Rather large, wholly dark petrel. Breeds in New Zealand and ranges across the temperate South Pacific to Chile, where it is uncommon to locally fairly common in the Humboldt Current and fjords. Often found with much commoner, but very similar White-chinned Petrel and is not easily identified unless distinct black bill tip of Westland can be seen (White-chinned has pale bill tip). Slightly smaller Parkinson’s Petrel looks very similar to Westland, but favors warmer tropical and subtropical waters and has a smaller, more rounded head and slightly slimmer bill.