Champions of Flight

Champions of Flight

Michael Habib explains how some amazing birds rack up thousands of frequent flier miles, and how they do it. 

Originally shared by Michael Habib

Distance Champions: how birds fly thousands of miles without stopping

The image below shows tracked migration routes for shearwaters.  A quick glance will show that the distances involved are quite impressive, covering thousands of miles.  As it turns out, quite a number of birds undertake journeys that would make human pilots envious, and in some cases, these journeys are non-stop (i.e. without landing).  The image below comes from here: (from here: http://www.encountersnorth.org/wildexplorer/birdmigration/Shaffer_fig1_Final.jpg

Before we look at how birds manage these distances, here are some records of note:

Total Distance Champions

Arctic Tern: Migration route of about 13,670 mi straight distance.  They cover around 44,000 miles per year, however, as a result of long feeding voyages and a meandering migration path that differs greatly from the straight distance.

Manx Shearwaters: 8,700 mi total migration distance

Non-stop Flight Champions

Blackpoll Warbler: 2,000 miles; at least half of this is non-stop (over water), since they make it in 40-50 hours it is likely that the entire trip is done without landing. Not bad for an animal massing only 12-15 grams.

Eastern Curlews: 4,000 miles non-stop

Bar-tailed godwit: 7,200+ miles non-stop.  This is the current non-stop champion, and has been recorded with repeated telemetry series (see: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2664343/ and http://www.npr.org/templates/story/story.php?storyId=95997182). Note that these birds are continuous flappers, so they are not soaring for this distance.  They also cannot land/launch from open water, so there’s no way for them to stop in route (confirmed with tracking).

They look like this: http://nzbirdsonline.org.nz/sites/all/files/1200670Bar-tailed%20Godwit%20male%20colour_D3S0626-1024web.jpg

Burning the Engine

One of the primary factors involved in long distance migration is something that Colin Pennycuick has termed burning the engine. Before migration, birds eat a lot of extra food and put on a huge amount of fat.  As they fly, migrating birds burn the fat, which makes them lighter.  This means they require less power to continue flying, so they do something quite interesting: they burn some of the muscle.  That is, they burn the engine.  This provides more fuel while simultaneously keeping the birds at a high efficiency ratio of power available to cost of transport (it is more efficient to run a small engine hard than a large engine at partial capacity).  This continues for the whole trip: some fat is burned, then some muscle, and repeat.  The net effect is a 50% loss of body mass for godwits and others, along with an extraordinary long-distance journey.

For more on models of migration, check out Colin’s 2003 paper on Burning the Enginehttp://www.jstor.org/discover/10.2307/3548165?uid=3739560&uid=2&uid=4&uid=3739256&sid=21102728128521

Join the Conversation

3 Comments

Leave a comment

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: