A study led by the Doñana Biological Station (EBD-CSIC) found that the first step in seed dispersal by waterfowl – seed ingestion – depends on seed availability in the waterfowl foraging habitats. Researchers found that the main gradient found to determine such interactions is related to soil moisture, in line with differences between waterfowl groups in their microhabitat preferences along the land-water continuum

Researchers have found that eggs of two fish species can survive passage through the digestive tract of waterfowl after being swallowed, and this finding may help explain the long-standing mystery of how some species of fish colonize isolated lakes and ponds.

It is well known that some plants and plant fragments can become attached to the feathers of ducks and other waterbirds and be transported short distances. An increasing diversity of plant seeds have also been shown to survive gut passage and to be able to disperse longer distances inside migratory birds. For the first time, this paper shows that entire flowering plants can be dispersed on the inside.