New Zealand is home to some amazing birds. We have endemic species that live nowhere else in the world. We also play host to some migrant species that travel a long, long way to get here. Bar-tailed Godwits (Limosa lapponica), known in Māori as Kuaka, are one of those species. They’re also our 2015 Bird of the Year!
Godwits are some of the most amazing migrators on earth. They’re not the only bird species that traverse great distances in order to feed and mate, but they’re special to New Zealanders. Every spring, Bar-tailed Godwits arrive in their tens of thousands to forage in our rich southern summer. They’ve come all the way from Siberia and Alaska, having bred and raised their chicks in the northern summer on the tundra. Some of the birds that fly have only just fledged, and they make the trip across the Pacific at around four months old! That’s an eight to nine day flight, covering up to 12,000 kilometers, with no stops. Watching their great flocks twist in the air like ribbons is an experience you have to have.
Where can you see Godwits in New Zealand? From early September they start arriving on the mudflats of harbours and estuaries around the country – so that’s a good place to start. After the breeding birds leave in March, non-breeding birds often remain around New Zealand as well. There’s no point in making the long trip if they’re not going to breed, and they only start breeding at four years old. They can be hard to spot as they’re well camouflaged on mudflats, and they’re also very shy birds – so don’t get too close or you’ll scare them away.
Miranda is a great place to see Godwits, as well as many other special shorebirds like our endemic Wrybill, and the Black-billed Gull – the world’s most endangered gull species. The Pukorokoro Miranda Shorebird Centre is full of great information about the birds and their migrations, and you can also stay there if you want to spend some time in the area.
Towards the end of their stay in New Zealand, the males begin to take on their breeding plumage of deep russet red. They start to stand out from the grey-brown females and juveniles that blend so well into the mudflats. Here’s a male (foreground and above) compared to two females (background). You can see the different plumage, and also how the females are larger, with longer beaks. Females need to have enough energy to not only make the huge migration, but also mate and lay eggs at the end of it. That’s a serious job for a bird that only weighs 600g! Before they migrate, Godwits gorge themselves and gain as much weight as possible. This is called hyperphagia – excessive eating – and it builds up their fat and energy stores so that they can fly non-stop. Unlike seabirds, they can’t stop and have a rest or a meal on their way.
Their north-bound migration takes them to the Yellow Sea region in China, before they head back towards the breeding grounds in Alaska and Siberia. This is the East Asian-Australasian Flyway, but there are other populations of Godwits that migrate elsewhere in the world. There are several different subspecies that follow different routes and spend their summers all around the southern hemisphere.
Godwit numbers are threatened mainly by habitat loss as the estuaries and mudflats they rely on for food are developed and ‘reclaimed’. Climate change is also a concern as it further shrinks their breeding habitat on the tundra, and their feeding habitat as mudflats are flooded. Bar-tailed Godwits are listed as “recovering (threatened overseas)”.
The Miranda Naturalists’ Trust is dedicated to “keep the birds coming”, and works with countries along the East Asian-Australasian Flyway to promote the conservation of Godwits and their habitat. Maintaining these vital staging points along the migration route is crucial in keeping these birds alive – if they can’t migrate, they won’t survive to mate. The work that these guys have done in promoting awareness of shorebirds internationally is amazing, and I frequently enjoy attending talks organised by them.
Further Reading:
Woodley, K. 2013. Bar-tailed godwit in Miskelly, C.M. (ed.) New Zealand Birds Online. www.nzbirdsonline.org.nz
http://www.miranda-shorebird.org.nz/
http://www.birdlife.org/datazone/speciesfactsheet.php?id=3005
