Does coevolution promote species richness in parasitic cuckoos?

Abstract

Why some lineages have diversified into larger numbers of species than others is a fundamental but still relatively poorly understood aspect of the evolutionary process. Coevolution has been recognized as a potentially important engine of speciation, but has rarely been tested in a comparative framework. We use a comparative approach based on a complete phylogeny of all living cuckoos to test whether parasite–host coevolution is associated with patterns of cuckoo species richness. There are no clear differences between parental and parasitic cuckoos in the number of species per genus. However, a cladogenesis test shows that brood parasitism is associated with both significantly higher speciation and extinction rates. Furthermore, subspecies diversification rate estimates were over twice as high in parasitic cuckoos as in parental cuckoos. Among parasitic cuckoos, there is marked variation in the severity of the detrimental effects on host fitness; chicks of some cuckoo species are raised alongside the young of the host and others are more virulent, with the cuckoo chick ejecting or killing the eggs/young of the host. We show that cuckoos with a more virulent parasitic strategy have more recognized subspecies. In addition, cuckoo species with more recognized subspecies have more hosts. These results hold after controlling for confounding geographical effects such as range size and isolation in archipelagos. Although the power of our analyses is limited by the fact that brood parasitism evolved independently only three times in cuckoos, our results suggest that coevolutionary arms races with hosts have contributed to higher speciation and extinction rates in parasitic cuckoos.

Visual mimicry of host nestlings by cuckoos

“…This could explain why Horsfield's bronzecuckoos are monotypic, whereas shining bronze-cuckoos comprise four subspecies and there are 10 or more subspecies of little bronze-cuckoo [42]. Furthermore, if cuckoo chick rejection by hosts proves to be more common than is currently thought, it might also explain the recent evidence that species richness is higher in parasitic cuckoos than non-parasitic cuckoos [55].…”

Coevolution is linked with phenotypic diversification but not speciation in avian brood parasites

“…In theory, coevolution of brood parasites and hosts should lead to increased rates of diversification and increased phenotypic diversity [2,19]. We used two recently developed methods and phylogenies to test these hypotheses explicitly.…”

“…For example, brood parasitic Vidua finches, Vidua spp., underwent sympatric speciation as they annexed novel host species [15]. Moreover, specialization on particular host species has led to genetic divergence within some cuckoo and honeyguide species into distinct host-specific races [16][17][18], and Krü ger et al [19] demonstrated that species of parasitic cuckoos had more subspecies than species of non-parasitic cuckoos. Since the appearance of these studies, novel phylogenies [20] and phylogenetic methods [3,21] have been developed.…”

Bird responses to habitat change in the karst area of Bantimurung Bulusaraung National Park

“…Burung yang berasal dari familia Cuculidae dikenal sebagai burung yang bersifat parasit (Kruger et al, 2009;Ducatez, 2014). Penurunan jumlah individu dan jumlah spesies burung dari familia Cuculidae di areal karst yang mengalami gangguan, dapat mengindikasikan adanya penurunan spesies burung yang menjadi inang burung ini di areal yang mengalami gangguan.…”