The bird's somewhat upturned bill gives it a pug-nosed appearance that well befits its impudence and audacity. In spite of the fact that it often becomes a source of considerable annoyance to the ornithologist when he is trying to become acquainted with some wary bird, this Asiatic visitor has a peculiar charm of daring which quickly established it as my favorite tundra shorebird.
Brandt 1942 , Alaska Bird Trails
The “audacity” of the Bar-tailed Godwit, alluded to by many early observers, is characteristic of breeding individuals. Whether nesting near potential predators, attack-mobbing species many times its size, or arbitrarily dive-bombing nonthreatening species during courtship displays, the Bar-tailed Godwit is an active and dynamic member of tundra bird communities from northern Alaska west to Scandinavia. In fact, recent evidence suggests that nest-site selection, mobbing behavior, brood movements, and perhaps even this godwit's geographic distribution may all be mediated by interactions with other species, particularly large shorebirds, that attack-mob predators. A dearth of information concerning Bar-tailed Godwit demographic parameters, however, has thus far precluded anything more than speculation about the adaptive significance of these behaviors. In fact, surprisingly little is known about major aspects of this species' natural history, particularly on the breeding grounds.
In the nonbreeding season, flocks with tens of thousands of individuals can be found at favored sites along temperate, subtropical, and tropical coastlines from Europe and western Africa to New Zealand. Across the vast longitudinal range occupied by this species, several forms have evolved, although the number, geographic limits, and zones of contact of these forms remain to be definitively determined, particularly in Australasia and Beringia.
Perhaps no aspect of the Bar-tailed Godwit's natural history is as compelling as the fall migration of the North American form, Limosa lapponica baueri . After breeding across subarctic and arctic tundra in western and northern Alaska, nearly 100,000 individuals depart from the Bering Sea coast of Alaska in September or early October, many apparently on a nonstop flight to Australia and New Zealand, a distance of 11,000 kilometers. Commensurate with such a lengthy migration, these godwits carry the greatest fat loads of any migrant bird studied to date. Individuals apparently accommodate such prodigious amounts of fat by reducing the size of their digestive apparatus prior to departing on what may be the longest nonstop migration of any bird in the world.
Published data on Bar-tailed Godwit biology in North America are extremely limited. Information includes anecdotal natural history ( Nelson 1887a , Conover 1926 , Brandt 1942 , Bailey 1948 , Gabrielson and Lincoln 1959 ), distribution (most in general avifaunal reviews; e.g., Pitelka 1974 , Kessel and Gibson 1978 , Gill et al. 1981 , Kessel 1989 , Gill and McCaffery 1999 ), habitat and migration ( Gill and Handel 1990 ), brood-rearing behavior ( Lanctot et al. 1995 ), foraging ecology ( McCaffery 1998b ), and Alaskan observations of birds banded on the nonbreeding grounds ( McCaffery and Gill 1999 ). Studies of breeding biology of Palearctic populations are also limited ( Kondratiev 1982 , Byrkjedal et al. 1989 , Larsen and Moldsvor 1992 , Yésou et al. 1992 , Larsen and Grundetjern 1997 ). Studies of L. l. baueri during the nonbreeding period are more extensive and have been recently summarized in Higgins and Davies 1996 ; most concern distribution ( Riegen 1999 , Sagar et al. 1999 ), migration ( Barter and Wang 1990 , Battley 1997 , Wilson and Barter 1998 ), taxonomy and molt (Barter Barter 1989b , Barter 1989a ), and conservation ( Mundkur 1993 ; Barter et al. Barter et al. 1997a , Barter et al. 1997b ). Studies of migration of other races of L. lapponica are more numerous than for L. l. baueri.