Ecology and Evolution of Cooperative Breeding in Birds: Fitness consequences of helping

摘要: Cooperatively or communally breeding birds are species in which individuals live groups of three more breeding-aged adults, all care for young at a single nest (Brown 1987; Stacey and Koenig 1990a). Most cooperative breeders retain that delay help their parents raise siblings. Additional forms include polygamous with multiple cobreeders one both sexes and, rarely, unrelated helpers. Cooperative is rare, occurring only about 3% avian worldwide, particularly common Australian Russell 1989; Arnold Owens 1998). Its prevalence Australasia can be accounted phylogenetically due to high frequency the Corvida (23%) (Russell Edwards Naeem 1993; Clarke 1995). Theoretical comparative treatments have usually dealt full range social systems et al. 1992; Hartley Davies 1994; This practice has demonstrated share many important characteristics, such as year-round residency, survivorship, small clutch sizes, cases, constraints on independent 1990a; 1998, 1999). Specific limitations vary from next, involve variety resources, including food, territories, suitable roosting sites, lack skill mates (Smith 1990). The primary focus this chapter helping by retained offspring.