Every autumn, sensible Godwits (Limosa Lapponica Baueri) leave New Zealand as winter approaches and fly somewhere warm with only juveniles and a few birds that arrived too late to pile on sufficient body fat over summer, remaining behind. The migrating Godwits fly 10,300 km to the east and spend a few weeks feeding along the shores of the Yellow Sea. Once they’re refreshed, it’s a 6,500 kilometer flight to the luxury of a summer spent feeding and breeding around the coast in western and northern Alaska. The total Godwit population breeding in Alaska may be as high as 150,000 with about 85 to 100,000 returning to New Zealand each year, although numbers are declining due to climate change and some habitat destruction at stopovers.
Godwits' Intestines Shrink to Save Weight
In Alaska the Godwits will increase their weight by feeding almost non stop during the very long summer days and will gain about 500 grams of fat until almost 55% their body weight is fat. Once the Alaskan autumn looms the Godwits prepare for their remarkable odyssey to New Zealand by undergoing some remarkable physiological changes to their digestive system. Their kidneys, liver and gut shrink by about 25% to offset the weight of the extra fat they are carrying so the Godwits do not exceed the maximum weight for efficient flight.
Godwit Chicks Self Sufficient Almost from Birth
Each female Godwit will raise, on average, three chicks with her partner sharing the incubation. The Godwit chicks are fast learners as soon after hatching they walk, feed and swim, then fly when just four weeks old. In autumn, they too have an 11,000 plus kilometer journey ahead of them, although they don’t necessarily fly with their parents. Instead they seem to be able to navigate non stop across the Pacific Ocean from north to south without parental guidance, steered only by their instinctive GPS.
Prior to departure, the Godwits concentrate in large flocks, on the Yukon-Kukskokwim Delta and further south along Alaska’s convoluted coast, waiting for a northerly storm to propel them southward on their 8 day 11,500 kilometer journey to New Zealand. They fly in small groups, and if they strike it lucky, a strong tail wind might push them almost as far south as Hawaii. There are no stops along the way for these remarkable birds and their journey usually brings them back to exactly where they left New Zealand the previous year.
Godwits Sleep on the Wing
The Godwits, like some other migratory birds and possibly a few other non avian species, such as marine mammals, have the ability to sleep while flying, or in the case of marine mammals, sleep while swimming. This is done by sleeping with half the brain remaining awake in what is called “unihemispheric” sleep that allows one eye to function and the bird to remain alert enough to fly and navigate.
The Bar-Tailed Godwit an Elegant Bird
The Bar-Tailed Godwit, a member of the Sandpiper family, is something of an elegant long legged, but plain looking bird with a light brown speckly top, a white belly, short tail and a long thin beak that has a slight turn up. They are relatively big birds varying between 36 to 50 cm (14 to 20 inches) long and in prime condition, weigh between 500 to 600 grams (17 ½ to 21ounces) with the females being bigger than the males.
Godwits Local Heros
These long range flyers are heroes in the bird world and welcomed back home to New Zealand with “welcome home” ceremonies being held about mid March in Motueka and other of New Zealand’s Godwit summer resorts. One female Godwit was recorded as having flown almost 30,000 km (approx18,600 miles) in one year with an average speed of just under 55 kph (approx 34 mph) with her longest non-stop trip being 11,680 kilometres (approx 7,200 miles).
Motueka Sand Spit and Farewell Spit Renown Wading Bird Habitat
Home to somewhere between 1000 and 2000 Godwits, the Motueka sand spit is internationally renown as a wading bird habitat. The Godwits stay for seven months at Motueka along with a variety of other coastal waders such as Oyster Catchers. They can easily be seen in the low dunes and feeding in the nearby estuaries. The Godwits also roam quite widely around other estuaries at the top of the New Zealand’s South Island including the vast sand flats at Farewell Spit about 70 kilometers away to the north at the very extremity of the South Island.
Farewell Spit, the biggest Godwit habitat, is relatively isolated and access is only allowed by way of a 4WD bus tour that drives along the beach. At any one time, over summer, there may be 10,000 Bar-Tailed Godwits on the sand flats inside the spit. There are 80 square kilometers (approx.1,9800 acres) of mud or sand flats exposed at low tide and the Godwits share this vast feeding ground with about 90 other species of migratory and local birds such as large black Swans, various gulls, Banded Dotterels, Caspian or White Fronted Terns, Knots and Spoonbills.
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