By Liz O’Connell for Frontier Scientists
Early on Bob Gill, Research Wildlife Biologist with the U.S. Geological Survey (USGS), thought Bar-tailed Godwits’ journey from Alaska to New Zealand was a non-stop flight. Faced with skepticism from his colleagues, but armed with satellite technology, Gill tagged a female Godwit he named E-7. By tracking E-7 in 2007, Gill was able to prove that Godwits are airborne from Alaska to New Zealand for a week or more—the longest non-stop migratory flight for any bird.
Scientists are concerned that as development occurs in areas where Godwits-when not flying-molt and refuel, the birds will encounter new obstacles and hazards.
“Tracking Alaska’s Godwits,” is a video produced by the Cornell Lab of Ornithology about how Gill and the USGS crew proved the Godwits’ feat. http://ak.audubon.org/videos/tracking-alaskas-godwits
The timing, routes, flight lengths, and flight durations are detailed for the two Godwit sub-species that inhabit the Pacific Basin in a new article in the Journal of Avian Biology 43:001-012, (2012) titled “Contrasting extreme long-distance migration patterns in bar-tailed godwits Limosa Lapponica” by Battley, et al. Map and tables illustrate the enormous distance traveled.
It has been proved that Godwits fly the longest known non-stop flight of any landbird (Gill et al. 2009), the question remaining is, how do they do it? Explanations can be found in the following journal articles that detail meteorology as well as the Godwit biology as important factors in the Godwits’ ability to go the distance.
- Extreme endurance flights by landbirds crossing the Pacific Ocean: ecological corridor rather than barrier? (Gill, et al. 2009)– Proc. R. Soc. B 276: 447–45.
- Can wind help explain seasonal differences in avian migration speed? (Kemp, et al. 2010)– J. Avian Biol. 41: 672–677.
- Guts don’t fly: small digestive organs in obese bar-tailed godwits. (Piersma and Gill, 1998) – Auk 115: 196–203.
The places where Godwits reside throughout the year include The Firth of Thames and Golden Bay in New Zealand during the Austral summer (November through March); the Yellow Sea where the Godwits Gill has tagged stopped on portions of North Korea, South Korea and China. In Alaska, the Colville River is their breeding area. The Kuskokwim Shoals area in Alaska is a key staging site for southward migration; it functions, as does the Yellow sea, by providing the food to fuel the Godwits’ incredibly long flights.
To find out more about the particular habitat features of stopping points for Godwits check out:
- Invisible connections: why migrating shorebirds need the Yellow Sea. (van de Kam, et al. 2010)– CSIRO Collingwood.
- Stopping vs staging: the difference between a hop and a jump. (Warnock, 2010) – J. Avian Biol. 41: 621–626.