There are many different kinds of animals (animal species) on earth. Some of them are quite common and adaptable, they can be found in many kinds of habitats and are often able to live in areas that humans have changed substantially, such as in farmlands, neighborhoods, and cities. You've probably seen pigeons in your neighborhood in Michigan, they are an excellent example of a common and adaptable animal species.
Most other animal species are not as common or adaptable as pigeons. There may not be as many of them in any particular area or they may only live in specific areas or kinds of habitats. For example, in the summers Kirtland's warblers live only in specific kinds of pine forest habitats that are found in only a few places in Michigan (in the winter they fly to Bermuda). Because the kinds of habitats that they can live in are so uncommon, these birds have always been somewhat rare. Humans began to cut down the pine forests that Kirtland's warbler's rely on in the 19th century. As a result, these rare birds became even more rare. To keep them from becoming extinct, Kirtland's warblers are protected as an endangered species in Michigan.
Most animal species are not as rare as Kirtland's warblers and not as common as pigeons. Animal species might be fairly common or fairly rare, depending on their particular ecological needs and interactions and the influence of human changes to their habitats and their populations.
To protect animal species and populations, and the habitats they rely on, local, state, and federal (national) governments have laws about how much protection different kinds of animals should get. Each animal (and plant) species is given its own conservation status. Conservation means to actively protect something from damage or loss. The conservation status of an animal will tell you something about how common or rare it is.
These pages help you to explore the animal species in Michigan by their conservation status. Each conservation category page will list Michigan animal species by their status.