All parrots are part of the taxonomic order Psittaciformes. To qualify as a parrot, birds must have a hookbill and zygodactyl feet – 4 toes, 2 pointing forward and 2 backward.
This scientific classification of parrots divides into 4 families: Psittacidae, Cacatuoidea, Strigopidae, and Psittaculidae. All members of these parrot families share certain characteristics.
The order Cacatuoidea is exclusive to cockatoos and cockatiels – birds with a head crest. 4 living parrot species belong to the Strigopidae family, all of which are native to New Zealand and very rarely exported due to dwindling wild populations.
Psittaculidae parrots are native to the Old World – nations in Africa, Asia, and Europe recognized as populated in ancient times before explorers charted a course across the globe and discovered the Americas.
Psittacidae parrots dwell in the ‘New World,’ primarily Australasia, the Amazon rainforests of South America, and African nations not discovered by the West until late into the 19th Century.
Parrot order classification is managed by the Integrated Taxonomic Information System (ITIS,) a partnership between multiple federal government bodies formed in 1996.
As scientific understanding of the animal kingdom regularly changes, parrot genus classification may be revised as and when new data comes to light.
What Is A Taxonomic Rank?
Taxonomic rank is a science-based classification of all living things, devised by the Swedish botanist Carl Linnaeus, published and popularized in his 1735 work Systema Naturae.
Taxonomic rank is broken into 8 sub-sections:
Domain
Phylum is a further breakdown of the Kingdom. Archaea and Eubacteria comprise around 34 phyla, fungi have 7, plants have 12, and roughly 35 animal phyla.
Most animals with backbones, including all birds, belong to the phyla Chordata.
Kingdom
The U.S. and Canada recognize 6 Kingdoms of taxonomic rank – Animalia (animals,) Plantae (plants,) Fungi, Protista (algae, mold, or amoebae,) Archaea, or Eubacteria (both forms of bacteria.)
As Domain also covers bacteria, scientists of other nations combine Archaea and Eubacteria into a single Kingdom called Monera, making 5 Kingdoms.
Phylum
Phylum is a further breakdown of the Kingdom. Archaea and Eubacteria comprise around 34 phyla, fungi have 7, plants have 12, and roughly 35 animal phyla.
Most animals with backbones, including all birds, belong to the phyla Chordata.
Class
Class breaks down the Phylum further. For example, birds and reptiles are part of the Chordata phyla, but Class divides the animals into sub-categories based on shared characteristics.
Birds like parrots belong to the Aves Class, while other Classes include Reptilia, Amphibia, and Mammalia.
Order
Order separates animals of the same Class into 23 different categories. As discussed, parrots belong to the Psittaciformes order. This term is an adaptation of Psittacus, the ancient Greek word for parrot.
Family
The Order of Aves breaks into 142 separate Families. Psittaciformes are split into 4 core families – Psittacidae, Cacatuoidea, Strigopoidea, and Psittaculidae.
Genus
Parrot Families comprise 101 further Genera. The Genus of a parrot forms the first part of the bird’s Latin name and reveals the parrot’s core genetic makeup.
Examples of Genera in parrots include Amazona (Amazon parrots,) Poicephalus (many African parrots, including the Senegal parrot,) and Ara (macaws.)
Species
The species makes up the second part of the bird’s Latin name. Every parrot is identified as a unique Species, though some are considered sub-species and have a three-word Latin name to reflect this.
Educators use the mnemonic Dear King Philip Came Over For Good Soup to remember these 8 criteria.
All parrots have an identical Domain, Kingdom, Phylum, Class, and Order, but Family, Genus, and Species vary according to the individual bird.
The taxonomic rank of 3 common parrots is as follows:
| American Budgie | Cockatiel | African Grey | |
| Domain | Eukaryote. | Eukaryote. | Eukaryote. |
| Kingdom | Animalia. | Animalia. | Animalia. |
| Phylum | Chordata. | Chordata. | Chordata. |
| Class | Aves. | Aves. | Aves. |
| Order | Psittaciformes. | Psittaciformes. | Psittaciformes. |
| Family | Psittaculidae. | Cacatuoidea. | Psittacidae. |
| Genus | Melopsittacus. | Nymphicus. | Psittacus. |
| Species | Undulatus. | Hollandicus. | Erithacus. |
What Are The Families of the Psittaciformes Order?
Over 400 recognized parrot species belong to the Psittaciformes order, although around a dozen species are extinct. The surviving members are divided into 4 families based on physical characteristics:
Cacatuoidea (Cockatoos)
Cacatuoidea is a psittacine superfamily that splintered off to accommodate the Cacatuidae family.
21 different species of bird fall under the Cacatuidae family across 6 genera, with all cockatoos and cockatiels part of this family.
Cacatuidae birds are primarily found in Australia, Indonesia, the Philippines, Puerto Rico, Taiwan, the Solomon Islands, and Hong Kong.
Some of these territories have substantial colonies of Cacatuidae parrots in urban areas due to erstwhile owners releasing pets into the wild. Cacatuidae parrots have long lifespans and regularly breed, expanding their population.
The primary characteristic of a Cacatuidae parrot is the presence of a crest at the top of the head.
Subtler biological differences include the presence of a gall bladder and a lack of oil glands on the feathers to facilitate preening.
While many of these birds are popular and widely available as pets, others – notably the red-vented cockatoo (Cacatua haematuropygia) – are endangered.
Popular Cacatuidae parrots kept as pets with minimal legal or administrative complications include:
- Bare-Eyed Cockatoo (Cacatua sanguinea.)
- Black Palm Cockatoo (Probosciger aterrimus,) aka the Goliath Cockatoo.
- Citron-crested Cockatoo (Cacatua sulphurea citrinocristata.)
- Cockatiel (Nymphicus hollandicus.)
- Goffin’s Cockatoo (Tanimbar corella.)
- Major Mitchell’s Cockatoo (Lophochroa leadbeateri.)
- Rose-breasted Cockatoo (Eolophus roseicapilla,) aka Galah.
- Salmon-crested cockatoo (Cacatua moluccensis.)
- Slender-Billed Cockatoo (Cacatua tenuirostris.)
- Sulphur-crested Cockatoo (Cacatua galerita.)
As Cacatuidae parrots have similar DNA, a significant amount of cross-breeding occurs in the wild. This keeps scientists on their toes, as new sub-species are frequently identified.
The Cacatuoidea superfamily is distinct from most other parrots, including those in the same terrain. This is why cockatoos and cockatiels retain their unique physical appearance compared to other psittacines.
Psittacidae (African and New World Parrots)
Psittacidae is the first of two superfamilies of “true parrots,” the other being Psittaculidae.
The fundamental difference between these two superfamilies is their native territory and preference for tropical climates.
Parrots that belong to the Psittacidae family are also known as holotropic parrots.
This family contains 181 species of parrots across 34 genera, most of whom hail from the former supercontinent of Gondwana. This includes South and Central America, Australasia, South Asia, the Caribbean, and sub-Saharan Africa.
Systematic Biology theorizes that Psittacidae parrots are ancestors of the Cacatuoidea superfamily, diverging some 33 million years ago. Today, examples of Psittacidae species that are kept as pets include:
- African grey parrots (Psittacus erithacus.)
- Multiple sub-species of Amazon parrots (Amazona.)
- Blue-headed pionus (Pionus menstruus.)
- Caique parrots (Pionites xanthurus, Pionites xanthomerius, or Pionites melanocephalus, depending on the sub-species.)
- Multiple sub-species of macaw, most notably the military macaw (Ara militaris,) scarlet macaw (Ara macao,) Hahn’s macaws (Diopsittaca nobilis nobilis,) and Hyacinth macaws (Anodorhynchus hyacinthinus.)
- Pacific parrotlets (Forpus coelestis.)
- Quaker parakeets (Myiopsitta monachus,) aka monk parakeets.
- Senegal parrots (Poicephalus senegalus.)
- Sun conures (Aratinga solstitialis) or green-cheeked conure (Pyrrhura molinae.)
An additional 4 species of Psittacidae parrots have been declared extinct.
- Carolina parakeet (Conuropsis carolinensis) was declared extinct in 1918.
- Cuban macaw (Ara tricolor) has been extinct since the 19th Century.
- Glaucous macaw (Anodorhynchus glaucus) was last seen in the 18th Century and is believed extinct.
- Puerto Rican parakeet (Psittacara maugei) was hunted to extinction in the 19th Century.
The Psittacidae family represents some of the world’s most celebrated and renowned parrot species.
Psittaculidae (Old World Parrots)
The Psittaculidae superfamily of parrots is the most prominent psittacine family, hosting 204 species (13 of which are now extinct) over 54 genera. While there is no difference in age between these birds and Psittacidae parrots, many species of Psittaculidae were discovered first.
Few species from the Psittaculidae family are imported into the U.S., although those kept as pets are extremely common.
Other than wild Psittaculidae and Psittacidae parrots hailing from different locations, Psittacidae birds are often smaller than their New World counterparts. Most Psittaculidae parrots are found in Asia, New Guinea, or Australia. Popular pets from this family include:
- Budgerigar (Melopsittacus undulatus.)
- Eclectus parrot (Eclectus roratus.)
- Masked lovebird (Agapornis personata.)
- Rose-ringed parakeet (Psittacula krameri,) aka Indian ringneck.
Lorikeets are also now considered Psittaculidae parrots, despite formerly holding status as a sub-family of the Psittacinae dubbed Loriinae. This adjustment was made after it was discovered that lorikeets are closely related to budgerigars.
Strigopidae (New Zealand Parrots)
The Strigopidae is the smallest surviving family of parrots, with just 4 living species.
Each of these parrots is native to New Zealand, where they still live. The names of Strigopidae parrots are derived from traditional Māori words.
These parrots are considered a separate family from other psittacines as scientists believe they diverged from the DNA of other parrots some 80 million years ago, during the Cretaceous period.
Parrots found in neighboring countries aren’t a genetic match to Strigopidae birds. However, a handful of Psittaculidae and Cacatuidae species from Australia have been introduced to New Zealand and maintain a small population. The surviving species of Strigopidae parrots are as follows.
- Kea (Nestor notabilis.)
- South Island kākā (Nestor meridionalis meridionalis.)
- North Island kākā (Nestor meridionalis septentrionalis.)
- Kākāpō (Strigops habroptila.)
New Zealand was home to the Norfolk kākā (Nestor products,) which was declared extinct in the 19th Century, and the Chatham kākā (Nestor chathamensis,) which died out in the 17th Century.
Fossils suggest that New Zealand also formerly hosted Heracles inexpectatus, a cannibalistic parrot that stood 90 cm tall and died out up to 19 million years ago.
The kea and both surviving kākā species are endangered, while the kākāpō is critically endangered. According to Cell Genomics, only around 200 kākāpō were alive in 2021, but this has risen slightly in 2023.
The kākāpō is the world’s only flightless parrot. It’s also the heaviest parrot at around 6 lbs. Most kākāpō parrots have been transported to 4 small predator-free islands to conserve the species.
Deforestation of the kea’s natural habitat, an aging population, and high mortality in chicks led to this parrot’s endangered status. Most living Kea parrots dwell on and around clifftops in New Zealand.
Kākā parrots almost became extinct due to losing their forest habitat, but conservation programs have succeeded. A substantial North Island kākā parrot population has colonized the capital city of Wellington due to the ecosanctuary Zealandia.
