In the process of the adaptation of species to the changing environment and to climate change, an important factor seems to be their ability to disperse. Experts in the related field of ecology have long suspected that migratory birds might be instrumental in transporting living organisms over long distances. Today, we are already aware of the fact that birds may carry viruses that can represent a hazard even to human beings, yet their role in this kind of dispersal has been underestimated up until quite recently.
“For a long time, the general belief has been that the important part of the process is mud stuck to the birds’ feet or grains appended to their plumage. However, it seems that the grains swallowed by them can successfully “survive” the journey through their alimentary canal,” said Attila V. Molnár, a professor at Department of Botany of the Faculty of Science and Technology.
Researchers at this department (including Ádám Lovas-Kiss, Balázs Vizi, Orsolya Vincze, and Attila V. Molnár) collected fecal samples from mallards Anas platyrhynchos, out of which a total of 21 diaspores were identified, of which 8 germinated. One such taxon was the floating watermoss Salvinia natans, providing us with the very first proof in the world about the fact that even aquatic ferns can be dispersed by endozoochory.
“It needs to be emphasized that water birds can disperse not only aquatic but also terrestrial species. Thus, they may be instrumental in the long-distance dispersal of several species that normally travel shorter distances through wind dispersal (anemochory) or dispersal through water (hydrochory). As the grains can spend as long as 1 or 2 days inside the birds, they can travel as far as a thousand kilometers or even farther during this time,” said Attila V. Molnár.
All this can carry serious economic consequences as well: as the allochtonous species carried by human beings from one continent to another may cause substantial economic damage (like, for example, loss of production, pollen allergy, etc.). The aquatic fern Salvinia natans, for example, was transported to the Americas by people from the Old World, while the common ragweed Ambrosia artemisiifolia was brought to Europe from the Americas. When these plants make it across the ocean, their dispersal from that point onwards can be significantly facilitated by various birds.
The full text of the article is available at the homegpage of Journal of Ecology.
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