Understanding Taxonomy

Understanding Taxonomy

Understanding Taxonomy
In 1758 a man named Carolus Linnaeus developed a classification system for all animals. He divided the animal Kingdom into groups that each had things in common. Then he divided those groups into smaller groups that had even more things in common. When he finally finished, there were seven levels in his system. At the lowest level is the species. His scientific classification system is still used today.
These seven levels are shown below. Here is how scientists classify an American Robin:
Level Name Description Kingdom Animalia Animals Phylum Chordata Animals with backbones Class Aves Animals called Birds Order Passeriformes Birds that perch Family Turdidae All Thrushes Genus Turdus Similar Thrushes Species Turdus migratorius American Robin

Notice that the species has two names. The names are in Latin. The first name is the Genus and the second is another name that often describes a prominent feature of the bird. The second name may also be a person's name -- often the name of the ornithologist that first discovered the bird.
Scientists sometimes will talk about "races" or "tribes" of one species. Human Beings are a species but there are many races of humans. The same is true for birds. When you go birding you may notice that some birds, such as the Yellow-rumped Warbler, look different in the East than the same species does in the West. Different races of the same species often are separated geographically.
We are interested in a class of animals with backbones known as birds. Birds have feathers and lay eggs. All birds have wings. However, not all birds can fly. The Ostrich is too heavy to fly. Penguins use their wings to swim, instead of to fly. A few birds "forgot" how to fly because they spent all their time on the ground. After many centuries, their ancestors had evolved to the point where they were unable to fly. Often these birds live on remote islands in the Pacific Ocean. They are vulnerable to introduced animals and snakes.
As scientists learn more about birds, they are able to arrange the 9700+ species of birds into the correct Order, Family and Genus. There is a surprising amount of debate about some birds. Are they really a species or not? They may actually be a race of a similar species in the same genus. For example, the Baltimore Oriole is not a species any more. About twenty years ago scientists decided it was the same bird as the Bullock's Oriole. The Baltimore Oriole lives in the Eastern United States and the Bullock's Oriole lives in the Western United States. Both birds are now called the Northern Oriole. Of course, just the opposite can happen. A bird called the Rosy Finch was recently declared to be THREE different birds! Scientists can change their minds after more evidence is produced. For example, many scientists believe that the Northern Oriole may soon be split back into two separate species again!
Combining two apparent species into just one new species is called "lumping." Separating a species into two or more species is called "splitting." Birders like it when scientists decide to "split" a bird because then there are more species of birds to see. Their "Life List" of birds may go up because they had already seen both "races" of the old species. There seems to be a trend today toward splitting birds. This is because better methods of research are now available to examine birds at the microscopic level.
Today there are many scientists investigating birds. They work at places like The Academy of Natural Sciences in Philadelphia or Cornell Laboratory of Ornithology or Pennsylvania State University or Louisiana State University. It is certain that their work will make bird species appear and disappear as they continue lumping and splitting. That is why a computerized list of the world's birds makes more sense than a printed list in a book. You can update your computer and always have the best, most current classification list possible. A book listing all the birds of the world is obsolete by the time you read it. At least that is my unbiased opinion.
Scientific classification is undergoing a big change. Dr. Charles G. Sibley has been doing research for over twenty years using DNA from bird's blood. He and his associates suggested a new way to classify the 9700+ birds of the world. His new system is called the Sibley/Ahlquist/Monroe classification or SAM for short. Dr. Sibley discovered that some species are more closely related than anyone though. He also rearranged the Orders and Families in a way that is quite unexpected. Additional research being done today is proving that Dr. Sibley is probably right. The SAM classification seems, to many scientists, to be better than the one used for the last 100 years. However, most bird books and checklists have not been changed yet to show the new SAM classification. Scientists want to be very sure this new classification is better than the traditional classification before they make an official change.
1996 Changes to AOU checklist

Questions or comments?
Birding Related: ornithologist@birder.com
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Technical: webmaster@birder.com




	Understanding Taxonomy In 1758 a man named Carolus Linnaeus developed a classification system for all animals. He divided the animal Kingdom into groups that each had things in common. Then he divided those groups into smaller groups that had even more things in common. When he finally finished, there were seven levels in his system. At the lowest level is the species. His scientific classification system is still used today. These seven levels are shown below. Here is how scientists classify an American Robin: Level Name Description Kingdom Animalia Animals Phylum Chordata Animals with backbones Class Aves Animals called Birds Order Passeriformes Birds that perch Family Turdidae All Thrushes Genus Turdus Similar Thrushes Species Turdus migratorius American Robin Notice that the species has two names. The names are in Latin. The first name is the Genus and the second is another name that often describes a prominent feature of the bird. The second name may also be a person's name -- often the name of the ornithologist that first discovered the bird. Scientists sometimes will talk about "races" or "tribes" of one species. Human Beings are a species but there are many races of humans. The same is true for birds. When you go birding you may notice that some birds, such as the Yellow-rumped Warbler, look different in the East than the same species does in the West. Different races of the same species often are separated geographically. We are interested in a class of animals with backbones known as birds. Birds have feathers and lay eggs. All birds have wings. However, not all birds can fly. The Ostrich is too heavy to fly. Penguins use their wings to swim, instead of to fly. A few birds "forgot" how to fly because they spent all their time on the ground. After many centuries, their ancestors had evolved to the point where they were unable to fly. Often these birds live on remote islands in the Pacific Ocean. They are vulnerable to introduced animals and snakes. As scientists learn more about birds, they are able to arrange the 9700+ species of birds into the correct Order, Family and Genus. There is a surprising amount of debate about some birds. Are they really a species or not? They may actually be a race of a similar species in the same genus. For example, the Baltimore Oriole is not a species any more. About twenty years ago scientists decided it was the same bird as the Bullock's Oriole. The Baltimore Oriole lives in the Eastern United States and the Bullock's Oriole lives in the Western United States. Both birds are now called the Northern Oriole. Of course, just the opposite can happen. A bird called the Rosy Finch was recently declared to be THREE different birds! Scientists can change their minds after more evidence is produced. For example, many scientists believe that the Northern Oriole may soon be split back into two separate species again! Combining two apparent species into just one new species is called "lumping." Separating a species into two or more species is called "splitting." Birders like it when scientists decide to "split" a bird because then there are more species of birds to see. Their "Life List" of birds may go up because they had already seen both "races" of the old species. There seems to be a trend today toward splitting birds. This is because better methods of research are now available to examine birds at the microscopic level. Today there are many scientists investigating birds. They work at places like The Academy of Natural Sciences in Philadelphia or Cornell Laboratory of Ornithology or Pennsylvania State University or Louisiana State University. It is certain that their work will make bird species appear and disappear as they continue lumping and splitting. That is why a computerized list of the world's birds makes more sense than a printed list in a book. You can update your computer and always have the best, most current classification list possible. A book listing all the birds of the world is obsolete by the time you read it. At least that is my unbiased opinion. Scientific classification is undergoing a big change. Dr. Charles G. Sibley has been doing research for over twenty years using DNA from bird's blood. He and his associates suggested a new way to classify the 9700+ birds of the world. His new system is called the Sibley/Ahlquist/Monroe classification or SAM for short. Dr. Sibley discovered that some species are more closely related than anyone though. He also rearranged the Orders and Families in a way that is quite unexpected. Additional research being done today is proving that Dr. Sibley is probably right. The SAM classification seems, to many scientists, to be better than the one used for the last 100 years. However, most bird books and checklists have not been changed yet to show the new SAM classification. Scientists want to be very sure this new classification is better than the traditional classification before they make an official change. 1996 Changes to AOU checklist
Questions or comments? Birding Related: ornithologist@birder.com Advertising: advertising@birder.com Technical: webmaster@birder.com