GPS-tagged toucans solve how seeds spread through rainforests
- By Kevin McCaney
- Aug 01, 2011
Researchers are using Global Positioning System backpacks on toucans to study how seeds are spread through tropical forests. And it turns out that they can wind up pretty far from the tree.
The dispersal of seeds is important to understanding how forests work, “but is hard to study because tracking seeds is difficult,” the researchers, from the Smithsonian Tropical Research Institute in Balboa, Panama, write at ScienceDirect.
So they used a combined high-resolution GPS receiver with a 3D-acceleration bird tracking system attached to toucans that feed on the nutmeg-like Virola noblis in a rainforest in Panama. The toucans process the outer shell of the trees’ seeds and spit out the hard seed inside, the researchers write. The birds are on the move while they're feeding, spitting out seeds after an average of 25.5 minutes.
By tracking the birds’ movements via GPS and modeling their dispersal of seeds, the biologists found that toucans will disperse seeds about 145 meters from the tree, on average. They said that's about twice the distance previously thought.
The researchers also found that the toucans were more active in the morning, suggesting that seeds from fruits that ripen in the morning would be spread farther.
The backpacks attached to the toucans were lightweight aqnd designed to fall off after 10 days, according to Wired.
Kevin McCaney is a former editor of Defense Systems and GCN.