The impact of changing air patterns on bird flight

Photo Credit: Alvaro-Moya-Riffo

The Challenge

Anyone who has travelled on a plane will realise how important wind is for flight: Wind affects the routes that planes take, the flight time and the amount of fuel that planes require.

What the air is doing is every bit as important for birds in flight, whether they are on their daily commute, their annual migration or choosing a location for nesting.  Understanding the many ways that birds are impacted by changing air patterns is hugely important and a challenge to study: Air is invisible and it is almost never still.

The Method

Newly developed techniques have allowed the team to map what the air is doing over fine scales and estimate the particular conditions birds experience as they fly over fields or along cliffs. Simultaneously flight paths can be recorded to reconstruct their every twist and turn. This is helping the team learn about behaviours that have evolved over millions of years, and provide insight into how birds do (or do not) respond to new structures like buildings and infrastructure, that can represent challenges, threats or opportunities for flying animals.

Working with Dr Sergio Lambertucci and his team in Argentina, Dr Emily Shepard and colleagues used electronic tags to reconstruct the fine-scale movements of Andean condors. Designed by Dr Mark Holton (Swansea University), the tags capture data 40 times a second, recording each wingbeat and the heading that birds took as they circled in thermal updrafts or climbed in air deflected upwards by the Andes.

Theoretical work suggests that even when these birds are flapping, they are losing altitude due to a wingspan of 3m. Condors have evolved to become experts at conserving energy by finding sources of rising air to move around without flapping.

Due to difficulties in transmitting data by phone or satellite network a new system was designed to detach the tags from Condor’s as they roosted, and alert the team to their location.  As there aren’t many roads in Patagonia this meant journeying hundreds of miles on horseback, walking through snow, wading across rivers and trudging through volcanic ash to retrieve the tags from a species that can easily cover 300 km in a day and sleep in different roost site each night. 

This was the easy part. Ugo Mellone.

Professor Emily Shepard

The Impact

The teams findings on Andean condors, which were reported in a recent paper showed just how adept these birds are at finding rising air, spending just 1% of their flight time flapping.  They recorded a flight from one bird that travelled over 100 miles without a single wingbeat. 

Their work may provide valuable insights when planning flight paths for unmanned aerial vehicles (UAVs) and drones, in urban landscapes.  In a similar way to birds, these are affected by gusts and turbulence, far more than larger aircraft. Flying at low altitudes in close proximity to terrain and buildings is challenging, as flight control systems have not been developed to cope with complex urban environments. 

Understanding where seabirds nest could also be important for management decisions, allowing people to predict which areas species may return to. This is pertinent for the many species that have experienced dramatic population declines in the last century.

Further Information

United Nations Sustainable Development Goals