Name: ________________ Aim 46: NYS Beaks of Finches Lab Date: _______________

1. Identify one adaptation, other than beak size and shape, a finch species might possess and state how that would aid in itssurvival.

Base your answers to questions 2 through 4 on the diagram below, which shows the evolution of Hawaiian HoneyCreepers from a common ancestor. As their ancestors spread to new islands, they found a variety of different food sources.Gradually, behaviors and beak structures evolved that took advantage of these different food sources, resulting in theformation of several new species.

2. Some of the birds that could not compete with the honey creepers were successful living on other islands. State one reasonwhy this could be possible.

3. Other types of birds arrived at the islands, but they found it difficult to compete with the many forms of honey creepers.Explain why the honey creepers were able to compete so successfully against the new arrivals.

4. Describe how the beaks of the bird species D, E, F, and J that eat fruits and seeds differ from the beaks of the bird speciesthat eat only nectar.

1) similar climates on the different islands2) competition between the finches for food3) cloning experiments carried out by native people on the islands4) increased rate of asexual reproduction

5. Which factor most likely contributed to the evolution of Galapagos Islands finches with different beak shapes?

1) members of the ancestral finch species had to decide if they would be better off feeding on seeds rather than onrelatively scarce insect species

2) some of the finch ancestors were born with beaks that were different from the beaks of other finches, and could eat bothinsects and seeds

3) some members of the ancestral species that fed on insects began to die off, leaving few offspring4) another species of bird, a seed eater, arrived on the islands and began to breed with members of the ancestral species

6. The first species of finch to inhabit the Galapagos Islands thousands of years ago was most likely an insect eater. Today,finch species on these islands feed on a great variety of plants and animals. One early event that probably occurred that ledto this feeding diversity was that

Base your answers to questions 7 and 8 on the information below and on your knowledge of biology.

There are two different species of finch that live on the same small island, species A and species B. Both speciessuccessfully feed and reproduce on the island. Species A nests in pine trees and eats large seeds. Species B nests inhollowed-out dead logs and eats small insects.

7. A third species of finch, species C, migrates to the island. It nests in pine trees and eats small insects. Predict what mostlikely will happen to the populations of both species A and species B if species C successfully survives on the island.Support your answer.

1) use different resources and, therefore, they do not compete2) mate with each other, keeping both populations constant3) compete for food, but do not compete for shelter4) eat the same food, but feed at different times of the day

8. Both bird species A and species B can most likely survive on the same small island because they

9. Base your answer to the following question on the information below and on your knowledge of biology.

1) gene expression and asexual reproduction 2) variation and natural selection3) migration and the need to adapt 4) heredity and a diet of seeds

The differences seen in the beaks of the four species of finches are most likely the result of

1) DNA will change to produce structures needed by birds to survive intense competition2) a bird's beak changes annually in response to the type of food that is most abundant each year3) natural selection occurs when there are scarce resources and intense competition4) the beak of a finch will change if the environment of the bird remains stable

10. Studies of the finches of the Galapagos Islands have shown that

Base your answers to questions 11 through 13 on the diagrams below and on your knowledge of biology. The diagramsrepresent the variations in the beaks of finches in the Galapagos Islands and the relative abundance of food sources on acertain island.

11.A bird count was done on the island and the small tree finch was found in all regions. State one possible reason why thesmall tree finch is able to inhabit the entire island.

12.Explain why researchers would most likely observe the large ground finch in regions A and D on the island and not inregions B and C.

1) 2)

3) 4)

13. Which histogram displays the relative abundance of small seeds in regions A, B, C, and D?

Base your answers to questions 14 and 15 on the information below and on your knowledge of biology.

The chart describes the beaks of various types of birds that live in a small island ecosystem containing floweringland plants, aquatic plants, many small mammals, amphibians, and several species of trees.

14. Identify one kind of bird that would show an immediate decrease in number if the flowering land plants were destroyed byan environmental change. Support your answer.

15. Identify the beak type that would be characteristic of predators of small mammals.

Base your answers to questions 16 and 17 on the diagram below and on your knowledge of biology.

1) probing, only 2) probing or grasping3) crushing or probing 4) parrotlike feeding or grasping

16. Several of the Galapagos Islands are inhabited by grasshoppers, beetles, flies, bees, and butterflies. Finches that feed onthese consumers would have beaks adapted for

1) large ground finch and warbler finch2) vegetarian tree finch and medium ground finch3) large insectivorous tree finch and woodpecker finch4) small insectivorous tree finch and cactus ground finch

17. Which two finches could temporarily occupy the same niche?

18. Base your answer to the following question on Evolutionary changes have been observed in beak size in a population ofmedium ground finches in the Galapagos Islands. Given a choice of small and large seeds, the medium ground finch eatsmostly small seeds, which are easier to crush. However, during dry years, all seeds are in short supply. Small seeds arequickly consumed, so the birds are left with a diet of large seeds. Studies have shown that this change in diet may berelated to an increase in the average size of the beak of the medium ground finch.

1) trait is inherited and birds with larger beaks have greater reproductive success2) birds acquired larger beaks due to the added exercise of feeding on large seeds3) birds interbred with a larger-beaked species and passed on the trait4) lack of small seeds caused a mutation which resulted in a larger beak

The most likely explanation for the increase in average beak size of the medium ground finch is that the

19. Base your answer to the following question on the information below and on your knowledge of biology.

In birds, the ability to crush and eat seeds is related to the size, shape, and thickness of the beak. Birds with larger,thicker beaks are better adapted to crush and open seeds that are larger. One species of bird found in the GalapagosIslands is the medium ground finch. It is easier for most of the medium ground finches to pick up and crack opensmaller seeds rather than larger seeds. When food is scarce, some of the birds have been observed eating larger seeds.

Explain this long-term change in beak characteristics using the concepts of:

• competition• survival of the fittest• inheritance

Base your answers to questions 20 through 22 on the information and diagram below and on your knowledge of biology.

Two species of finches found on a particular Galapagos island eat the seeds of a certain variety of plant. Therelative strength of their beaks is shown in the graph below.

20. One of the finch species has a slightly smaller, weaker beak. Is this species 1 or species 2? Support your answer withinformation from the graph.

21. If the environment on the island changed and the seeds of more of the plants became harder to crack open, describe whatthe graph might look like after many years have passed.

22. Select the point on the graph where beak strength of the two bird species is equal. Support your answer.

1) different species of finches adapting to different environments over many generations2) finches changing their beak characteristics so that they could feed efficiently3) finch species with different beak structures coming to the Galapagos Islands from the mainland4) finches mating with birds of other species and acquiring some of their traits

23. The diagram below represents the relationship between beak structure and food in several species of finches found on theGalapagos Islands.

The different beak structures observed in the diagram are evidence of

24. State two reasons why the large ground finch and sharp-billed ground finch could live on the same island but not competefor food, even though they both eat mainly plant food.

1) The type of beak indicates the type of food the finch eats.2) Different birds have different songs.3) Birds with larger beaks can find mates more easily.4) Nesting behavior of finches is an inherited trait.

25. Which statement is a basic assumption from The Beaks of Finches lab?

26. There are a number of islands in the Galapagos that these finches could possibly inhabit. Explain why each island would not be expected to have all of the species shown.

27. Identify one species of finch that would most likely survive a sudden change in climate that destroyed seeds with small,thin coverings, leaving only seeds with large, thick coverings. Support your answer.

Answer KeyBEAKS LAB PRACTICE

1. Adaptation: fast flightspeed— to escapepredatorsAdaptation:camouflage— to hide frompredatorsAdaptation: eyesight— to locate foodAdaptation: matingbehavior (songs)— to attract mates

2. – There were nothoney creepers tocompete with. –There was enoughfood for them on theother island. – Theywere well adapted tothe conditions on theother island.

3. – The honey creeperswere well adapted tothe conditions on theislands. – They hadevolved specificskills/structures tofind food on Hawaii.– They were betteradapted than the newarrivals.

4. – Fruit and seedeaters have shorter,thicker beaks. – Thenectar-eating birdshave longer, thinnerbeaks. – Their beaksare shorter.

5. 2

6. 2

7. – Both species A andspecies B willdecrease in number,since species C competes with eachof them. – Species A will compete withspecies C for nestingsites and species B will compete forfood. Therefore, thepopulations of both A and B will decrease.– Both will survive ifthey are adequateresources.

8. 1

9. 2

10. 3

11. –The small tree fincheats mainly animalfood (insects), andinsects are found inall four regions onthe island. –Insectsare found in allregions.

12. –Large groundfinches prefer largeseeds. –Region B andC lack the preferredfood source of largeground finches,which is large seeds.–Large groundfinches have largeedge-crushing bills,which are best foreating the large seedsfound only in regions A and D.

13. 1

14. —humming-birds–no flowersavailable to obtainnectar from —sparrows–no seedsavailable for food —birds with crackerbeaks–no seedsavailable for food

15. — shredder — sharp,curved beak

16. 2

17. 3

18. 1

19. • Competition forfood would increaseas small seedsbecame scarce. Birdswith larger, thickerbeaks would have abetter chance ofsurviving when theseeds were larger andtougher to crack.Birds with normalthickness beakswould be less likelyto survive.Reproduction of thesurviving birds, manywith the larger,thicker beaks, wouldproduce moreoffspring inheritingthe better adaptedbeak type. Over time,this would lead to alarge proportion ofthe population havingthe thicker beaks.

20. — They have theweaker beak becausethe majority of thepopulation is at thelow end of the graph.— because it has aweaker beak thanspecies 2, — exceptwhere the two linesoverlap, More ofspecies 1 finches areat the low-strengthend of the graph.

21. — The curve forspecies 1 may belower and shorter. —The curve for species1 may be eliminated.— Both curves mightshow an increase inbeak strength. —There would be moreindividuals in species2 than in species 1.— The curve forspecies 1 would shiftto the right. answertext here.

22. []— At point C, thebeak strength has thesame value for bothspecies. — becausethat is where the linesintersectwer text here.

23. 1

24. They have differentbeak structures. —They might eatdifferent types ofplants. — They mighteat at different timesof day or night. —They might live indifferent areas of theisland.

25. 1

Answer KeyBEAKS LAB PRACTICE

26. Each island has itsown set ofenvironmentalconditions whichmight not providefood or shelter forsome of thesespecies. — Differentislands might havedifferent kinds offood available. — toomuch competition

27. []— large ground finchor medium groundfinch or small groundfinch or sharp-billedground finch becauseit has a large crushingbeak and eats mainlyplant food —large/small tree finch or woodpecker finch or warbler finchbecause they don't eatmuch plant food —The warbler fincheats only animalfood, so it would notbe affected.