Science & Tech · Science & Environment · 4 hrs ago
Wind and rising air can make flying cheaper than swimming
A study of 50 wild bird and bat species found that flying can be the cheapest way to travel when animals use wind and rising air.
Older estimates ranked swimming as cheaper than flying, but they came from tests in still air and controlled settings.
The researchers used tracking data from birds and bats, along with weather data, to estimate how much energy they used per mile.
An Andean condor spent only 0.1% of its travel time flapping, while a similarly heavy trumpeter swan flapped for 99% of its travel time.
As a result, the condor’s estimated energy cost per mile was 79% lower than the swan’s.
Soaring can bring a bird’s travel cost down to that of a fish swimming at the same weight, the study found.
The findings suggest that moving air is a resource flying animals use, so estimates based on still-air tests may miss a major part of how flight works in nature.
A study of wild birds and bats found that wind and rising air can make flying more energy-efficient than swimming.
The researchers estimated energy costs from tracking data covering 50 species, rather than measuring energy use directly.
An Andean condor and a trumpeter swan weigh about the same, but the condor’s cost per mile was 79% lower.
The condor flapped for 0.1% of its travel time, compared with 99% for the swan.
The findings challenge textbook rankings based on experiments in still air.
- Who
- Researchers led by Martina Scacco of the Swiss Federal Research Institute WSL and the Max Planck Institute of Animal Behavior.
- What
- A study found that wind and rising air can make flying the cheapest way for animals to travel.
- When
- Published on 2026-10-16.
- Where
- The study examined wild birds and bats; the specific study locations are Not stated.
- Why
- To estimate the energy cost of travel in real-world conditions, including wind and rising air.
This story does not have two clearly opposing sides.
Tracking data used in the study spanned 17 years.
Radar data added information on 12 size classes of smaller flyers.
Earth.com published its report on the study.
- Species studied
- 50 bird and bat species
- Tracked animals
- 850 birds and bats from 38 species
- Flight segments
- 194,558 straight, purposeful stretches
- Condor’s flapping time
- 0.1% of travel time
- Swan’s flapping time
- 99% of travel time
- Cost difference
- The condor’s cost per mile was 79% lower than the swan’s
What people are saying
The air is not just a backdrop for flying animals; it is a resource they need and use, like food or water.
We boiled the differences down to fuel economy, nature’s equivalent of miles per gallon.
The laboratory rules tell us that condors and swans must have the same energy bill because they have the same body mass. Yet seeing how condors soar and swans flap, we know that clearly there must be a difference.