Not really. For example blue and golden winged warblers are separate species, but in the zone where they overlap, they produce fertile F1 hybrid offspring. 'Species' is one of those categorizations that resists being defined too narrowly.
1 And it came to pass, when men began to multiply on the face of the earth, and daughters were born unto them,
2 That the sons of God saw the daughters of men that they were fair; and they took them wives of all which they chose.
Not really. For example blue and golden winged warblers are separate species, but in the zone where they overlap, they produce fertile F1 hybrid offspring. 'Species' is one of those categorizations that resists being defined too narrowly.
"Species" is a man-made definition with certain man-made criteria. The blue and golden winged warblers may have been classified as different species by an ornithologist who believed them to be different species. Mother Nature subsequently proved the ornothologist wrong.
The warblers in question meet the criteria for:
Subspeies = a taxonomic rank immediately below species, indicating a group of organisms that is geographically isolated from and may display some morphological differences from other populations of a species, but is nevertheless able to interbreed with other such groups within the species where their ranges overlap.