RULE: Sooty Tern

<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
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 = {White, or pale (grayish-white)} OR {Unknown} AND
What colour was the THROAT = {White, or pale (grayish-white)} OR {Unknown} AND
What colour was the BILL = {Brown, or chestnut (reddish-brown)} OR {Gray, or blue-gray} OR {Black, purple, or dark} OR {Unknown} AND
<What SHAPE was the BILL> = {Straight and thick} OR {Unknown} AND
<What LENGTH was the BILL> = {Short} OR {Medium} OR {Long} OR {Unknown} AND
What colour were the EYES = {Brown or blackish brown} OR {Black or dark gray} OR {Unknown} AND
What colour was the TOP of HEAD = {White, or pale (grayish-white)} OR {Black, purple, or dark} OR {Unknown} AND
How BIG was the bird = {Pigeon-sized} OR {Crow-sized} AND
<What TYPE of bird was seen> = {Gull-like, or a Seabird} AND
<WHERE was the bird seen> = {Northeastern Canada or United States}
THEN
Sooty Tern (Confidence: 1)