Week 8 - sample lab exam question

WEEK 8 - SAMPLE LAB EXAM QUESTION

QUESTION:

Look at the White Crossbill at Demonstration 1.
1. Would this species of bird be able to forage on sunflower seeds?
2. Name the food source commonly exploited by this bird species.
3. Note that the top mandible of the beak crosses to the left over the lower mandible. Can you suggest how foraging behavior would differ if the mandibles crossed in the opposite in the opposite direction?
  
  Compare the Evening Grosbeak and the Pine Siskin.
4. Name one food resource that each could exploit that would not be available to the other bird.
ANSWER:
1. Unlikely. it would be difficult to pick up a sunflower seed with a crossbill - like picking up an object with bent scissors.
2. Pine cones
3. Any plausible answer sugggesting that the mechanics of foraging would be modified would be acceptable. Possible answer - birds would forage counterclockwise around the cone with bill crossed one way, clockwise with bill crossed the other.
4. Pine siskin can extract seeds from catkins and cone scales. Evening grosbeak can crack big, hard seeds.

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