The extent of territoriality while breeding in poorly known for most species. Nests, however usually are well spaced (Johnsgard 1983) but occasionally are sited close together (e.g., Masterson 1986). Mated pair of non-migratory Sandhill Cranes defends territories (Nesbitt and Williams 1990). Some mated pairs remain on their territories throughout the year, while others vacate their territories during the post-breeding period. During the period after breeding, these cranes regularly feed in dryland habitats. Pairs having dryland habitats within their territories remain resident, while those without such habitat in their territories vacate them to flock with other cranes in dryland areas. Territoriality by family groups on the non-breeding grounds has been found in the Whooping (Allen 1952; Blankinship 1976), Hooded and Siberian Cranes. In the Hooded Crane, the protection of a food supply for the juveniles has been suggested as the reason for territoriality in the wintering quarters.