Introduction Transhumant and nomadic animal husbandry is a widely practised strategy in the whole of South Asia. As a response to a seasonal resource scarcity in one region, most transhumant and nomadic communities move in search of feed and water for their herds or flocks of sheep, goats, cattle and camels. This paper is a study of such nomadic herders in southern India who move with an as yet little documented type of herd--ducks. These families migrate across vast tracts, relying largely on modern technologies, credit arrangements and markets. Cultivation by farmers of short duration high yielding varieties of paddy, roads and transport networks, credit arrangements, incubator hatched eggs, markets for sale of their eggs and meat are some of the modern technologies around which their nomadism is built. Thus, although natural resource based, several technological and financial inputs are crucial for this form of animal husbandry, and indeed this form of herd management is a recent development that has only come into existence in the last twenty-five years. Data used in this paper were collected at various times between March 1987 (Vania 1994) and February 2000 from fourteen districts in the southern Indian province of Tamil Nadu, in addition to information obtained from eight nomadic duck herders and from two egg sellers/financiers at Polur and Ami towns of Thiruvannamalai District. Duck Herding and Multidimensional Agro-Ecosystems According to the Indian Livestock Census of 1987, the duck population was 23.48 million, or 8.53 per cent of the total poultry population in the country. Ninety-two per cent of this comprised of local breeds. The provinces of West Bengal, Assam, Bihar, Manipur, Kerala, Andhra Pradesh, Tamil Nadu and Orissa have a sizeable duck population (Ramakrishnan 1996). India has twenty-four breeds and thirty-four varieties of local ducks (Bhat et al. 1980). While there are several small sedentary groups of breeders, nomadic duck herders keep moving their herds in a cyclic fashion from one region to another, depending on the amount of feed available, on rainfall and cropping patterns. Ducks are mostly reared for eggs, but also consumed as meat. In Tamil Nadu, villages shun their consumption due to the belief that these eggs and meat have a peculiar smell and produce excessive gas in the stomach and also lead to joint pains. Such beliefs do not seem to be shared by people in Kerala and West Bengal, whose food consumption patterns, with their stress on fish and meat also include duck eggs. Duck herd sizes range anywhere between 100 and 600 birds. An economically viable threshold herd size is 100, the maximum being 600. A single person is required to manage up to 200 ducks, a herd of 600 thus being managed by a maximum of three. The economic threshold of 100 is based on a male to female ratio of 1:12 and the viability of a herd on the production of at least seventy eggs per day. The male to female ratio in Kerala, Andhra Pradesh and Tamil Nadu differ, depending on the breed of duck. The migration patterns of the domesticated duck is tied temporally and spatially to regions where paddy is the chief crop, and one of the many features of the domesticated duck in India is its link to the south Indian paddy agro-ecosystem. Agro-ecosystems are overwhelmingly complex systems. Apart from food subsistence and/or commercial production, they are inter-wined in India with the livestock sector and provide a range of opportunities for land based livelihoods. Paddy cultivation involves transplanting paddy from seedling beds or direct sowing. Selection by nature and humans over long periods of time has shaped rice and many other crops in such a fashion as to synchronise their ripening, to maximise the harvest of fully mature grains. In spite of this, variations among seeds throw up early or late maturing individuals. Such early maturing, over-ripe paddy drops to the ground from the panicle. …