Green R.E., Hirons G.M. & Kirby J.S. (1990) The effectiveness of nest defense by Black-Tailed Godwits Limosa limosa. ARDEA 78 (3): 405-413

This paper describes measurements of the frequency of aerial attacks on avian predators by nesting Black-tailed Godwits. The effects of these attacks on the ranging behaviour of Carrion Crows and the removal of eggs from artificial nests are assessed and compared with the effects of similar attack behaviour by Lapwings. A high proportion of the Carrion Crows and Grey Herons that approached Godwit colonies were attacked. Kestrels were attacked when Godwits had chicks but tended to be tolerated when they were incubating. This difference may be related to the risk of predation from this species at the two stages of breeding. Attacks by Godwits were more effect than those by Lapwings in excluding Carrion Crows and protecting artificial nests even though Lapwings attacked Crows in larger groups. It is speculated that body size has an important influence on the effectiveness of attacks on predators and the advantages of communal nest defence.