The definition of species has changed just in my lifetime. This is the previous definition of species:
"If two animals can mate and produce fertile offspring then they are the same species."
That definition does not work for evolutionists any more because there would not be enough species to "prove" evolution. Now, they give a new species name to every little variation in a plant or animal.
For example, all dogs are the same species, Canis familiaris. If the various breeds of dog were wild and not domesticated they would be labeled as different species. For example, Poodles, St Bernards, Great Danes, German Shepherds and Old English Sheepdogs they would all be labeled as different species because they look so different.
But, wolves and coyotes, which can both produce fertile offspring with dogs, are given many species names for minor differences. For example, according to the National Audubon Society Field Guide to North American Mammals the Grey Wolf (Canis lupus) and the Red Wolf (Canis rufus) are called different species. In reality, wolves and coyotes are just another breed of dog.
Here is another example. Ornithology is the study of birds. Bird identification field guides for North America (where I live) list birds in the agreed upon evolutionary order per the American Ornithologists' Union. (See below). Ornithologists give the label "species" to very minor differences in birds. A sparrow with a different sized spot or streak on the breast or around the eye is labeled as a different species.
I'm a bird watcher. There are many different "species" of sparrows. Some are extremely difficult to tell apart and you have to see them several days in a row before you can see that extra spot or stripe on the breast or around the eye to positively identify it.
Creationists believe that God created the basic types of plants and animals, and then genetic variation went on from there. God made the basic types of birds including: hummingbird, woodpecker, parrot, pigeon, sparrow, duck, and so forth. Each type had a lot of capacity for genetic variability as we see in dogs.
The actual bird list of the American Ornithological Union is very long so bird books give a index of the major groups of birds, such as the list below from Stokes Field Guide to Birds: Eastern RegionColor Tab Index
Facing the front and back covers is the Color Tab Index to Bird Groups. This provides access to the birds by groups - heronlike birds, shorebirds, woodpeckers, sparrows, and so forth. The color tabs are a fast way to automatically turn to the right portion of the guide. In addition, this index and the Species Accounts are arranged in phylogenetic order, that is, according to their believed evolutionary relationships, thus familiarizing all users with the only order of birds generally agreed upon by scientists and birders in North America.
Species, Names, Order
All regularly occurring species within the range of the guide are included. Their scientific and common names and order are in accordance with the July 1995 supplement to the 6th edition of the American Ornithological Union Checklist of North American Birds.
This book also lists a "Quick Guide" listing the major groups of birds:
Quick Guide to the Most Common Birds
Seabirds - Loons, Grebes, Shearwaters, Pelicans, Cormorants
Heronlike Birds - Bitterns, Herons, Egrets, Ibises
Swans, Geese, Ducks - Whistling-Ducks, Swans, Geese, Ducks
Hawklike Birds-Osprey, Kites, Eagles, Hawks, Falcons
Chickenlike Birds - Pheasant, Grouse, Turkey, Quail
Marsh Birds - Rails, Gallinule, Moorhen, Coot, plus Cranes
Shorebirds - Plovers, Stilt. Avocet, Sandpipers, Dowitchers, Phalaropes
Gull-like Birds -Jaegers, Gulls, Terns, Skimmer, plus Alcids
Pigeonlike Birds - Pigeon, Doves
Owls and Other Nocturnal Birds - Owls, Nighthawks, Whip-poor-will
Swift, Hummingbirds -Swift, Hummingbirds, plus Kingfishers
Woodpeckers - Woodpeckers, Sapsucker, Flicker
Flycatchers - Flycatchers, Phoebes, Kingbirds
Shrikes, Vireos - Shrikes, Vireos
Jays, Crows - Jays, Crows, Ravens
Swallows - Martin, Swallows
Chickadees, Nuthatches, Wrens - Chickadees, Titmice, Nuthatches, Wrens
Thrushes, Mimics - Bluebird, Thrushes, Robin, Catbird, Mockingbird, Thrashers
Warblers - Warblers, Parula, Redstart, Ovenbird, Waterthrushes, Chat
Tanagers, Grosbeaks, Buntings-Tanagers, Cardinal, Grosbeaks, Buntings
Sparrows - Towhees, Sparrows Junco, Longspurs
Blackbirds, Orioles - Blackbirds, Grackles, Cowbirds; Orioles
Finches - Finches Crossbills, Redpolls, Goldfinches
These are all the categories of birds in North America. All of the birds in North America are in one of the groups above. All of the groups are distinct categories. However, evolution is said to be a very slow progression of gradual change from one type of animal or plant to another type of animal or plant. And yet even just among birds there is not a gradual change between species. For instance, hummingbirds and woodpeckers are like no other birds. They are very specialized. There is a large gap between hummingbirds and all other birds and there is a large gap between woodpeckers and all other birds.
There is not evidence of a gradual progression of minute changes from or to either of them from or to any other bird either in the fossil record or in live birds.
What the examination of the different groups of birds does show is that woodpeckers, hummingbirds and all other birds are separate and distinct groups. What the examination of birds shows is that birds were created by God.