12 June 2014 Last updated at 12:11
By Zoe Gough
Reporter, BBC Nature
Birds migrating between the Arctic and South America could be responsible for distributing plants across the tropics, according to new research.
Scientists screened wild shorebirds' feathers before migration and found plant parts embedded.
Birds are known to disperse seeds and small animals across local, regional and continental ranges.
It is the first evidence of plant fragments being carried in the plumage of long-distance migratory birds.
A team of ten biologists captured birds at their arctic breeding grounds and examined their breast feathers under a microscope.
Their findings are reported in the journal PeerJ.
They found 23 plant fragments trapped in the feathers of seven of the birds.
The plant parts were all thought to be able to grow into new plants, therefore suggesting they could establish new populations.
If the findings are applied to entire populations of migratory birds, potentially hundreds of thousands of plant parts may be being transported across the equator every year.