A Taxonomic Review of Obligate and Facultative Interspecific Avian Brood Parasitism

Abstract

This chapter discusses the taxonomic relationships of brood parasites and their distribution through tribes, families and higher taxa, providing information about their breeding biology and host species when available. Distinction is made between obligate and facultative brood parasitism and, in the latter case, between interspecific and conspecific brood parasitism. It is shown that obligate brood parasites, with one exception, are all species that have altricial young, whereas facultative brood parasites, with two exceptions, all have precocial young. Reasons for this are discussed. Where data are available on success or failure of such parasitism, this is commented on. All known and suspected hosts are listed in the appendices. The possible evolutionary pathways between the three forms of brood parasitism (conspecific, facultative interspecific and obligate interspecific) are briefly discussed. Since obligate brood parasitism is shown to be a very effective way of increasing the individual’s fecundity, the reasons for only about 1% of bird species evolving this strategy are discussed.