This image by Dato’ Dr Amar-Singh HSS shows a wintering adult Grey Wagtail (Motacilla cinerea) with a caterpillar prey. It was taken at the secondary forest in the interior of Tambun, Perak, Malaysia on 5th September 2009.
“This Grey Wagtail is another one of our early winter migrants from the north. It has a protracted “autumn” passage (some records of arrivals in late July). I have often seen them in mid-August.
“This adult was beside a moderate sized river, walking in the mud on the logging trail. It caught a green caterpillar, bashed it on the ground a few times before swallowing it whole.
“Little is known about its prey apart from ‘small invertebrates from the margins of water’ (Wells, 2007).”
Tyler (2004) however gives a long list of its prey, mainly insects, notably fly larvae and adults, etc.
1. Tyler, S. J., 2004. Family Motacillidae (Pipits and Wagtails). In: del Hoyo, J., Elliott, A. & Sargatal, J. eds. Handbook of the birds of the world. Vol. 9. Cotingas to Pipits and Wagtails. Lynx Editions, Barcelona. Pp. 686-786.
2. Wells, D.R., 2007. The birds of the Thai-Malay Peninsular. Vol. II, Passerines. Christopher Helm, London. 800 pp.
All images by Amar-Singh HSS (Dato, Dr)