Mar. 11, 2013 — Extensive shell fishing and sewerage discharge in river estuaries could have serious consequences for the rare Icelandic black-tailed godwits that feed there. But it is the males that are more likely to suffer, according to new research from the
. University of East Anglia
Research published today in the journal Ecology and Evolution reveals very different winter feeding habits between the sexes.
|Black-tailed Godwit. (Credit: Tómas Gunnarsson)|
Both males and females mainly consume bivalve molluscs, sea snails and marine worms, probing vigorously into soft estuary mud with their long beaks. But the study shows that females, which are larger and have longer bills, are able to peck further into the silt to secure larger, deeper buried prey in areas that the shorter-billed males cannot reach. This means that human impacts on estuaries may have different impacts on males and females, depending on which prey sizes are most affected.
The godwit is a large, long-legged, long-billed migratory shorebird. It breeds almost exclusively in
and winters on western European coasts, from the UK
and Ireland in the north to
the Iberian Peninsula in the south.