Whooping Crane Data Labwhooping crane

google doc

The whooping crane (Grus americana), the tallest North American bird, is an endangered crane species named for its whooping sound . It is a tall, white bird with markings on its forehead and face. While in flight, their long necks are kept straight and their long dark legs trail behind. Adult whooping cranes' black wing tips are visible during flight. The species can stand over 1.5 meters (5 feet), males weigh about 7.0 kg (17 lb), while females weigh about 6.0 kg (14 lb).

The  taiga in Wood Buffalo National Park, Alberta, Canada, was the last remnant of the former nesting habitat of the Whooping Crane. They nest on the ground, usually on a raised area in a marsh. The female lays 1 or 2 eggs, usually in late-April to mid-May. Both parents brood the young, but usually no more than one young bird survives in a season. Breeding populations migrate to the Arkansas National Wildlife Refuge and spend their winters there.

The whooping crane is endangered mainly as a result of habitat loss, although cranes are also still illegally shot despite this being subject to substantial financial penalties and possible prison time. At one time, the range for these birds extended throughout midwestern North America. In 1941, the wild population consisted of 21 birds. Conservation efforts have led to a population increase.

One program, Whooping Crane Eastern Partnership , has an interesting way of rearing crane chicks. Eggs laid by captive birds are hatched in incubators and chicks are then raised by project personnel under strict protocols designed to prevent the chicks from imprinting on humans.  To ensure the birds remain wild, handlers adhere to a no-talking rule and wear costumes designed to mask the human form while in the birds' presence.

Pre-Lab Questions:

1. Where are the nesting grounds of the wild population of cranes? __________________________ (place a star next to this sentence)

2. What is the cause of whooping crane endangerment? ____________________________________ (underline this sentence)

3. How many eggs does a female normally lay? ______________

How many chicks usually survive? ____________ (place an x at this section)

4. How many birds were known to be in the wild in 1941? _______________ (place an arrow at this section)

There are several words in the article that are underlined. These words you may not know, but can probably guess the meaning from the context of the article. For each word, suggest a meaning or interpretation.

5. Remnant ____________________________________________________________________
6. Migrate _____________________________________________________________________
7. Substantial __________________________________________________________________
8. Rearing ____________________________________________________________________
9. Personnel ___________________________________________________________________
10. Protocols __________________________________________________________________

Question: What factors increase hatching success of the whooping crane?

Procedure: Review the data on the table and create graphs to compare specific environmental factors.

Data: Chart shows data collected on nesting birds over a 10 year period. Some columns are left blank because you will be adding data.

Year Number of Adults Number of Nests Eggs Laid Eggs Hatched Rainfall (cm) Hatching Success Rate
1 20 6 6 4 9.1  
2 20 3 2 0 15.2  
3 20 4 4 3 11.5  
4 22 5 5 4 6.0  
5 24 4 6 2 6.3  
6 26 8 4 4 8.4  
7 30 6 6 5 7.2  
8 32 0 0 0 19.6  
9 32 4 6 2 14.8  
10 36 10 10 8 8.8  

Step 1: Scan the Data

Look over the numbers on the table and note any trends or features. At this point you are just trying to determine what things the table is telling you.

1. Which three years had the most rain? ________________ Which years had the least rain? _____________
2. Which three years had the most hatched eggs? ______________ Which years had the least? _____________
3. Generally speaking, the number of adults in this population increased or decreased over the 10 years? _______

Step 2: Analyze the Data.

In this step, you will determine the hatching success for each year. Hatching success is calculated with an equation:

For each year, calculate the success rate and add it to the table. This will help you determine which years were more successful for the birds.

Based on the calculations, what were the top 3 years for hatching success rate? _________________
What was the rainfall during those three years? __________________

Step 3: Comparing Data Trends

When comparing data, a graph can help establish trends. While you can glance at the data and see that rainfall may have something to do with hatching success rate, a graph will give you a visual representation of the two factors.


Step 4: Drawing Conclusions

1. Based on the graph, suggest a relationship between rainfall and hatching success. Use a complete sentence.


2. Based on what you know about cranes (you may need to reread the opening article), suggest a reason why rainfall might impact hatching. Use complete sentences.



Step 5: Digging Deeper

1. The data you analyzed only looks at rainfall and hatching success. There are other environmental factors that are not measured here. What are some other things in the environment that could affect the hatching success (list at least 3)


2. The data also does not measure the survival rate of the chicks that did hatch. Suggest a way a researcher could determine the survival rate of the hatching chicks.


3. Another biologist in the area is studying pollution. He records pollution levels in the marsh and suggests that rainfall causes fertilizers to wash into the water. These fertilizers then affect the crane's eggs. At each year, the biologist measures the amount of nitrogen in the water, the measurement is shown in ppm (parts per million). His data is compiled below. Rewrite your hatching success for each year so that you can easily compare values

Year 1 2 3 4 5 6 7 8 9 10
Nitrogen .2 .4 .4 .6 .4 .5 .5 .3 .2 .4
Hatching Success                    

Based on your data, is the researcher correct? Defend your answer using complete sentences.

Related Resources

Case Study – Loggerhead Turtles and Population Models – explore the number of eggs hatched and survivorship

Use Netlogo App to Estimate Population Size – simulation showing how tadpole populations change in different sized ponds, using mark and recapture technique

Ecology Case Study – The Wolves of Isle Royale – population decline and reintroduction of wolves