Nettapus – Pygmy geese

Found primarily in the Old World tropics, these birds are a part of the rich tapestry of biodiversity that thrives within these equatorial regions.

The classification of pygmy geese has been a subject of ornithological debate due to their ambiguous phylogenetic relationships. Initially grouped with ‘perching ducks,’ a category now recognized as paraphyletic, Pygmy geese do not fit neatly into the conventional classifications of waterfowl. Paraphyletic groups consist of organisms that share a common ancestor but do not include all the descendant groups. This realization has led to a reassessment of their links with the dabbling ducks of the subfamily Anatinae, which is now questioned.

The complex evolutionary history of pygmy geese is thought to be part of an ancient divergence of waterfowl species that originated on the supercontinent Gondwana. This lineage includes a variety of waterfowl with unclear phylogenetic relationships, which suggests that these birds have a long and independent evolutionary history separate from other duck lineages.

Pygmy geese are characterized by their small bills, which are quite delicate compared to those of larger waterfowl. Their heads are rounded, which, along with their petite bills, gives them a distinctive profile that is easily recognizable. Additionally, they have notably short legs, which are more adapted to their life in the water rather than on land. Despite these traits, they are adept at perching on branches, a behavior that is unusual among waterfowl but common in the perching duck group.

One of the remarkable aspects of Pygmy geese is their nesting behavior. Unlike many waterfowl that build nests on the ground near water, Pygmy geese often nest in tree holes. This arboreal nesting strategy offers protection from numerous ground predators and flooding, which can be particularly beneficial in tropical regions where sudden downpours are common.