The Snowy Egret, with its bright white plumage and distinctive yellow feet, is a small heron that can be found along shorelines and wetlands across North and South America. But what phylum does this elegant waterbird belong to? Let’s take a closer look at the classification of the Snowy Egret to find out.
Overview of Animal Classification
All living organisms are classified into groups based on shared characteristics. These groups create a hierarchy going from the broad to the specific. The highest level of classification is the kingdom. There are currently 6 recognized kingdoms – Animalia, Plantae, Fungi, Protista, Archaea/Archaebacteria, and Bacteria/Eubacteria. Under kingdom is the phylum level. A phylum is a large grouping of related organisms. There can be multiple phyla within a kingdom. Under phylum is class, then order, family, genus, and finally species at the most specific level.
So to determine the phylum of the Snowy Egret, we first need to know the kingdom and work down from there through the classification hierarchy. As a bird, the Snowy Egret belongs to the kingdom Animalia, which contains all animals.
Animalia Kingdom
The kingdom Animalia includes all multicellular eukaryotic organisms that obtain nutrition by ingesting other organisms. There are estimated to be anywhere from 2 million to 50 million animal species alive today. This incredible diversity means there are over 30 different animal phyla within the Animalia kingdom, each containing organisms with common ancestry and evolutionary history.
Some of the largest and most well-known animal phyla include:
- Arthropoda – insects, spiders, crabs, lobsters
- Mollusca – clams, snails, squid, octopus
- Chordata – fish, birds, reptiles, amphibians, mammals
- Cnidaria – jellyfish, coral, sea anemones
- Echinodermata – starfish, sea urchins, sand dollars
As we determine where the Snowy Egret fits into this classification hierarchy, the first step is identifying which of these large phyla it belongs to within the Animalia kingdom. Based on the fact that the Snowy Egret is a bird, we can immediately narrow it down to the phylum Chordata.
Chordata Phylum
The phylum Chordata contains all animals that possess a backbone or spinal column. This includes all vertebrate animals such as mammals, birds, reptiles, amphibians, and fish. There are estimated to be around 90,000 species within the Chordata phylum. In addition to the spinal column, some other distinctive features of this group include:
- Presence of a nerve cord running along the back
- Pharyngeal slits or clefts in the pharynx at some point during development
- Muscular tail extending past the anus
- Endostyle, a gland located in the floor of the pharynx
The Chordata phylum contains 3 subgroups or subphyla:
- Cephalochordata – lancelets
- Urochordata – tunicates
- Vertebrata – vertebrates
The Snowy Egret belongs to the Vertebrata subphylum, as do all birds, mammals, reptiles, amphibians, and fish. This diverse group contains an estimated 67,000 species, making it the largest subphylum of animals.
Vertebrata Subphylum
Animals in the Vertebrata subphylum have a skeletal system comprised of a backbone made up of articulated vertebrae. This provides rigid internal support. Other characteristics include:
- Well-developed brain enclosed in protective cranium
- Complex sensory organs like eyes and ears
- Advanced nervous system
- Endoskeleton made of bone or cartilage
- Closed circulatory system with heart and major blood vessels
- Most have jaws, paired appendages, and external sex organs
There are 9 classes within the Vertebrata subphylum:
- Mammalia – mammals
- Reptilia – reptiles
- Aves – birds
- Amphibia – amphibians
- Actinopterygii – ray-finned fish
- Chondrichthyes – cartilaginous fish
- Myxini – hagfish
- Petromyzontida – lampreys
- Sarcopterygii – lobe-finned fish
Based on these classes, we can now say conclusively that the Snowy Egret belongs to the class Aves, which consists of all bird species.
Aves Class
The class Aves includes modern birds as well as archaic or primordial birds. There are estimated to be around 10,000 – 18,000 species alive today. Features that distinguish them include:
- Feathers
- Toothless beak
- Wings for flight
- Lightweight skeleton
- High metabolic rate
- Four-chambered heart
- Hard-shelled eggs with large yolk
Within the Aves class are 2 subclasses – Archaeornithes and Neornithes. The Archaeornithes contains the primitive and now-extinct ancient birds. The Snowy Egret falls into the subclass Neornithes, which represents all modern living birds.
Neornithes Subclass
The Neornithes subclass is comprised of over 10,000 species that span all the birds living today. There are many orders within this diverse group, reflecting the wide range of diets, habitats, sizes, and forms of modern birds. Some orders found in the Neornithes include:
- Anseriformes – ducks, geese, swans
- Galliformes – gamebirds like grouse, turkeys, chicken
- Procellariiformes – albatrosses, petrels
- Pelecaniformes – pelicans, herons
- Accipitriformes – eagles, hawks, vultures
- Charadriiformes – gulls, auks, shorebirds
- Strigiformes – owls
- Passeriformes – perching birds like warblers, finches
The Snowy Egret belongs to the order Pelecaniformes, which includes pelicans, herons, egrets, ibises, and spoonbills.
Pelecaniformes Order
Birds in the order Pelecaniformes are waterbirds that have webbed feet and long bills used for fishing. There are about 66 species divided into 6 families:
- Pelecanidae – pelicans
- Ardeidae – herons, egrets, bitterns
- Threskiornithidae – ibises, spoonbills
- Balaenicipitidae – shoebill
- Scopidae – hamerkop
- Phaethontidae – tropicbirds
The Snowy Egret is a member of the Ardeidae family, which are freshwater and coastal marsh birds characterized by long legs, necks, and bills.
Ardeidae Family
The family Ardeidae contains 64 species of medium to large wading birds with long necks and legs. They frequent wetlands and hunt for fish, amphibians, or other small animals by standing still or slowly stalking through shallow water. Besides herons and egrets, some other birds in this family include:
- Bitterns
- Night herons
- Boat-billed herons
There are generally 4 groupings or genera within Ardeidae:
- Ardea – great blue heron, grey heron
- Egretta – typical small white egrets
- Bubulcus – cattle egrets
- Butorides – green herons, striated herons
This finally brings us to the genus Egretta, which includes the Snowy Egret.
Egretta Genus
The genus Egretta contains the medium to small white herons and egrets. There are approximately 12 species worldwide, including:
Common Name | Scientific Name |
---|---|
Snowy Egret | Egretta thula |
Little Egret | Egretta garzetta |
Reddish Egret | Egretta rufescens |
Intermediate Egret | Egretta intermedia |
Chinese Egret | Egretta eulophotes |
These small herons all share similar plumage coloration and morphology. Most are white with some black accents on the wings and legs. They have long, pointed bills adapted to spearing fish and thin necks for quick strikes.
Snowy Egret Classification
In summary, here is the full classification of the Snowy Egret from kingdom to species:
- Kingdom: Animalia
- Phylum: Chordata
- Subphylum: Vertebrata
- Class: Aves
- Subclass: Neornithes
- Order: Pelecaniformes
- Family: Ardeidae
- Genus: Egretta
- Species: Egretta thula
So in summary, the Snowy Egret belongs to the phylum Chordata, in the subphylum Vertebrata.
Conclusion
Through following the taxonomic classification system from broad kingdom down to specific species, we can determine that the Snowy Egret belongs to the phylum Chordata. All birds fall into this phylum of vertebrate animals that possess a spinal column. The Snowy Egret can be narrowed down step-by-step based on its unique traits: order Pelecaniformes for its waterbird ecology, family Ardeidae for its heron morphology and hunting behavior, genus Egretta for its white plumage and thin build, and finally species Egretta thula for its distinctive yellow feet and ornamental breeding plumes.
Understanding where a species fits evolutionarily provides insight into its biology, physiology, and ecology. Identifying the phylum reveals shared traits and ancestry with other organisms. Placing the Snowy Egret in phylum Chordata provides a wealth of information about this elegant marsh bird’s structure, function, and lifestyle based on the characteristics of all vertebrates. Taxonomic classification thus creates a framework for understanding biodiversity and how species are related to one another on the tree of life.