The Andes are massive in every sense of the word.  Their sheer size makes them a haven for biodiversity.  A fine example of this is the beautiful, black and white Andean Goose.

Most geese species are large, rather ungainly birds. To help them overcome these traits they are very social, nesting in loose colonies, favouring wide open spaces where they can easily watch for predators.  For these reasons they often nest in isolated cold temperate zones but have to migrate thousands of miles to find a warmer place to spend the winter.

In the central parts of the Andes the high Puna ecoregion is 3,300m in height, it is isolated and cold, an ideal habitat for the Andean Goose. But the clever Andean Goose doesn’t have far to go for the winter, they just migrate or move  down the spectacular Andes to lower ground.  In the province of Tucuman in the far north of Argentina  we found the birds in the Tafi del Valle area, around the picturesque embalse (reservoir) of El Mollar, which is around 2,000m high.

We camped on the shoreline of the embalse and counted up to 250 Andean Geese in one flock.

In the evening they tended to roost together on the shoreline, but during the day distributed themselves across the rich green alluvial marsh in smaller groups, often in pairs.  Sometimes we observed that one member of a pair was noticeably smaller than its partner and we suspect that the birds kept together in breeding pairs.