Leach's Storm-Petrel vs Matsudaira's Storm-Petrel

In short

Leach's Storm-Petrel and Matsudaira's Storm-Petrel can be challenging to differentiate, but key differences in tail shape and plumage tone are helpful. Leach's has a forked tail and a more uniform dark brown plumage, while Matsudaira's features a slightly wedge-shaped tail and paler underwing coverts.

Identification tips

• Tail shape: Leach's has a forked tail; Matsudaira's is slightly wedge-shaped.
• Plumage tone: Look for paler underwing coverts on Matsudaira's.
• Geographic range: Consider location; Matsudaira's is more likely in the Northwest Pacific.
• Flight pattern: Note any differences in steadiness and hovering behavior.

Size

Both species are similar in size, with Matsudaira's Storm-Petrel being slightly larger.

Plumage

Leach's Storm-Petrel has a uniform dark brown plumage with a distinct white rump. Matsudaira's Storm-Petrel also has a white rump but shows paler underwing coverts and a slightly darker overall appearance.

Behaviour

Both species exhibit similar flight patterns typical of storm-petrels, with erratic and buoyant flight. Leach's is often seen hovering and gliding, while Matsudaira's may appear steadier in flight.

Habitat

Leach's Storm-Petrel is more widespread in the North Atlantic and Pacific, often seen offshore. Matsudaira's Storm-Petrel is more restricted to the Northwest Pacific, particularly around Japan.

Voice

Vocalizations are not a reliable field mark as both species are generally silent at sea.