STATE LABORATORY: THE BEAKS OF FINCHES

Featured in Part D of the New York State Regents:

Introduction

• You are going to use different tools to model the beaks of different finches.

• Each beak is different in size and shape. • Successful finches have beaks that correspond

to their food source.

Introduction

• In this laboratory activity you will:1.Learn how structural differences may affect

the survival rate of members of a species2.Simulate competition for resources among

different species of organisms3.See the role of the environment as a selecting

agent

Instructions

• Every lab pair will receive a specific “beak” tool.

• Every tool represents different shapes of beaks of finches.

Procedures: Student Lab Packet, Page 2

1. Examine the different tools provided. Predict which would be best at grasping small seeds. Why?

2. Which “beak” would be the least successful? Why?

3. From this point on, you and your partner will model a finch feeding.

Round 1

• Practice using your beak before the “competition” begins.

• The larger dish represents the island you (as a bird) live on and the food there.

• The small dish represents your finch stomach.• You must get 1 seed at a time from your food

source to your stomach.• Wait to start Round 1. Each partner gets 2,

timed trials. Record your results. Average them.

Live or die?

• If your average was 13 seeds or higher, you SURVIVE! You remain healthy and continue to eat small seeds on your island.

• If your average was 12 seeds or less, you won’t survive, so you must MIGRATE to a new island with larger seeds.

Round 2 – Student Lab Packet, Page 3

• Now, you must compete with other finches!• Check off if you are remaining on your original

island or if you have migrated.• All the small seed eaters will compete at one

island.• All the large seed eaters will compete at a

different island.

Round 3

• Each partner gets 2 timed trials.• Average your seeds collected and record this

on page 3.

• If your average was below 12 or lower, you were unable to survive and are now EXTINCT

Round 3

• Only the remaining finches that are alive will compete.

• Record which island you are feeding at. • Record the number of seeds you ate.

Analysis: Student Lab Packet, Pages 4 & 5

• Answer questions 1 through 4.• #5. See Data table on page 8.

Analysis Questions on p. 4

1. Describe why your tool did NOT work2. Claws, speed, size, sight, hearing, smell3. Beak could curve, could be fully closed,

pointy tip, longer beak, beak fully shuts4. Beans were a different size and shape.

Certain beaks were able to survive in the new environment

Analysis Questions p.4

1. Describe what was bad about your tool2. Size, strength, speed, camouflage,

experience gathering food3. Curved beak to scoop food, narrower tip to

pinch food.4. The large seeds were easier to grab because

some beaks were better adapted to the new food source.

Analysis Questions p. 5• 6. No, because when you add competition for

your food source, the ability to survive might decrease.

• 7. Same amount of food with more competitors means that some individuals will not eat enough and die.

• 8. No, because each food source was a different size/shape meaning that the successful beak was adapted for that particular food source.

Beaks that were Number of beak types Size and shape of beaks

Present at the beginning of the activity

Successful at eating small seeds at island 1, round 1

Failed to eat small seeds at island 1 and MIGRATED

Successful at eating small seeds, round 2

Successful at eating large seeds, round 2

Failed in round 2 (SPECIES EXTINCT)

Successful at competing for small seeds, round 3

Successful at competing for large seeds, round 3

Failed in round 3 (species extinct)

Analysis: Student Lab Packet, Pages 5 & 6

• Answer questions 6-8.• Using your notes, review book or textbook,

record the definitions for question 9.• Use figure 1 on page 6 to answer questions

10-12.

Analysis Question, p.6• 9. Variation = differences among species that

may affect its ability to survive; different beaks (tools)

• Competition = fighting for resources; Round 2 when everyone fought for food off the same plate

• Struggle for Survival = finches fight for food and the ones who are best adapted will survive

• Adaptation = favorable traits that allow an organism to survive; tweezers & chopsticks

Analysis Questions p.9

• Environment = plate of seeds particular to the island the bird lives on

• Selecting Agent = the size of the seeds

Analysis Questions p.710. Large ground finch because it eats mainly

plant food and they have big, thick beaks.11.a. Both animal and plant food. Information

from the chart was used.11.b. No because they don’t eat the same food

(they do not occupy the same niche).11.c. The ground finches will be affected

because they will have to compete with the sharp-billed ground finches for plant food.

Analysis Questions p.7

12. a. Small ground finches would need access to smaller seeds while large ground finches would need access to larger seeds.

12.b. Take 2 different sized tools (one small and one large) and put both small and large seeds on the plate and see which tools were better adapted for each type of seed. (multiple trials)