By Gina Cioli/Bowtie Studio/Courtesy Jennifer Ketchersid
The Congo African grey (Psittacus erithacus erithacus) is one of two subspecies of the species Psittacus erithacus. The word "species" comes from the same root as the word "specific," and it means the same thing.
Taxonomy may sound complicated, but it’s a straightforward way to order and classify organisms. The way organisms are named and arranged explains their biological relationship to each other. It is also commonly known as binomial nomenclature, and it simply means a naming system that assigns each species two names: the genus and species.
The individual who designed this formal system of labeling was Swedish botanist Carolus Linnaeus. In the early 1700s, Linnaeus attempted to come up with formal names for everything in nature and gave every organism a two-part name. He originally included minerals in his system of classification, but it has since been dropped.
Biology instructor Jason Crean explained, “Linnaean mineral classification was very artificial because it was difficult at that time to analyze minerals with anything more than the naked eye. That system would have perhaps worked if Linnaeus had knowledge of the chemical elements that composed the minerals he studied. His classification system was built simply on visual physical characteristics, which works better for living organisms.”
Two-Word Naming System
There is an advantage to this naming and classification because it is easy to identify any species with just two words. These two words can be used all over the world in any language. When a species is referred to by its Latin or scientific name, a person will know precisely what organism it refers to, and this aids in avoiding confusion. For instance, there are many common names for the species Psittacus erithacus erithacus: Congo African grey, grey parrot or red-tailed parrot. Using the scientific name removes all doubt as to what species and subspecies is being discussed.
Originally, the two-word naming system was referred to as the organism’s Latin name, but it has become preferable to refer to it as the scientific name. This is due to the fact that, in the ongoing process of naming organisms and reclassifying others, not all names have a Latin origin to them. The people who work in this field of naming organisms and maintaining the clarity of these names are called taxonomists.
Since Linnaeus set up the original two-part naming system, a seven-category system was created, and it is set up in a way that each category includes the smaller, more specific categories below it. They are: kingdom, phylum, class, order, family, genus and species. The species can be broken down even further to include subspecies of the species if there are members of the species with even smaller differences but there there will always be two or more subspecies or none at all. The differences in subspecies is usually attributed to their evolvement as a result of geographical distribution.
The groups at the top are broad with many members, and the categories get narrower as you work down the list. Each classification gets smaller, further defining each set of organisms until you have only the two-part scientific name for any particular organism. The position of each organism in a category denotes its relationship to other organisms. For instance, the largest group is the kingdom. The kingdom level identifies whether an organism is an animal or one of the other five classifications that are kingdoms including plants, fungi, bacteria (single-celled organisms that don’t have a nucleus) and protists (single-celled organisms that have a nucleus).
The next and narrower group or rank is the phylum. There are 36 animal phyla, but only nine include more than 96 percent of animal species.
Birds are in the kingdom Animalia and belong to the phylum Chordata, which designates them as being vertebrates. The class Aves identifies them as being birds and having feathers. From there on, birds are classified according to various characteristics. The chicken, while it belongs to the class Aves, is in the next classification down, in the order called Galliformes where it shares this classification with similar species, such as the turkey, grouse and quail. This is where these species part company. While they share some similar characteristics, they are divided further into another defining group called the family. The chickens are in the family Phasianidae, which include pheasants, partridge and junglefowl due to some similarities they have with these other species. But, again, the narrowing of the species types continues and they are classified into a smaller group called the genus. The term genus is derived from the same Latin word that means kind, sort, class and category. Chickens belong to the genus Gallus, because it is thought that they are descendants of the red junglefowl who also belong in Gallus.
Finally, the chicken has come home to its own species, Gallus gallus, although it still shares that species with junglefowl. The next step was to give the chicken its own home in the subspecies, Gallus gallus domesticus, which indicates the domestication of this bird.
What's A Subspecies?
What exactly is a subspecies? A subspecies is two or more members of the biological classification species. They generally share many of the same characteristics but do have their slight differences. Two members of the same species could possibly interbreed, and produce fertile offspring, but usually don’t very often due to differences in breeding season, geographic separation or a myriad of other factors.
The term, nominate subspecies simply means that the subspecies shares the same name as the species and can be identified by the repetition of the species name, such as the Congo African grey’s name, Psittacus erithacus erithacus.
Sometimes there is question as to whether a member is a full species or a subspecies. In these cases where there is doubt or disagreement, the species name is usually written in parentheses.
There are some simple rules when using these terms. When referring to a specific species, the genus name is used first and is capitalized, followed by the species name (which is not capitalized) and is called the specific descriptor or specific name. In print, species names are usually in italics and if it is handwritten, each word is underlined individually.
There are certain customs in naming each organism, but it is generally accepted that the person who discovers it has the privilege of naming it. The name can come from anywhere. Latin or Greek terms are commonly used in the two-part name, but sometimes inside jokes and puns are used. There are numerous references in these species names to favorite books, people, sport figures, actors and film makers.
The Far Side cartoonist and creator Gary Larson has three species named after him, including the beetle Garylarsonus and the Serratoterga larsoni butterfly. There is a species of ant named after the actor Harrison Ford as a way of honoring his work in conservation. It’s called Pheidole harrisonfordi. Mastophora dizzydeani (Eberhard) is a spider named after the famous baseball player, Dizzy Dean. This species is the name of a spider that uses a sticky ball on the end of a thread to catch its prey. If you were to translate the name of the dinosaur Dracorex hogwarsia into English, you would get “Dragon King of Hogwarts.”
A clam taxonomist waited many years for the opportunity to name a clam from the genus, Abra. His choice? Abra cadabra, of course! Apparently even taxonomists have a sense of humor!
Scientific Classification Using the Congo African Grey As An Example
This denotes that the Congo African grey is an animal as opposed to a plant or belonging to another kingdom.
This explains that the Congo African grey belongs to the group that includes vertebrates.
This states that the Congo African grey is a bird.
This notes what type of bird the Congo African grey. The Congo African grey is a parrot.
This defines the Congo African grey as a “true parrot.” There is some controversy about the term true parrot, as there is disagreement over the inclusion of cockatoos in this family. There are some distinct anatomical differences between “true parrots” and members of the Cacatuidae or cockatoo family. Some of these differences, including the cockatoo’s movable head crest, a distinctly different layout of the carotid arteries and possessing a gall bladder are just a few of the unmistakable dissimilarities between cockatoos and other parrots.
This means that this bird is a grey parrot.
Species: P. erithacus
This narrows this bird down to a large grey parrot with a red-colored tail and commonly found in Africa. The word erithacus comes from the Greek word erythro, which means red.
Subspecies: P. erithacus erithacus
The Congo African grey now has its own place as the large grey bird with a bright red tail and a black beak.
There is another common subspecies, the Psittacus erithacus timneh, or the Timneh African grey. This subspecies is distinct from the Congo African grey with its smaller size, maroon-colored tail, and horn-colored beak. As with many species, there are some aviculturalists who recognize a third, and sometimes even a fourth subspecies, but they have not yet been proven to be distinct in scientific studies.