Pop quiz: what is brown and grey, gets easily spooked, and connects New Zealand, China and Alaska? While it’s entirely possible that other things fit under that description, the answer we’re looking for is the much-loved Eastern bar-tailed godwit.
Also known as the kuaka, this incredible bird undertakes an annual feat of endurance that will make your daily Covid-19 workout pale by comparison. Every September and October, the godwits, including four-month old fledglings, take off from Alaska when the winds are right, and fly the 12,000 km journey to New Zealand non-stop. That’s right – no inflight meals, no seat-snoozing, no inflight movies for 9 days, and no gliding either as this wastes energy regaining height. Only the Arctic tern flies further, from Antarctica to the Arctic. Godwits spend the New Zealand summer in two locations in the Hauraki Gulf Marine Park/Ko te Pātaka kai o Tīkapa Moana: the Waitematā Harbour (on a daily commute from Manukau Harbour), and on the gleaming white shell banks of the Firth of Thames at the Park’s southernmost point. Known as cheniers, these shell banks have built up over the last 4,500 years to form the basis of a rich ecosystem abundant with food for tens of thousands of shorebirds. The New Zealand population of 85,000 godwits (global population is 330,000) is fully protected.
On arrival, the birds take a well-deserved nap and then get stuck into eating to replenish their reserves. They feed mostly on polychaete worms (sea worms). During their 6-month stay on our shores they will also moult in preparation for their journey back to Alaska to breed.
Apart from around 300 juveniles who aren’t yet breeding, godwits begin to peel off in groups of five to 25 over a 6-week period for their return journey to Alaska. Starting in March each year, the difference in this ‘return flight’ is that they stop-over to refuel in wetlands and estuarine areas of the Yellow Sea region of China for approximately 5 weeks. The route is known as the East Asian Australasian Flyway. Sadly, it here that godwits run into problems, due to extensive habitat loss in the region, which has caused their population to decline annually by 2%.
Progress is being made in the Yellow Sea region however, with two milestones reached just last year. The first was an agreement between DOC and the State Forestry Administration and Grassland Administration of China to work together to protect, manage and restore these wetlands. Also, UNESCO’s World Heritage Committee agreed that parts of China’s Yellow Sea and the sanctuaries it provides for migratory birds will become a World Heritage site giving the birds the protection they need.
Yes, your maths is correct – the godwits are currently on their journey back to Alaska. What’s more, you can track 20 of them on this map, which were fitted with GPS satellite tags while at Pūkorokoro Miranda in November. Sixteen of them were tracked to the Yellow Sea region, and 3 of those have already arrived in Alaska. One godwit took a circuitous route via southern Alaska before heading up to the Yukon Kuskokwim Delta, which would have been its original destination. This detour was caused by a system of northerly winds that forced the bird onto a more easterly track, before getting more suitable conditions allowing it to get back to normal.
Once the godwits arrive on the tundra on the western rim of Alaska, they gorge themselves on cranefly larvae and other invertebrates that become abundant as the permafrost melts. After they are settled, they lay a clutch of four eggs in a shallow bowl, each of which weigh a whopping 11% of a female’s body mass. This means that the chicks are fully developed and mobile at hatching, only taking 28-30 days to fledge. Parents share incubation and brooding post-hatching, but one parent may depart earlier on the long trip back to New Zealand.
More than 4000 of them enjoy the warm months of New Zealand locally. If you’re planning your own epic journey, time your trip in to see the arrival (generally mid-October) or departure (generally mid-March) of these incredible birds at Pūkorokoro Miranda Shorebird Centre. It is a sight to behold.
If you want to help the Eastern bar-tailed godwit/kuaka, consider doing one of the following:
- Participate in Birds New Zealand biannual wader count
- Support Pūkorokoro Miranda Natualists Trust in their shorebird work.
- Volunteer at your local Estuary Care Group.
- Stay off high tide roost sites.
- Don’t allow your dog to chase godwits.
The Hauraki Gulf Marine Park celebrated its 20th birthday this year. It is our first, and only, national park of the sea. At 1.2 million hectares, or 20 times the size of Lake Taupō, it includes the Waitematā Harbour, Gulf Islands, Firth of Thames and the east coast of the Coromandel Peninsula. The Park protects a richness and variety of species and habitats found nowhere else on this planet and was established to help stem the ecological decline of the big blue backyard of the Auckland and Waikato regions. The 2020 State of the Gulf report shows that nitrogen concentrations have increased in the Firth of Thames between 1998 and 2013, with signs that this is lowering oxygen levels in bottom waters of the Firth, making the water more acidic.
Love it, restore it, protect it.