The true koels, Eudynamys, are a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of cuckoo

Cuckoo

The cuckoos are a family, Cuculidae, of near passerine birds. The order Cuculiformes, in addition to the cuckoos, also includes the turacos . Some zoologists and taxonomists have also included the unique Hoatzin in the Cuculiformes, but its taxonomy remains in dispute...

s from Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

, Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 and the Pacific. They are large sexually dimorphic

Sexual dimorphism

Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...

 cuckoos which eat fruits and insects and have loud distinctive calls. They are brood parasite

Brood parasite

Brood parasites are organisms that use the strategy of brood parasitism, a kind of kleptoparasitism found among birds, fish or insects, involving the manipulation and use of host individuals either of the same or different species to raise the young of the brood-parasite...

s, laying their eggs in the nests of other species.

In New Zealand the Long-tailed Koel is known as the Long-tailed Cuckoo. Two other species, the White-crowned Koel

White-crowned Koel

The White-crowned Cuckoo or White-crowned Koel is a species of cuckoo in the Cuculidae family. It is often placed in the monotypic genus Caliechthrus but it has a similar song to cuckoos of the genus Cacomantis and is genetically similar to the Pallid Cuckoo...

 and the Dwarf Koel

Dwarf Koel

The Dwarf Koel is a species of cuckoo in the Cuculidae family. It is monotypic within the genus Microdynamis.It is found in Indonesia and Papua New Guinea.Its natural habitat is subtropical or tropical moist lowland forests....

, are also known as koels but are in their own monotypic

Monotypic

In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...

 genera.

Taxonomy

The taxonomy

Taxonomy

Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...

 of the common koel

Common koel

The common koels are three species of cuckoos. They have commonly been considered conspecific under the scientific name Eudynamys scolopaceus, but are increasingly treated as separate species:* Asian Koel, Eudynamys scolopaceus....

 complex

Species complex

A species complex is a group of closely related species, where the exact demarcation between species is often unclear or cryptic owing to their recent and usually still incomplete reproductive isolation. Ring species, superspecies and cryptic species complex are example of species complex...

 is difficult and remains a matter of dispute, with some only recognizing a single species (Common Koel, Eudynamys scolopaceus, with melanorhynchus and orientalis as subspecies), two species (Common Koel, Eudynamys scolopaceus, with orientalis as a subspecies, and Black-billed Koel, Eudynamys melanorhynchus) or three species (as done below).

• Genus Eudynamys - true koels
  • Asian Koel
    Asian Koel
    The Asian Koel is a member of the cuckoo order of birds, the Cuculiformes. It is found in South Asia, China, and Southeast Asia. It forms a superspecies with the closely related Black-billed and Pacific Koels which are sometimes treated as subspecies...
    
    , Eudynamys scolopaceus
  • Black-billed Koel
    Black-billed Koel
    The Black-billed Koel is a species of cuckoo in the Cuculidae family. It is endemic to forest and woodland on the Indonesian islands of Sulawesi, Sula, Banggai, Togian and other smaller nearby islands. It has often been considered conspecific with E. scolopaceus, but they are increasingly treated...
    
    , Eudynamys melanorhynchus
  • Pacific Koel
    Pacific Koel
    The Pacific Koel , also known as the Eastern Koel, is a species of cuckoo in the Cuculidae family. It has often been considered conspecific with the Asian and Black-billed Koels, but they are increasingly treated as a separate species...
    
    , Eudynamys orientalis
    • Australian Koel, Eudynamys (orientalis) cyanocephalus
  • Long-tailed Koel, Eudynamys taitensis
  • Henderson Island Koel, Eudynamis cf. taitensis - prehistoric
    Late Quaternary prehistoric birds
    Prehistoric birds are various taxa of birds that became extinct before recorded history, or more precisely, before they could be studied alive by bird scientists...