RULE: Ashy Storm-Petrel

<Question>
Match
{Variable}
Direct Choice
{Variable}
Infered Choice

IF
What colour were the LEGS or FEET = {Brown, or chestnut (reddish-brown)} OR {Gray, or blue-gray} OR {Black, purple, or dark} OR {Unknown} AND
What SHAPE was the TAIL = {Forked} OR {Unknown} AND
Was the RUMP or LOWER BACK light = {No} OR {Unknown} AND
What colour was the BACK = {Brown, or chestnut (reddish-brown)} OR {Gray, or blue-gray} OR {Black, purple, or dark} OR {Unknown} AND
What colour was the BREAST = {Brown, or chestnut (reddish-brown)} OR {Gray, or blue-gray} OR {Black, purple, or dark} OR {Unknown} AND
What colour was the THROAT = {Brown, or chestnut (reddish-brown)} OR {Gray, or blue-gray} OR {Black, purple, or dark} OR {Unknown} AND
What colour was the BILL = {Black, purple, or dark} OR {Unknown} AND
<What SHAPE was the BILL> = {Straight and slender} OR {Straight and thick} OR {Hooked} OR {Unknown} AND
What was the predominant colour of the HEAD = {Brown, or chestnut (reddish-brown)} OR {Gray, or blue-gray} OR {Black, purple, or dark} OR {Unknown} AND
How BIG was the bird = {Sparrow-sized} OR {Robin-sized} AND
<What TYPE of bird was seen> = {Gull-like, or a Seabird} AND
What type of ENVIRONMENT was the bird seen in = {Open ocean; beyond sight of land} AND
<WHERE was the bird seen> = {Southwestern United States} OR {Northwestern Canada or United States}
THEN
Ashy Storm-Petrel (Confidence: 4)