Most mimid species build open-cup nests, usually situated at heights of 3-6 ft (1-2 m) in bushes. The exceptions are the pearly-eyed thrasher (Margarops fuscatus) of the West Indies, which builds a bulky stick nest in cavities of trees and the two tremblers, found in the Lesser Antilles, whose nests are domed structures with side entrances. Desert species, such as Leconte's thrasher (Toxostoma lecontei), take great care to position their nests in such a way as to take greatest advantage of shade. Egg color is variable within the family; most thrashers (Toxostoma) and mockingbirds (Mimus) lay speckled or spotted eggs, with either a whitish or greenish background, but catbirds (Dumetella and Melanoptila), the Central American blue mockingbird (Melanotis caerulescens), and most of the endemic West Indian genera lay unmarked bluish or greenish eggs. Incubation is generally by both sexes in the thrashers, but by the female alone in mockingbirds and catbirds. In most species breeding is conventional (i.e. one male and one female per nest), but in the mockingbirds of the Galápagos Islands a complex system of social breeding has evolved, with a "territorial group" of birds, which in the case of the Hood mockingbird (Nesomimus macdonaldi) may number up to 40, defending a group territory. Within the group is a set hierarchy, the dominant male being the oldest bird. Up to four breeding females occur in a group,
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