Wedge-rumped Storm-Petrel vs Tristram's Storm-Petrel

In short

The Wedge-rumped Storm-Petrel and Tristram's Storm-Petrel are both small seabirds with dark plumage, but they can be distinguished by their tail shape and flight style. The Wedge-rumped Storm-Petrel has a distinctive wedge-shaped tail, while Tristram's Storm-Petrel has a more notched tail. Observing their flight behavior can also aid in identification.

Identification tips

1. Look for the wedge-shaped tail of the Wedge-rumped Storm-Petrel. 2. Note the white rump patch on Wedge-rumped Storm-Petrel, absent in Tristram's. 3. Observe flight style: Wedge-rumped has a fluttering, erratic flight, while Tristram's is more direct. 4. Both species are challenging to identify at sea due to similar size and dark plumage.

Size

Both species are similar in size, typical of small storm-petrels.

Plumage

Wedge-rumped Storm-Petrel has a distinctive white rump patch that contrasts with its otherwise dark plumage, while Tristram's Storm-Petrel is uniformly dark with no contrasting rump patch.

Behaviour

Wedge-rumped Storm-Petrel often exhibits a fluttering flight with frequent changes in direction, whereas Tristram's Storm-Petrel has a more direct and steady flight pattern.

Habitat

Both species are pelagic and are typically found far out at sea, but Wedge-rumped Storm-Petrel may be more frequently observed near breeding colonies on islands.

Voice

Vocalizations are rarely heard at sea, and differences are not well-documented for field identification.