My name is Gerrit Vyn and I’m a cinematographer
and photographer for the Cornell Lab of Ornithology. Much of my work over the last 10 years or
so has focused on shorebirds. To film or photograph or record these birds
you really need to know their natural history and their lifecycle because they’re at different
places doing different things at very specific times of the year. One of the most interesting parts of their
lifecycle is spent in the far north in the arctic and sub-arctic on the breeding grounds
where they become these very independent territorial birds and they pair up very quickly to take
advantage of the brief arctic summer to raise the next generation. The rest of the year they are in these wheeling
social flocks travelling the globe on long distance migrations. But for this brief time each year their, their
plumage becomes more beautiful, they have these amazing vocalizations and courtship
displays, and they work together as pairs for the purpose of raising their young. Among all these different shorebird species
there is one species, the Spoon-billed Sandpiper, that everyone who is fascinated by shorebirds
wants to see. Historically it’s been one of the hardest
shorebirds to find. They breed in remote areas in Chukotka in
the Russian Far East and winter in isolated places scattered throughout Southeast Asia. In recent years it became very clear that
populations of this species were drastically declining. Thirty years ago there were thousands of Spoon-billed
Sandpipers. Today there are only a few hundred of them
left. Several years ago I was sent to film this
bird on the breeding grounds and I spent several months of the summer up there following these
individuals as they courted and nested. While I was in Russia I also had the chance
to film nesting Red Knots. They are beautiful russet shorebirds, larger
than a Spoon-billed Sandpiper and they are extremely well camouflaged and they rely on
this camouflage to remain undetected during the period when they are sitting on the nest. So they are very hard to find. The song of the male Red Knot displaying over
the tundra is one of the most beautiful sounds I’ve ever heard in the far north. The champion of all these long distance migrants
is the Bar-tailed Godwit. Particularly populations of Bar-tailed Godwits
that nest in Alaska. I filmed them on the breeding grounds on the
Yukon Delta. Both the male and female godwit incubate the
eggs, roughly on 12 hour shifts. I watched a female walk in toward a male cautiously
after flying in from a distance and very gently with this long beak she brushed the feathers
on his back letting him know it was time for him to get up and for her to get on the nest. When you’re witnessing something like this
it is hard not to deeply feel for these birds as individuals. When you see this commitment to their nest
and to their young you develop a strong caring for these birds and an even deeper fascination
for the things that they are able to do. When shorebird chicks hatch they are able
to feed on their own immediately - they are never fed by their parents. At birth they have really well developed legs,
feet and beaks – the most important things for them when it comes to moving around, staying
safe and feeding. And they grow very rapidly. One of the most fascinating things about these
shorebird chicks is that they are not led south by their parents. As soon as the eggs hatch, or shortly there
after, the female migrates south. Leaving the male to care for and lead the
chicks for several weeks before he also departs and heads south. Once these tiny birds can fly and have put
on some fat they will head south on their own. Unlike some other bird species shorebird migration
routes are innate – they aren’t learned from their parents or from other birds – they
are etched into their DNA through tens of thousands of years of evolution. Long distance migrant shorebirds like these
from across eastern Russia and parts of Alaska migrate south, many of them for vast distances,
to winter in the southern hemisphere or tropics through what is collectively known as the
East Asian-Australasian Flyway. A route that several million birds use in
the fall and then again on their return trip north in the spring because it has such reliable
areas for feeding along the way. Most of the individuals for many of these
species go through the Yellow Sea and for many of them it is their only stop on their
northward or southward migration. Thirty-six species of shorebirds in all use
the wetlands and intertidal mudflats around the Yellow Sea during parts of their migration. The sea is bounded by the Koreas to one side
and China to the other side and its vast intertidal mudflats are extremely productive for marine
life. Each year during spring and fall there are
locations where you can see tens of thousands of these shorebirds congregating in predictable
areas where food is abundant year after year. There is one place on earth where you have
a great chance of seeing a Spoon-billed Sandpiper even though there are only a few hundred left
today and that’s the Rudong mudflats in China – 5000 kilometers from the nest that
I filmed in Russia. I went there in the fall as the birds were
moving through during the time of the year when they are fattening up. I was lucky enough to find several individuals
that I was able to film. The most unique thing about a Spoon-billed
Sandpiper is its spoon shaped bill. It primarily forages in the soupiest of mud
where its flattened bill passes easily from side to side and it uses its bill tacitly
to locate food items in the mud. The beak is packed with sensory receptors
that help it quickly locate large prey items like small shrimp and crabs that aren’t
typically a major part of the diet of other shorebirds its size. Many of these shorebird species are specifically
evolved to take advantage of certain types of prey that are seasonally or locally abundant
and you can see this specialization just by looking at their unique beaks. It's easy to look out at mudflats and think
they are all the same and they all contain the same types of organisms but like any shell
fisherman knows you go to the places where you have the best chance of finding the most
food in the shortest amount of time. The coarseness and types of sediment, the
salinity, the currents, and the available nutrients all play a role in determining the
abundance and types of organisms found in the mud – and for the Spoon-billed Sandpiper,
the Rudong mudflats, fed by sediments from the Yangtze River, create the best conditions for the type of organisms they specialize in catching. For certain populations of Red Knots that migrate from the Russian Arctic, unique conditions on the mudflats at Bohai Bay produce the type of food that they specialize in. The Red Knots beak is kind of a mid length beak – they are not probing very deep into the mud or skimming things from the surface but feeling just an inch or so into the mudflat to the depth where small bivalves congregate. And they have an enlarged gizzard that they use to crush shells very efficiently and process them. In the areas favored by Spoon-billed Sandpipers these high densities of small bivalves don’t exist so the Red Knots don’t go there. The Bar-tailed Godwit makes one of the most impressive migratory flights of any bird. They depart Alaska in the fall and make a 7, 8, 9 day non-stop flight over the open Pacific Ocean to New Zealand. What many people don’t know about their migration is that on the way back virtually the entire Alaska population stops at a small area of the Yellow Sea coast at a place called Yalujiang. They’ll spent up to a month there, fattening up again before taking off to make another nonstop flight back to Alaska to breed. At Yalujiang you can see huge flocks, tens of thousands of these godwits, in the spring as they’re moving north. The soft rich sediments there produce an abundance of deep burrowing marine worms and large shellfish and a substrate good for probing. Watching a Bar-tailed Godwit forage with its incredibly long beak – digging very deep into the mud to the point where its head is even getting buried – its amazing to watch how efficient they are at locating these food items at some of these locations. They’re able to locate and swallow many many prey items in a short amount of time. In order to efficiently put on fat and in order to complete their migrations these birds are relying on mudflats with dense food concentrations. Tens of thousands of years of evolution have determined that this place at Yalujiang is the place where they can find the most food in the shortest amount of time. And for the other 36 species of shorebirds that rely on intertidal mudflats and wetlands of the Yellow Sea it is clear that it is not the vast intertidal areas of the Yellow Sea that are critical to bird life but its these very productive areas within the Yellow Sea that these birds are genetically programmed to go to that are critical to their survival. The Yellow Sea is quite literally the hub of this entire flyway. It is the location that many of these bird species and populations of birds depend on to complete their migrations to their wintering areas and then back to their breeding areas. Without this critical location none of this would be possible. These migrants from Alaska, from much of Russia, from Australia, New Zealand, Myanmar, Southeast Asia – they all depend on the Yellow Sea’s enormously productive intertidal mudflats.
