Mutualism and Co-evolution
A study of Flowering Plants and their Pollinators
with a focus on

Form and Function

Case Study: Double Arrow Nest

One adult female, two adult males shared this nest with two nestlings. Female A spent most of her time near the nest. She incubated the eggs and cared for the two nestlings. Both males contributed to the care for the young. Male B was clearly dominant over Male C. Male B chased Male C away whenever he came within 50 meters of the nest. If Male C settled too close to the nest, Male B would perch on top of him until Male C left. Male C was not allowed to incubate the eggs or directly feed the nestlings.

1) What are the behavioral roles of Female A, Male B, and Male C? Who does this suggest is reproducing?

2) Who are the parents of each of the offspring?

• n1?
• n2?
  

3) Are all of the adults reproducing?

4) Does the genetic data support the behavioral observations? Are only the Alpha birds reproducing?

 

 

Case Study: Pancho Villa Road Nest

One adult female and two adult males shared this nest in the center of town. All of the birds hunted together, catching prey for themselves and the three nestlings. The female spent themost time in the nest carrying for the young, but occasionally allowed Male C to help. Male C perched on a saguaro cactus near the nest and chased Male B away. Male C was seen mating with the female.

Study the DNA profile at the right then answer the following questions in your data chart.

1) What are the behavioral roles of Female A, Male B, and Male C? Who does this suggest is reproducing?

2) Who are the parents of each of the offspring?

• n1?
  
• n2?
  
• n3?
  

3) Are all of the adults reproducing?

4) Does the genetic data support the behavioral observations? Are only the Alpha birds reproducing?

 

Case Study: Ranch Nest 1988

Two adult females share this nest with a single male. Both females participate in the incubating of eggs and caring for the four nestlings. Female A spent more time in nesting behavior while Female B spent more time capturing food and delivering it to the nest. Female A was seen mating with Male C; Female B was not.

Study the DNA profile at the right then answer the following questions in your data chart.

1) What are the behavioral roles of Female A, Female B, and Male C? Who does this suggest is reproducing?

2) Who are the parents of each of the offspring?

• n1?
  
• n2?
  
• n3?
  
• n4?

3) Are all of the adults reproducing?

4) Does the genetic data support the behavioral observations? Are only the Alpha birds reproducing?

 

 

 

Case Study: Ranch Nest 1989

The following year, biologists returned to study the Harris' hawks on the ranch. Two adult females shared this nest with a single male. Again Female A spent more time in nesting behavior while Female B spent more time capturing food and delivering it to the nest. Female A was seen mating with Male C, but Female B was not.

Study the DNA profile at the right then answer the following questions in your data chart.

1) What are the behavioral roles of Female A, Female B, and Male C? Who does this suggest is reproducing?

2) Who are the parents of each of the offspring?

• n1?
  
• n2?
  
• n3?
  

3) Are all of the adults reproducing?

4) Does the genetic data support the behavioral observations? Are only the Alpha birds reproducing?

 

Case Study: Mile Post 246 Nest

One adult female, two adult males, and two nestlings share this nest. Female A incubates and cares for the two nestlings; she spends most of her time near the nest. The males spend different amounts of time near the nest and engaged in the direct care of the young. Male C spends more time feeding and caring for the young. Whenever Male B comes within 50 meters of the nest, Male C quickly chases him away. Male C is seen mating with Female A; Male B is not.

The biologists were only able to capture four of the birds at this nest. Despite repeated attempts, Male C was never captured. The DNA profiles for the Female A, Male B and the two nestlings are shown at the right.

1) What are the behavioral roles of Female A, Male B, and Male C?

2) Who does this suggest is reproducing?

3) Who are the parents of each of the offspring?

• n1?
• n2?
  

4) Are all of the adults reproducing?

5) Does the genetic data support the behavioral observations? Are only the Alpha birds reproducing?

 

Case Study: Double Arrow Nest

One adult female, two adult males shared this nest with two nestlings. Female A spent most of her time near the nest. She incubated the eggs and cared for the two nestlings. Both males contributed to the care for the young. Male B was clearly dominant over Male C. Male B chased Male C away whenever he came within 50 meters of the nest. If Male C settled too close to the nest, Male B would perch on top of him until Male C left. Male C was not allowed to incubate the eggs or directly feed the nestlings.

1) What are the behavioral roles of Female A, Male B, and Male C? Who does this suggest is reproducing?

2) Who are the parents of each of the offspring?

• n1?
• n2?
  

3) Are all of the adults reproducing?

4) Does the genetic data support the behavioral observations? Are only the Alpha birds reproducing?

 

Previous

Student Activity:

DNA Analysis from Cheek Cells

Agarose Gel Preparation

Harri's Hawks: Case Study

Materials List

Resource List

The University of Arizona
Department of Biochemistry and Molecular Biophysics
General Biology Program for Secondary Teachers
warder@email.arizona.edu