Eastern Curlews Numenius madagascariensis feeding on Macrophthalmus and other ocypodid crabs in the Nakdong estuary, South Korea

Foraging Eastern Curlews were studied in the Nakdong Estuary, South Korea, in September 1984. During low tide Eastern Curlews spent on average 75–90% of their time foraging. They only ate crabs that had carapace widths 0.6 to 4 cm. Most crabs were captured with bill-deep probes in the crab-burrows....

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Bibliographic Details
Published in:Emu - Austral Ornithology
Main Author: Piersma, T.
Format: Article in Journal/Newspaper
Language:English
Published: 1986
Subjects:
Online Access:https://hdl.handle.net/11370/62c38a37-f7c7-4886-b2ce-e3dad18aeb50
https://research.rug.nl/en/publications/62c38a37-f7c7-4886-b2ce-e3dad18aeb50
https://doi.org/10.1071/MU9860155
Description
Summary:Foraging Eastern Curlews were studied in the Nakdong Estuary, South Korea, in September 1984. During low tide Eastern Curlews spent on average 75–90% of their time foraging. They only ate crabs that had carapace widths 0.6 to 4 cm. Most crabs were captured with bill-deep probes in the crab-burrows. The majority of prey were the ocypodid crab species Macrophthalmus japonicus. Crabs with carapace widths longer than 2 cm were softly shaken to dismember their legs before consumption. The Eastern Curlew's average intake rate was estimated at 1.95 mg ash-free dry weight (AFDW) per sec foraging. Profitability (mg AFDW/sec-handling) increased more than threefold over the range 0.6–3 cm carapace width. Comparisons with the foraging behaviour of two other curlew species, the Whimbrel Numenius phaeopus and the Eurasian Curlew N. arquata, feeding on ocypodid fiddler crabs, are made. It is suggested that the easily available and abundant small crabs are not consumed because their profitability is too low.