Teal ducklings go cuckoo over nature’s own eco-engineer

The results of a newly published study show that common teal ducklings thrive in flowages created by beaver dams. In many areas, the number of beaver ponds is the key factor determining the number of common teal juveniles that are produced each year.

Beavers are nature’s engineers, who use their construction expertise to build huge dams that result in large forest flood pools. Across the entire animal kingdom, just the African elephant can match the power beavers possess to shape their habitat, and together they are the only mammals capable of bringing down whole mature trees.

Leave it to beavers

The study compared two areas in southern Finland; Evo which has a resident beaver population and Nuuksio which does not. The two areas lend themselves particularly well to comparative analysis as they are very similar and both remain relatively untouched by human activity.

The results leave little room for ambiguity, with common teal pairs and broods clearly preferring areas where beavers are present. The researchers speculate that the flightless ducklings thrive in the beaver ponds as they offer a plentiful source of food in the form of insects. Adult common teals are more likely to move between ponds.

Data from just one beaver pond was enough to reveal the common teal ducklings’ preference, while the impact of beaver ponds on the behaviour of adult pairs became apparent upon larger-scale comparisons between beaver and non-beaver landscapes.

Beavering away at wetland restoration

Wetlands are ecological communities characterised by their diversity. They also offer important benefits to humans as they filter out pollutants and other impurities found in water and create habitats for young fish and broods of waterfowl. In the past century, anywhere between 60 and 90 per cent of all European wetlands have been lost, and there is now a huge need for their restoration.

The beaver is ideally suited to this important task: its activities serve to effectively restrict the flow of water and, as a highly adaptable animal, it is capable of adapting to a number of different habitat types – after all, the beaver used to be widespread before land was cleared for human use.

This study supports earlier findings suggesting that beaver reintroduction is an economically and practically viable method for wetland restoration. 

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