Thursday, October 30, 2008

Longest Non-Stop Flight
Imagine you are taking a plane from Alaska to New Zealand. Now imagine that you are told you have to ride a stationary bike for the entire trip, oh and you can't eat or drink anything. Surely no human could ever prefform this feat, but the bar-tailed godwit could. The bar-tailed godwit live in New Zealand and in Australia and in March of each year they start migrating across the Pacific Ocean towards China, and eventually to Alaska. It had previously been believed that the godwits return flight home was nonstop from Alaska, all the way back to New Zealand because of the lack of bird sightings in Asia in the fall. Recently, satellite tags were placed on several of the birds, finally revealing the flight patterns. Some birds are able to make the 7,200 mile trip nonstop from Alaska to New Zealand. One bird, named E7, completed this journey in only 8 days.

Not much information was given on how the birds are able to navigate across the pacific ocean, and the birds are somehow able to coordinate their departure with the low pressure systems which give them some lift. So why would these birds choose to fly straight home without any breaks? It is thought that the birds do this to avoid predators, and possibly avoid disease. Also, the more direct route is faster. There must be some reason that the birds have evolved to migrate the way that they do, and it seems that only the birds whose genes are fit enough to make the migration would be passed on. While the godwits are in Alaska in the summer, they hatch and raise their young and fatten up on clams. The birds are said to gain so much weight that they look boxy when they leave for their trip home. Also, because the birds don't use their guts to feed during the flight, their guts shrink to allow more room for fat and muscle. I think it is amazing that the birds can even make the migration up to Alaska and still have enough energy and fat reserves to be able to rear and raise chicks.

Bar-tailed godwits mature at age three or four and can live to be over 20 years old. These birds are also quite small, weighing 200-400g with a wingspan of 70-80 cm. The study is done by the USGS along with many other scientists around the world. The migration tracks can be found on the USGS website.


Most Godwits will fly nonstop on their return migration, but a few who cannot make the journey are known to stop in the Solomon Islands and Papua New Guinea. It seems to be more advantageous for the birds to fly non-stop as they can avoid predators and diseases from making unsheduled stops along the way. Stopping to refuel would also be out of their way and could cause them to expend even more energy searching for food. The birds spend the winter in New Zealand where there are very little predators and they migrate to the Kuskokwim Delta, the largest in the world, near Alaska where there is a rich food supply. The death rate is unknown, but it is believed to be low as the population of 100,000 Godwits has been stable.

The birds leave in late August for their migration north, and return in late September, always departing with favorable tail winds. I couldn't find any information on how fast the birds fly, but I did out the math. If a godwit can fly 7,200 miles in 8 days, then that means it was flying 37.5 miles/hour! This seemed fast to me, although they are catching the tail winds, so this might help to give them a lift.

I would also thing the birds would be too full to fly on such a full belly, but somehow they do it. I wonder how the birds evolved this way, and even knew that there was food so far north in the first place to decide to fly so far. I think they're a facinating little bird. I found the answers to some of your questions here.

Posted by: Rachel Carboni(7)


At 10:19 AM, Anonymous Anonymous said...

The godwits return flight home is during the fall. Do they migrate back at a specific month every year? Since, in March of each year they start migrating across the Pacific Ocean towards China, and eventually to Alaska.

Do the bar-tailed godwits that live in Australia migrate directly from Alaska to Australia?


At 5:12 PM, Anonymous Anonymous said...

I really liked the way you wrote this article. The words and descriptions you used made it enjoyable to read. These really do sound like incredible birds!
You said that some of them fly nonstop. What are the other migration patterns seen? Do some of them make stops?

-Cecelia Hunt

At 9:22 PM, Blogger PWH said...

This is incredible. I always find it funny how small animals can withstand more than us, huge and complex humans. At first I was in shock that they could even make this trip, but then you add that they are fat off of clams before they start their journey home, this surprises me even more. Isn't it harder for them to fly such a long distance with all that weight? Also, do they eat so much before leaving so they don't have to eat anything on the way?

Chantal Gomes

At 10:53 AM, Blogger PWH said...

wow! in only 8 days? I wonder at what speed this birds are flying. Have you found any information as to how fast they can fly.

At 10:53 AM, Blogger PWH said...

wow! in only 8 days? I wonder at what speed this birds are flying. Have you found any information as to how fast they can fly.

Jennifer Smith(7)

At 3:55 PM, Anonymous Anonymous said...

I'm curious to know how they can travel so far without any consumption of food or water?

- David Huynh

At 7:39 PM, Anonymous Anonymous said...

Incredible to think what the first step of this migrating behavior might have been. What adaptation began this complex process of traveling thousands of kilometers for breeding purposes?

Allan Eldridge

At 9:00 PM, Blogger PWH said...

To fly that distance is amazing. I never would have thought a bird could fly that long or far. Do the majority of the birds make the trip or does a certain percentage normally die? Have they done any studies on the amount of weight or the amount of calories the bird loses during the trip?

Rob Lubenow

At 11:04 PM, Anonymous Anonymous said...

wow this is a very interesting article. i still cant believe that this is possible.

-Matthew Sousa

At 11:27 PM, Blogger Dan said...

Wow that's shocking. It was mentioned that those fit enough will pass on their genes, i'd imagine not all of the birds would make it. What's the success rate of the birds making the trip?

~Dan Hong


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