Reproductive biology

In general, babblers form pairs in the breeding season, establish territories, raise one or two broods, then reassemble as flocks. Again, this seems to be the case for forest species, with most exceptions being birds of other habitat. The bearded reedling has evolved to produce up to four broods in quick succession each breeding season, with the first potentially able to breed themselves by season's end. The Arabian babbler's reproductive system, however, is remarkably different. Its highly regimented social units, with birds waiting as long as six years for their first opportunity to breed, is only the most extreme situation in its large and widespread genus Turdoides. Researchers have confirmed that at least 14, and possibly 26, of the 29 species in this genus practice some sort of cooperative breeding, with groups defending territories where only a few members will breed at any given time. The Turdoides are primarily open-country birds. In India, the tendency to always remain in their social unit has earned some species the name "Seven Sisters," and India's revered ornithologist Salim Ali refers to their groups as "sisterhoods." Another departure from the norm are the colonial picathartes, who use their unique, mud pottery-like nests, built on rock faces, as residences, and raise chicks in them year after year. Such nests are unique among babblers, who, in general, construct cup or bowl-shaped, or spherical, nests of plant materials, usually not far from the ground. Eggs run a spectrum from white and patternless, to various beautiful colors and intricate patterns of spots and streaks.

0 0

Post a comment