Tuesday, 3 September 2013

Knot work

Work trips are not all there are cracked up to be. While Dark-sided Flycatchers call from outside and Eastern Crowned Warblers crash into the window trying to draw attention, we have to sit all day in a room discussing the finer details of Reed Parrotbill diet and Saunders’ Gull nesting requirements as we try to design a 2,500 ha nature reserve. How can we provide more food for Black-faced Spoonbill?

Yesterday however, we did get out early. Wading barefoot through the mudflats of Chongming Dongtan nature reserve, we talked to bird ringers catching waders and local fishermen catching shellfish. The ringers were catching and colour marking waders; with the aim of adding to the knowledge of how waders use the East Asian-Australasian flyway. The catch was mainly Broad-billed Sandpipers, Long-toed and Red-necked Stints. The birds are caught by specialised bird catchers using clap nets with decoys. The fishermen were mainly sifting the bivalve Corbicula out of the mud to try and earn a crust; this beast also being a major food source of the Great Knot. But the introduced Spartina a vigorous grass growing to 2m tall, threatens both the fishermen’s livelihood and the Great Knot. Fishing for shellfish in the reserve seems a bad idea but the shellfish company also sprays out the Spartina that is marching across the mudflats at an alarming rate. The mudflats held Greater and Lesser Sandplover and Grey-tailed Tattlers. All day long birds moved south, calling flocks of Wood Sandpipers, Marsh Sandpipers, Terek Sandpipers, Far Eastern Curlews, Great Knot, and Whimbrel, along with hundreds of White-winged Black Terns, Swallows and Yellow Wagtails. It was okay I suppose.

“What does the ecologist think” stops me daydreaming about yesterday and brings the mind back inside to the theory. One of the reserve’s key species is the Marsh Grassbird, a skulking species with a distribution split into a number of isolated sub-populations across China, Japan and Korea. At Chongming, it is one of the few species found in the Spartina marshes. Can we remove the invasive Spartina without losing Grassbirds? Elsewhere it is found in more varied marshy grasslands including overgrown rice paddies. Breeding birds seem to prefer dense, mid-height reeds and grasses in shallow water for nesting, with some taller plants for singing posts. Now, where shall we create the islands for breeding Saunders’ Gull? Can we grow a sacrificial rice crop to lure the Hooded Cranes off the adjacent farmland? Outside it starts to get dark, the flycatcher rattles off to roost and Night Herons fly past the window. Kwak.

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