialists that exhibit year-round territoriality
and long term pair bonds (Elridge 1986), the
Torrent Duck is ecologically limited to torren-
tial mountain streams at elevations generally
greater than 1500 m (Johnsgard 1966).
Torrent Ducks in the subspecies Mer-
ganetta armata leucogenis are found throughout
Peru, Bolivia and Ecuador and are considered
vulnerable by the Threatened Waterfowl Spe-
cialist Group (in prep.). Due to the birds’
scattered distribution and secretive manner,
systematic population surveys are lacking and
the Torrent Duck remains one of the least
known species in the family Anatidae. Base-
line information about population density
and distribution is vital for successful detec-
tion of changes in population over time, and
thus for directing conservation management
of the species.
We conducted surveys for Peruvian Tor-
rent Ducks on portions of two rivers in two
major drainage systems in northern and
southern Peru. Our objectives were to (1)
locate river stretches that are used by Peru-
vian Torrent Ducks as potential sites for
future study; and (2) establish new baseline
numbers for monitoring population trends in
the future.
STUDY AREA
There are three major drainage systems in
Peru. To the west of the Andes, rivers drain to
the Pacific Ocean, to the east of the Andes
they drain to the Amazon river (which drains
to the Atlantic Ocean), and rivers in the
southern part of the Andes drain to Lake Titi-
caca. We chose to survey rivers in two of
these drainage systems by their ease of access,
suitability for Torrent Ducks, and proximity
to areas that have been previously surveyed.