Habitat management of little terns in Japan’s highly developed landscape
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Published source details
Fujita G., Totsu K., Shibata E., Matsuoka Y., Morita H., Kitamura W., Kuramoto N., Masuda N. & Higuchi H. (2009) Habitat management of little terns in Japan’s highly developed landscape. Biological Conservation, 142, 1891-1898.
Published source details Fujita G., Totsu K., Shibata E., Matsuoka Y., Morita H., Kitamura W., Kuramoto N., Masuda N. & Higuchi H. (2009) Habitat management of little terns in Japan’s highly developed landscape. Biological Conservation, 142, 1891-1898.
Summary
Provide artificial nesting sites for ground and tree-nesting seabirds
A before-and-after study in 2001–2007 on a rooftop in Tokyo, Japan (Fujita et al. 2009) reported that adding artificial substrates typically increased little tern Sterna albifrons nest density and hatching success. These results are not based on assessments of statistical significance. In 2001, little terns nested on a bare concrete roof (80 nests) but only 2% of eggs hatched. In 2002–2007, part or all of the roof was covered in artificial substrates. In five of six years, terns performed better than in 2001. This was true for both number of nests (140–1,990) and hatching success (15–62%). In the other year there was only one nest, which failed. The study also compared different types of artificial substrate. Breeding performance was better on crushed concrete than brown “sludgerite” grains, for both nest density (concrete: 0.040; sludgerite: 0.005 nests/m2) and egg predation rate (concrete: 43%; sludgerite: 48%). Artificial substrates were added to the 6-ha rooftop in stages, covering 30-100% of the roof each year. Substrates were crushed concrete, 3-cm-diameter grey ballasts, or 2–3-mm-diameter “sludgerites” (brown granules made from reclaimed sewage ash).
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