Over ten thousand species numbering millions of animals migrate every year, and they face some of the highest rates of extinction. Because they are integral to multiple ecosystems, migratory species serve as effective indicators of environmental changes. Migratory species make many contributions to ecosystem structure and function. On land, by moving between areas they inhabit at different times of the year in search of food, shelter and safe places to breed, they act as fertilizers, pollinators and seed distributors. They provide food for other animals, and some are useful predators (e.g. by consuming agricultural pests like insects). Migratory species sustain multi-billion dollar economic activities such as large-scale commercial fishing and world-wide tourism such as whale and bird watching. Prolonged drought leading to desertification is a key threat to dryland species and hampers the ecosystem services they provide.

Animals fertilize the soil with their droppings and help plants germinate, and their movement loosens the soil to increase vegetation productivity. They consume biomass and so reduce fireloads. Many rural communities in the drylands rely on the annual influx of migratory wildlife for basic subsistence, and recreational and spiritual purposes, while conservation efforts contribute to poverty alleviation. Helping people move into alternative livelihoods such as ranger, farming or tourism activities ensures the active involvement of communities on the one hand and the sustainable use of natural resources on the other. However as desertification advances, migratory species are vanishing.