Species Hierarchy
Common name: GREBE - WESTERN

Species Info:

This lifeform is found in the Pacific States and Provinces of North America. The white color will help identify this lifeform.

Western Grebe (Aechmophorus occidentalis) species complex breeds from Alaska to Colorado to southern California. Their winter range is from Alaska to Mexico.

These are large grebes up to twenty-eight inches in length. The swan-like neck and black color above and white color below help identify these birds.  

The complex has recently been split into two different species:

      Western Grebe (A. occidentalis)
      Clark's Grebe (A. clarkii)

While very similar, they can be separated by the black and white pattern on the head. In the Western Grebe the black head coloration extends below the eye. In the Clark's grebe it does not.

The distribution for these two species is combined in the Christmas bird counts. However, the Clark's Grebe is found more towards the northeastern part of the combined range.

Grebe order (Podicipediformes) contains a single family
(Podicipedidae). Although the Grebes and Loons are frequently
combined, these are two rather divergent groups of birds. Grebes
are usually fresh water species of water birds with a somewhat
duck-like appearance. However, their smaller size, narrow bill
and long neck help separate them from the ducks. The feet of the
grebe are mounted far back on its body and are useful for
swimming. Their tails are almost nonexistent. There are 20
different species of grebes known, and six of these species are
found in North America.

Aves contains about 8,650 different species of living birds known to science. Each year about one new species is discovered in some remote rain forest or remote island. In addition, scientists have been raising many subspecies to full species status which may raise the species count to 10,000.

However, each year about one species goes extinct. The rate of extinction is increasing, and the rate of new discovery is decreasing, so that the number of bird species will soon begin to decline rapidly. Although different taxonomists would organize the birds differently, there are approximately twenty-seven orders of birds. These orders are broken down into about one hundred and fifty-five different families.

Recent research of the genetic structure of some of the shore birds and owls would indicate that the present organization of orders and families should have some modification.

The birds are a worldwide group of animals that are characterized by having the front limbs modified into wings that are used for flying. Perhaps the most unique feature of the birds is the feathers. These feathers are made up of a central support called a quill and a series of small filaments that are hooked together as barbs.

For many years it was believed that Archaeopteryx discovered in Bavaria was the oldest bird from about 150 million years ago.  However, in l986, Sankar Chattterjee, a Texas paleontologist, reportedly discovered a bird in the genus Protoavis that lived about 225 million years ago.

Backboned Animals (Phylum Chordata) are the most advanced group of animals on earth. These animals are characterized by having a spinal cord or backbone. Most members have a clearly defined brain that controls the organism through a spinal cord. Fish, amphibians, reptiles, birds, and mammals are in this phylum.

Currently, some taxonomists believe that the fish should be divided into two groups (sharks and regular fishes) and that there are some other primitive groups in the phylum such as hagfish or lampreys.

Animal Kingdom contains numerous organisms that feed on other animals or plants. Included in the animal kingdom are the lower marine invertebrates such as sponges and corals, the jointed legged animals such as insects and spiders, and the backboned animals such as fish, amphibians, reptiles, birds, and mammals.


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