RULE: Common Loon

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

IF
In FLIGHT did the bird display a LIGHT WING STRIPE or PATCH = {No} OR {Unknown} AND
What colour PATTERN if any was on the BACK = {Checkered black and white} OR {Unknown} AND
What colour was the BACK = {White, or pale (grayish-white)} OR {Black, purple, or dark} OR {Unknown} AND
What colour was the THROAT = {Green} OR {Black, purple, or dark} OR {Unknown} AND
What colour was the NECK = {White, or pale (grayish-white)} OR {Green} OR {Black, purple, or dark} OR {Unknown} AND
What colour was the BILL = {Blue} OR {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 slender} OR {Straight and thick} OR {Unknown} AND
<What LENGTH was the BILL> = {Medium} OR {Long} OR {Unknown} AND
What FACIAL or HEAD features were noted if any = {NONE or a PLAIN unmarked FACE} OR {Unknown} AND
What was the predominant colour of the HEAD = {Green} OR {Black, purple, or dark} OR {Unknown} AND
<How BIG was the bird> = {Crow-sized} OR {Goose-sized} OR {Larger than a goose} AND
<What TYPE of bird was seen> = {Duck or Goose-like} AND
WHEN was the bird seen = {Spring} OR {Summer} AND
<WHERE was the bird seen> = {Northeastern Canada or United States} OR {Northwestern Canada or United States}
THEN
Common Loon (Confidence: 7)