Double-crested Cormorant vs. Great Cormorant
Learn to tell the Double-crested Cormorant and Great Cormorant apart on prairie lakes with clear field marks, seasonal cues, and practical tips for patient observation.
Contents
- What is the quickest way to separate a Double-crested Cormorant from a Great Cormorant?
- Field marks to notice first
- Throat patch and face skin
- Body size and shape
- Bill shape
- Plumage and immature birds
- Where and when to look on prairie lakes
- Practical tips for your next outing
- Quick comparison table
- Seasonal changes and patient observation
What is the quickest way to separate a Double-crested Cormorant from a Great Cormorant?
The most reliable difference is the skin around the bill and eye. An adult Double-crested Cormorant shows a bare orange-yellow throat patch that is rounded or slightly squared off, and the yellow skin does not extend behind the eye. A Great Cormorant has a white throat patch that often extends as a white wedge behind the eye, and adults in breeding plumage develop a white thigh patch. Size and bill shape also help: Great Cormorants are larger and heavier, with a thicker, more robust bill, while Double-crested Cormorants are slimmer with a longer, more slender bill.
Field marks to notice first
Throat patch and face skin
On a Double-crested Cormorant, the bare skin at the base of the bill is orange-yellow. The shape is usually rounded and does not reach behind the eye. On a Great Cormorant, the bare skin is white in adults and often forms a wedge that extends behind the eye. Juveniles of both species have duller skin, but the Double-crested still tends to show yellowish tones while young Great Cormorants are whitish on the throat.
Body size and shape
Great Cormorants are noticeably larger and bulkier. A Double-crested Cormorant is about 70–90 cm long with a wingspan of 114–123 cm. A Great Cormorant is about 80–100 cm long and noticeably heavier, with a wingspan of 130–160 cm. In flight, the Great Cormorant appears broader winged and heavier bodied, while the Double-crested appears slimmer and more streamlined.
Bill shape
The Double-crested Cormorant has a slimmer, longer-looking bill that is often described as orange to yellowish at the base and darker at the tip. The Great Cormorant has a stouter, thicker bill with a more prominent hook at the tip. In breeding season, the Great Cormorant may show a small white feather patch near the base of the bill, but this is less obvious than the throat skin.
Plumage and immature birds
Adult Double-crested Cormorants are glossy black with a greenish or bronze sheen. In breeding season, they grow short black or white tufts on the sides of the head, giving them the “double crest.” Adult Great Cormorants are also blackish but often show a white thigh patch in breeding plumage and a broader white throat patch. The sheen is more bronze or purple, less green than the Double-crested.
Immature Double-crested Cormorants are brownish above and pale below, with a pale throat and chest. Young Great Cormorants are also brownish but often have a white belly that contrasts more sharply with the dark breast, and the pale throat may be whiter and extend further onto the face. The white wedge behind the eye is often visible even on young Great Cormorants, while young Double-crested Cormorants have a more rounded pale throat with yellowish tones.
Where and when to look on prairie lakes
On prairie lakes, Double-crested Cormorants are the expected species during the warmer months. They arrive in spring, nest in colonies on islands or dead trees, and leave by late fall. Great Cormorants are rare visitors, mostly seen in late fall or winter on large lakes or reservoirs, often along rocky shores. During migration, both species may fly in lines or V-formations over open water, but size and face pattern remain the key clues.
Practical tips for your next outing
- Carry binoculars that are comfortable for long looks; cormorants often perch far out on snags or buoys.
- Look first at the face and throat skin, then size, then bill shape and plumage details.
- Watch for behavior: cormorants often spread their wings to dry, which gives a good view of the body size and plumage pattern.
- In fall and winter, scan large lakes after cold fronts; Great Cormorants are more likely then, but Double-crested can linger into November.
- Keep a field notebook and sketch the face pattern and relative size. Notes help you learn the subtle differences faster than photos alone.
- Respect nesting colonies and roost sites; observe from a distance with a spotting scope.
Quick comparison table
| Feature | Double-crested Cormorant | Great Cormorant |
|---|---|---|
| Throat patch | Orange-yellow, rounded, not behind eye | White, often extends behind eye |
| Body size | 70–90 cm; wingspan 114–123 cm | 80–100 cm; wingspan 130–160 cm |
| Bill shape | Slender, longer, orange base | Stout, thick, hooked, dark with pale base |
| Breeding plumage | Double crest of black or white tufts | White thigh patch, broad white throat |
| Immatures | Brownish, pale throat with yellow tint | Brownish, white belly, pale face with white wedge |
| Status on prairie lakes | Common summer breeding bird | Rare fall/winter visitor |
Seasonal changes and patient observation
In spring, Double-crested Cormorants are in full breeding dress, and the crests are easiest to see. Great Cormorants are mostly absent from prairie lakes then. In late September through November, watch for Great Cormorants among flocks of Double-crested. The white face and thigh patch, if present, stand out even at a distance. Winter sightings require open water; check below dams or warm water outflows. Patient observation over time will train your eye to separate size, face pattern, and bill shape almost automatically. Every careful look adds to your field notes and deepens your connection to these wild, wind-swept places.