Wildfowl & Wetlands Trust (WWT)

This came less than six months after Rich and WWT's Head of Species Conservation Baz Hughes were among the first ever people to capture Brazilian Mergansers for conservation purposes, during a field trip to Brazil's Serra da Canastra National Park.

Little is known about the ecology and habitat use of Brazilian Mergansers. They are known to occur on fast-flowing rivers with adjacent gallery forest, but knowledge of how they use these habitats is poor. Adults are thought to remain on the same territiory all year round, but almost nothing is known about their movements and dispersal, so this currently remains informed speculation.

During September WWT worked with partner Terra Brasilis with the hope to capture and mark with colour rings both ducklings and adults, so that they may be identified again in the future. It was intended that six of these birds will also be fitted with radio tags, so that detailed information on their habitat use can be collected.

See how Rich got on during his expedition to Brazil, by reading his regular blog.

Critically endangered

Brazilian Mergansers are one of just six species of wildfowl to be considered Critically Endangered on the World Conservation Union Red List. They are extremely sensitive to habitat loss and disturbance caused by factors such as logging, river siltation, mining and tourism. Numbers are believed to have decreased in recent decades, but information on historical numbers is lacking.

There are currently around 100-150 Brazilian Mergansers known to exist in the wild, almost all in Brazil. Small numbers also remain in Argentina, but the species has not been observed in Paraguay for around 25 years. However, the total population is likely to be larger (around 250-300) as there are a number of areas holding suitable habitat that have yet to be surveyed. Nevertheless, the species remains critically endangered, pareticularly as there is currently none in captivity.