Ornithologists were amazed to discover that a bird as small as a swallow could make a round - ​ trip of 14,000 miles [22,500 km] before returning to the same nest the following spring.
Ornitoloogid olid hämmastunud, saades teada, et nii väike lind nagu pääsuke teeb läbi 22500 - kilomeetrise edasi - tagasi rännu, enne kui ta järgmisel kevadel samasse pesapaika naaseb.