For every species listed in this guide I have attempted to answer some basic questions. When I was writing these sections, however, I found myself lacking some fundamental biological facts which created a number of questions. The answers to some of these questions are listed below. While they are not as interesting reading as are the sections on the birds and mammals, I offer them here to those of you wanting more background on the categories of information presented.

What order are the animals listed in?

The animals in most wildlife field guides are arranged in a particular order, but what is the criteria for putting them in that order? Why, for instance, are the ducks usually listed before smaller birds like sparrows? Why are foxes always found in the same section as coyotes?

Animals are often arranged in a sequence that is based on their natural, or evolutionary, relationships. Scientists have created a system in which all animals are classified by systematically placing them in groups and then arranging them according to individual species. For example, herons evolved before finches so they are usually listed before finches. Opossums evolved before most mammals alive today and so are usually listed before all the other mammals. Most field guide authors take liberties with this system and often arrange the animals according to additional criteria.

I have based the arrangement of birds and mammals in this project according to two authorities: the A.O.U. Check-list of North American Birds, 1983 published by the American Ornithologists Union and the Revised Checklist of North American Mammals North of Mexico, 1991 published by a respected group of mammalogists from Texas Tech University. Both of these sources give accepted names, spellings, capitalizations, punctuation, and order of listing.

However, the A.O.U. Checklist uses a different system for listing the birds than is used in the Checklist of North American Mammals. If the evolutionary relationships are not well established within each bird family, the A.O.U. Checklist arranges the birds northern-most first and southern-most last. The mammals Checklist is arranged according to evolutionary relationships between the families, but the individual species are simply listed alphabetically by scientific name.

Ornithology journals usually capitalize common bird names while mammalogy journals avoid this convention for mammal names. For consistency, I have written all animal names in lower case.

Why does each animal have so many common names?

I have included a list of names under "Also known as" for each animal. Most of these names originated in different regions throughout the entire range of the animal. So while the mountain lion found in Oregon is the same species as the one found in Florida, it would seem strange for Oregonians to refer to the mountain lion as a Florida panther, which is what Floridans call it. This is how one species can get so many names.

Some names reflect the color or physical variations that occur in the different subspecies, which is why the northern flicker has both the common names yellow-shafted flicker and red-shafted flicker. In one part of its range the northern flicker has red on the undersurfaces of it wings and in another part of its range it has yellow. To make communication and research easier (no kidding), scientists have developed a hierarchical system of organizing and classifying all living things.

What is the biological system of classification?

All living things are broken down into a ranking of classes ending with the scientific name as the most specific (species) designation. The classification scheme (offically known as "taxonomic classification") used by scientists includes the following components and ranking:

Kingdom
Phylum
Class
Order
Family
Genus
Species

Each species of animal has a designated name for each one of these categories. For example, the complete classifications of the American robin and the coyote are:

**	American Robin	Coyote
Kingdom Phylum Class Order Family Genus Species	Animalia Chordata Aves Passeriformes Turdidae Turdus migratorius	Animalia Chordata Mammalia Carnivora Canidae Canis latrans

What is a scientific name?

The problem with common names, as you can see in the discussion above, is that they tend to vary with region. The scientific name was developed to have one standard name for each species. Although scientific names can sometimes vary, they do so much less frequently than common names. For instance, the bobcat is known both as Felis rufus and Lynx rufus, depending upon what source you consult. However, agreement on the scientific names for most animals does exist.

A scientific name is made up of a genus name and a specific, or species, name. The scientific name for the American Robin, as seen above, is Turdus migratorius. The genus name is Turdus and the species name is migratorius. Most scientific names are made up of either Latin or Greek words, but some words are "Latinized," in other words, they are made to sound like they are Latin. For example, a name like American becomes americanus, Canada becomes canadensis, Steller becomes stelleri, and so on. Scientific names are usually written in italics with the genus name capitalized and the species name entirely in lower case. Whenever a species is discussed, it is always referred to by both the genus name and the species name. I have listed all of the scientific names for the animals listed in this project with their pronunciations and meanings. Hopefully, knowing what they mean and how to say them will make them a little less intimidating.

Scientific names often describe the animal in some way and I have translated the scientific name into an understandable "phrase," rather than just giving the textbook definition. I believe it is easier to remember the scientific name for the bald eagle (Haliaeetus leucocephalus) when you know it means "white-headed sea eagle" rather than knowing that Haliaeetus means "sea eagle and that leucocephalus means "white-headed." Creating a phrase like this for every scientific name sometimes borders on the ridiculous. For example, the striped skunk is "smells bad, smells bad" and the badger "looks like a badger, badger." Nevertheless, I believe that remembering the scientific name in this manner to be more "fun" and less intimidating than simply knowing the literal translation.

What is a species?

All living species have arisen from a preexisting, now extinct species. Several different species can have certain similarities indicating they evolved from a common ancestor. This explains, in part, how the biological classification was developed. A species is defined as "a living population in nature made up of individuals that have about the same structure, size, color, behavior, and habitat, and breed with each other rather than with members of other groups," (Welty and Baptista 1988). Chambers Biology Dictionary defines a species as "A group of individuals that actually or potentially interbreed with each other but not with other such groups."

As with many things in life, textbook definitions aren't true 100% of the time. Although a species is defined as animals that only breed among themselves, crossbreeding sometimes occur. This is how we get wolf-dogs, coyote-dogs, mules and thousands of other variations. These variations are exceptions to the rules, however, and most of the time their offspring cannot reproduce themselves.

What is a subspecies?

Within each classification of species, certain variations can exist that make calling them all one species imprecise. Therefore, scientists have divided species into subgroups according to their physical appearance and geographic location. Not all species are divided into subspecies and the designation is often a matter of debate.

As I write, the Pacific Northwest is the middle of one of the biggest biological and political controversies of all time and it is centered around a rather meek, mild mannered bird: the northern spotted owl. The northern spotted owl is a subspecies of the spotted owl. When a subspecies is classified, a third distinguishing Latin or Greek name is applied to the scientific name. The spotted owl's scientific name is Strix occidentalis and the northern spotted owl's scientific name is Strix occidentalis caurina. When several subspecies are being discussed the genus and species names are usually abbreviated so that the subspecies designation looks like S.o. caurina. The only real variation between subspecies is that they have certain differences that evolved from living in one isolated region for a long period of time. Being in a different environment from other members of their species has caused them to develop a different set of adaptations specific to their region.

Take humans, for example. We are all the same species, Homo sapiens, but we sometimes look very different. While the designation "subspecies" is not used, we often refer to human variations being a result of race. There are Blacks, Orientals, Caucasians, American Indians, etc. All of these differences originally came about as a result of geographic separation, we evolved to be better adapted to our surroundings and, because we didn't have planes, trains or freeways at that time, we were isolated from one another. We only passed on our newly adapted traits to offspring that continued to live in the same location.

Now days we have the ability to travel virtually anywhere in the world and these differences are slowly becoming less definable, as well as unimportant. There is also no reason to designate humans as subspecies since biologically we all have the same characteristics, qualities, and abilities. However, subspecies of animals can be so different from one another that simply referring to them as one species isn't accurate. If left up to nature, a subspecies would probably evolve into a new species given a (very) long period of time.

Therefore, when a subspecies of animal is discussed it refers to a special grouping within a species that has usually resulted from a geographic separation. For this reason, I have often grouped the "Where they are located?" question with the "How many subspecies are there?" question for some of the animals. This was done when there were relatively few subspecies. I have only listed the North American subspecies and ranges for the animals.

How long do animals live?

There are many problems with trying to answer a question like this accurately. It is only through banding a bird or mammal at a known age and finding it after it has died that it is possible to determine how long it lived. To generalize this to an entire species is a big step. Many examples must be retrieved to determine an accurate lifespan and this is difficult to do. Sometimes the age of a mammal may be determined by their teeth but this method is not accurate for all species.

To make things even more confusing, most animals are capable of living much longer in captivity than in the wild. For instance, the longest recorded lifespan for a bald eagle in the wild is 21 years, in captivity it is 48 years. The stress and hardship an animal endures in the wild takes quite a toll on its health, something that animals in captivity avoid. To further complicate the matter, when you refer to an "average" lifespan do you include every animal born? For most animals, over 50% of the newborns die within their first year. If you include all of these into an "average" it becomes very skewed towards a short lifespan. For example, one study found that 77% of newborn wood ducks died in their first year. Thus their "average" lifespan becomes a little over one year. Yet one wood duck lived to be over 22 years old, a little older than one would expect for such a short lifespan.

Most lifespans reported in the biological literature don't fully explain how the "average" was calculated and so the figures given in this project should be read with that consideration in mind. All of the lifespans presented in this project refer to animals living in the wild, unless it specifically mentions that the ages came from captive animals. In general, the bigger the bird the longer the lifespan, although there are exceptions (Lindstedt and Calder 1976). I found no such written generalizations for mammals, however, but they seem to follow this same pattern.