Natural History of the Little Bustard: Morphology, Biometry, Diet, Sexual Dimorphism, and Social and Breeding Behaviour

The little bustard Tetrax tetrax is one of the smallest members of the family Otididae, and has many remarkable life history traits, in its anatomy, biology and ecology. Some of them are shared with other bustard species, but others are unique to the little bustard. In this chapter we first describe plumage and biometry. Moreover, we present and examine for the first time geographic and sexual variation in size, based on measurements on individuals from across the species’ range. These results indicate biometrical differences between eastern and western populations. Wing and tail lengths are greater in T. t. orientalis but tarsus length does not differ between former subspecies, and actually bill is larger in T. t. tetrax than in T. t. orientalis. Social and spacing behaviour, mating, and several aspects of breeding biology, i.e. life history traits (fecundity, life span) are reviewed. The little bustard is a sexually dimorphic exploded lekking species, whose males defend territories that females visit for mating. The male’s display repertoire includes both acoustic (snort call, ground foot stamping, and wing-flash whistling) and visual displays (neck display, wing flashing, jumps). Diet, both in summer and winter, and foraging ecology are also described. Little bustard diet is dominated by leaves and shoots of herbaceous plants (wild and cultivated), although arthropods are a key resource during breeding when they play a role in male territorial behaviour and are the major food source for growing chicks. Finally, we present results on male daily activity patterns during the mating season which show that vigilance dominates their time schedule.