“It is almost like a world record," said ecology professor Åke Lindström at Lund University, to the Expressen daily.
The three birds were Great Snipes, indigenous to north Eastern Europe and north Western Russia.
They started their autumn migration from lake Ånnsjön near the popular Swedish ski resort Åre, in August 2009.
Their journey went through half of Sweden, through mainland Europe, the Sahara desert and was concluded in Nigeria in West Africa.
The snipes did the journey without a break. It took them between two and a half and three days.
According to the scientists who tracked the birds there is no other known case of any other animal travelling as rapidly over such a long distance.
They are specifically interested in the fact that the birds chose not to stop and break their journey despite there being plenty of opportunity on the way down over Europe.
Scientists think it could have something to do with fear of predators that the birds chose not to break their journey.
“This means that we will seriously have to question the ideas we had of what these birds are capable of,“ Lindström said.
After a stopover in Nigeria, the three birds decided to continue to the rainforests of the Congo, which came as a surprise to the scientists.
“We didn't expect the Congo at all. It will be exciting to see what they get up to there,” Lindström told Expressen.
After 6-7 weeks in the rainforest, the snipes made their return journey.
This time they stopped for a break in the Balkans and found their way back to Sweden in May 2010.
According to Lindström, the snipes tend to lie low and rest after their return.
“They hardly ever fly,“ Lindström told Expressen.
The report was published on Wednesday in the online version of biology publication Biology Letters.