Project

Torrent Duck

Merganetta armata armata

Scope of the project

Human disturbances and climate change are considered the main threats. Invasive species were also mentioned as a problem. However, we believe that the latter have been underestimated.

habitat and behavior

They inhabit abundant watercourses in the Andes, from Tierra del Fuego to Venezuela. In Argentina there are two breeds, one in Cuyo and Patagonia and the other in the Northwest. They live in pairs and usually maintain the same territory. They have adaptations for the extreme environment where they live, such as large legs, developed musculature, hydrodynamic body and long and rigid tail that serves as a rudder.

feeding

They scrape submerged rocks in fast-flowing rivers to obtain larvae of benthic macroinvertebrates (e.g. insect larvae, such as mayflies).

reproduction

For pair formation, males compete by showing off in front of the female. They nest in high places on the river bank. The nest may be in the hollow of a tree or on a rock ledge. The eggs are large, incubation is carried out by the female (up to 44 days!), the longest among ducks.

curiosity

To feed, it dives in the strong currents and uses a conical and flexible beak, unique among anatidae, which allows it to scrape the rocks to obtain its food.

context

Torrent Duck Project

The Torrent Duck is a charismatic species throughout its distribution, but especially so in Southern Patagonia, as it inhabits areas of great scenic interest and with much recreational use. But also, because it is in Patagonia where the population reduction of the Torrent Duck is very striking, with very striking local extinctions. The discussion about the increasing rarity of the species has led many researchers and specialists from conservation institutions to focus on some of the problems, mainly “chasing” human recreational activities, but without really solid evidence, and at the same time neglecting or underestimating the impact of other threats, such as invasive species. Surely the threats act synergistically, even more so in a context of climate change. This is why we have proposed to know important aspects of the ecology of the species, the real impact of the threats, but also to develop management plans that allow the recovery of their populations.

patagonia in action program

Lines of research

Population and conservation status of the Torrent Duck from Domuyo to Tierra del Fuego.

Responsible

Estefania Micheltorena

State

Active

Target

Define the current distribution of the Torrent Duck and evaluate the conservation status by analyzing the effects and degree of overlap with the main threat factors identified so far. To know the availability of food available to them. The project seeks to generate fundamental information to adapt and maximize the success of the restoration plans carried out in the region.

methodology

The study is carried out in rivers and torrential mountain streams. During the spring-summer months (November-March), we scour rivers and streams to detect individual Torrent Ducks, using binoculars and telescopes to count and identify the birds. At each positive location of Torrent Duck individuals we record the exact GPS point, and additional information about the sighting (e.g. number of individuals, sex, age). We also look for signs of predator presence, such as American Mink tracks and feces. To study the conditions (habitat quality) of the rivers sampled, three points per watershed are defined. The macroinvertebrate sampling points are defined in 1 km sectors, within which 3 samples are obtained at three points (within the defined km). Samples of benthic macroinvertebrate larvae are obtained using the Surber net method (30 x 30 cm). The bed rocks are lifted and cleaned using a brush, in front of the net opening (Cerón 2012). They are collected and fixed in alcohol and then analyzed under a magnifying glass in the laboratory, which are counted and classified following Fernández and Domínguez (2001). The results will be analyzed with generalized linear mixed models in which specific richness, diversity and relative abundance of each species in the different watercourses will be compared. In each transect, in addition to recording environmental variables, data will be collected on the presence and intensity of the previously mentioned threat factors: 1) presence of American mink; 2) presence of anthropogenic activities: artisanal-sport fishing, kayaking, hiking, camping, cattle ranching, and others.

results and progress

From 2019 to the present, we have traveled through most of the flowing streams in the west of the province of Santa Cruz, including sectors of Patagonia NP, Los Glaciares NP and Perito Moreno NP. All population monitoring is complemented with sampling for the presence of threats, aquatic invertebrates, etc. A paper was published in Aves Argentinas Magazine (September 2021) and in 2021 we were awarded the Latin American Bergstrom Awards of the Association of Field Ornithologist (USA). During 2022 we started monitoring in the ANP Domuyo, Neuquén and presented a paper at the Argentine Ornithological Meeting. Since the beginning of the project we have participated in the Torrent Duck census in the Río de las Vueltas basin, which is carried out together with Los Glaciares National Park and the National Parks Administration and ACEN.

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