Questions · Taxonomy
Are Ravens Related to Crows?
Taxonomy, genus Corvus, and what "related" means
[science] Yes — ravens and crows are both in genus Corvus, making them closely related. The Common Raven (Corvus corax) and Carrion Crow (Corvus corone) are congeners — the same genus, different species — like wolves and dogs are both Canis. They are distinct species but share a more recent common ancestor than either shares with other corvid genera (jays, magpies, nutcrackers).
Taxonomy: The Corvidae
[science]
- Family Corvidae: ~120 species worldwide — crows, ravens, rooks, jackdaws, jays, magpies, choughs, nutcrackers, and treepies
- Genus Corvus: ~45 species — includes all species commonly called ravens, crows, rooks, and jackdaws
- Common Raven: Corvus corax
- Carrion Crow: Corvus corone
- American Crow: Corvus brachyrhynchos
- Rook: Corvus frugilegus
- Jackdaw: Coloeus monedula (sometimes Corvus monedula)
All members of genus Corvus share a more recent common ancestor with each other than with any member of another genus.1
What "Species" Means Here
[science] Ravens and crows are classified as separate species because they:
- Differ consistently in morphology (size, structure, bill shape)
- Have distinct vocalisations
- Occupy different ecological niches (partly)
- Do not interbreed in the wild (they are reproductively isolated in practice, though hybridisation has not been rigorously tested in all pairs)
The Common Raven is roughly 2–4× the mass of a Carrion Crow — a substantial size difference. Despite sharing the same genus, they are not interchangeable in terms of ecology or behaviour.1
Within-Genus Diversity in Corvus
[science] Genus Corvus spans an enormous range of body sizes and habitats — it is one of the most species-rich and ecologically diverse bird genera:
- Smallest: Jackdaw (C. monedula) at ~220 g
- Largest: Thick-billed Raven (C. crassirostris) and Common Raven (C. corax) at up to ~1,600 g
- Range: Every continent except South America and Antarctica
- Habitats: Desert, arctic tundra, tropical forest, alpine, coastal — virtually every terrestrial biome
The genus demonstrates that "crow" and "raven" are common-name categories that do not map cleanly onto evolutionary sub-groups within Corvus.1,2
Evolutionary Relationships: Phylogeny of Corvus
[science] Molecular phylogenetic studies have shown that genus Corvus likely originated in Australia or the Indo-Pacific and diversified rapidly. Some key findings:
- The Common Raven (C. corax) is not a single cleanly-defined evolutionary lineage — it shows deep mitochondrial divergence between populations (North American "clades" diverge substantially from each other; more than from some other Corvus species)
- This suggests the Common Raven as currently defined may be a species complex — a group of populations that look similar but have deep evolutionary divergence
- "Raven" is a size/ecological grade rather than a monophyletic group — large Corvus have evolved multiple times
The taxonomy of Corvus continues to be revised as genetic data accumulates.2
Frequently Asked Questions
Are ravens related to crows?
Yes — ravens and crows are closely related. Both are in the genus Corvus (family Corvidae), which contains approximately 45 species including ravens, crows, jackdaws, rooks, and others. The Common Raven (Corvus corax) and Carrion Crow (Corvus corone) are congeners — members of the same genus — the equivalent relationship to wolves and domestic dogs being in the genus Canis. They are distinct species that last shared a common ancestor millions of years ago, but share more recent ancestry than either does with, say, a Blue Jay.
Sources
- Madge, S. & Burn, H. (1994). Crows and Jays. Christopher Helm. — taxonomy and species accounts for genus Corvus.
- Boarman, W. I. & Heinrich, B. (1999). Common Raven (Corvus corax). The Birds of North America, No. 476. — phylogenetics of Corvus corax.
[science] field-guide and species-account data