Massive seawall construction in coastal wetlands threatens biodiversity

Summary1. There is increasing concern about the world's animal migrations. With many land-use and climatological changes occurring simultaneously, pinning down the causes of large-scale conservation problems requires sophisticated and data-intensive approaches. 2. Declining shorebird numbers along the East Asian-Australasian Flyway, in combination with data on habitat loss along the Yellow Sea (where these birds refuel during long-distance migrations), indicate a flyway under threat. 3. If habitat loss at staging areas indeed leads to flyway-wide bird losses, we would predict that: (i) decreases in survival only occur during the season that birds use the Yellow Sea, and (ii) decreases in survival occur in migrants that share a reliance on the vanishing intertidal flats along the Yellow Sea, even if ecologically distinct and using different breeding grounds. 4. Monitored from 2006-2013, we analysed seasonal apparent survival patterns of three shorebird species with non-overlapping Arctic breeding areas and considerable differences in foraging ecology, but a shared use of both north-west Australian non-breeding grounds and the Yellow Sea coasts to refuel during northward and southward migrations (red knot Calidris canutus piersmai, great knot Calidris tenuirostris, bar-tailed godwit Limosa lapponica menzbieri). Distinguishing two three-month non-breeding periods and a six-month migration and breeding period, and analysing survival of the three species and the three seasons in a single model, we statistically evaluated differences at both the species and season levels. 5. Whereas apparent survival remained high in north-west Australia, during the time away from the non-breeding grounds survival in all three species began to decline in 2011, having lost 20 percentage points by 2012. By 2012 annual apparent survival had become as low as 0Á71 in bar-tailed godwits, 0Á68 in great knots and 0Á67 in red knots. In a separate analysis for red knots, no mortality occurred during the migration from Australia to China. In the summers of low summer survival, weather conditions were benign in the Arctic breeding areas. 6. We argue that rapid seashore habitat loss in the Yellow Sea is the most likely explanation of reduced summer survival, with dire (but uncertain) forecasts for the future of these flyway populations. This interpretation is consistent with recent findings of declining shorebird numbers at seemingly intact southern non-breeding sites. 2016, 53, 479-490 doi: 10.1111/1365-2664.12582 7. Policy implications. Due to established economic interests, governments are usually reluctant to act for conservation, unless unambiguous evidence for particular cause-effect chains is apparent. This study adds to an increasing body of evidence that habitat loss along the Yellow Sea shores explains the widespread declines in shorebird numbers along the East Asian-Australasian Flyway and threatens the long-term prospects of several long-distance migrating species. To halt further losses, the clearance of coastal intertidal habita...

SummaryThe coast of Bohai Bay, north-western Yellow Sea, is critical for waterbirds migrating along the East Asia-Australasian Flyway. Between 1994 and 2010, a total of 450 km 2 of offshore area, including 218 km 2 of intertidal flats (one third of the original tidal area in the bay), has been reclaimed along the bay for two industrial projects. This has caused the northward migrants to become concentrated in an ever smaller remaining area, our core study site. The spring peak numbers of two Red Knot subspecies in the East Asia-Australasian Flyway, Calidris canutus piersmai and C. c. rogersi, in this so far little affected area increased from 13% in 2007 to 62% in 2010 of the global populations; the spring peak numbers of Curlew Sandpiper C. ferruginea increased from 3% in 2007 to 23% in 2010 of the flyway population. The decline in the extent of intertidal mudflats also affected Relict Gulls Larus relictus, listed by IUCN as 'Vulnerable'; during normal winters 56% of the global population moved from the wintering habitats that were removed in Tianjin to the relatively intact areas around Tangshan. Densities of wintering Eurasian Curlew Numenius arquata, and spring-staging Broad-billed Sandpiper Limicola falcinellus and Sanderling Calidris alba have also increased in the remaining areas. With the proposed continuation of land reclamation in Bohai Bay, we predict waterbird densities in the remaining areas to increase to a point of collapse. To evaluate the future of these fragile, shared international resources, it is vital to promote an immediate conservation action plan for the remaining coastal wetlands in this region, and continued population monitoring to determine the effects of this action.

Galliform birds (relatives of the chicken and turkey) have attracted substantial attention due to their importance to society and value as model systems. This makes understanding the evolutionary history of Galliformes, especially the species-rich family Phasianidae, particularly interesting and important for comparative studies in this group. Previous studies have differed in their conclusions regarding galliform phylogeny. Some of these studies have suggested that specific clades within this order underwent rapid radiations, potentially leading to the observed difficulty in resolving their phylogenetic relationships. Here we presented analyses of six nuclear intron sequences and two mitochondrial regions, an amount of sequence data larger than many previous studies, and expanded taxon sampling by collecting data from 88 galliform species and four anseriform outgroups. Our results corroborated recent studies describing relationships among the major families, and provided further evidence that the traditional division of the largest family, the Phasianidae into two major groups (“pheasants” and “partridges”) is not valid. Within the Phasianidae, relationships among many genera have varied among studies and there has been little consensus for the placement of many taxa. Using this large dataset, with substantial sampling within the Phasianidae, we obtained strong bootstrap support to confirm some previously hypothesized relationships and we were able to exclude others. In addition, we added the first nuclear sequence data for the partridge and quail genera Ammoperdix, Caloperdix, Excalfactoria, and Margaroperdix, placing these taxa in the galliform tree of life with confidence. Despite the novel insights obtained by combining increased sampling of taxa and loci, our results suggest that additional data collection will be necessary to solve the remaining uncertainties.

Abstract. We monitored numbers of Red Knots (Calidris canutus) staging in Bohai Bay, China (39 02 0 N, 118 15 0 E) on northward migration. Knots were identified to subspecies, and we systematically searched for colour-banded birds from the non-breeding grounds. We modelled migratory turnover, and revised estimates of flyway population using recently published counts from the non-breeding grounds. Two Russian-breeding subspecies occurred at our study site: C. c. rogersi