Directions for teachers:

To engage students before reading the article, have them answer the “Before Reading” questions as a warmup in class or for homework. Then, ask students to read the online Science News article “In a ‘perfect comeback,’ some birds use antibird spikes to build their nests” and have them answer the “During Reading” questions. As an optional extension for deeper analysis around the claims made in the article, have students discuss the “After Reading” questions. A version of the article appears in the September 9 issue of Science News. Another version of the same article written at a lower reading level byScience News Explores is also available, “This bird nest becomes a ‘fortress’ using antibird spikes.” The same classroom questions (without visible answers) are appended to that story.

Directions for students:
Read the online Science News article “In a ‘perfect comeback,’ some birds use antibird spikes to build their nests” and answer the following questions as directed by your teacher. A version of the article appears in the September 9 issue of Science News.

Before Reading
1. Why do you think birds build nests? Come up with two possible benefits of those nests to the birds. If you were a nest-building bird, come up with three specific materials that you might use, then explain what benefit each of these materials would provide. (It doesn’t have to be one of the two mentioned previously.)

Answers will vary. But benefits might be protection, central location for raising young, softness, insulation, or a good aerial viewpoint of the surroundings. Materials might include, twigs, hair and/or fur, odds and ends, plant fibers, leaves, and more. Such materials may be associated with many benefits. For instance, shiny odds and ends might be attributed to decorative purposes. Animal hair might offer insulation.

2. Imagine that two school friends both notice the same pattern, which is that they both seem to perform better on tests when they wear green. From these observations, the pair makes the following claim: On average, students who wear green score higher on tests. Do you feel confident about the accuracy of this claim? Explain your answer. What steps (be specific) could be taken next to test these claims?

A student would probably not feel confident in these claims. That’s because the claim has no evidence to support it. As for the next steps, answers will vary. The student might suggest an experiment to test the claims or point out that more observations should be made regarding the pattern.

During Reading
1. As of this story’s publication, how many spike-decorated nests had been discovered in Europe? Where might you usually find such spikes?

Five spike-decorated nests had been discovered in Europe as of this story’s publication. Normally you would find such spikes along building eaves.

2. In what country was the first spike-decorated nest discovered? Describe how this discovery was made.

The first nest was found in Belgium. A hospital patient saw the weird-looking nest outside his window and notified the biologist Auke-Florian Hiemstra.

3. So far, what two bird species have been observed constructing such nests?

Eurasian magpies (Pica pica) and carrion crows (Corvus corone) are the two bird species found to construct such nests.

4. While two bird species seem to construct spiked nests, Auke-Florian Hiemstra believes these species use the spikes for different purposes. For what purpose might each bird species use these spikes, according to Hiemstra?

Hiemstra believes the crows use the spikes to stabilize their nest’s structure, whereas the magpies use them to ward off other birds.

5. These anti-bird spikes serve as a substitute for what type of natural material, according to the scientists?

Scientists suspect these anti-bird spikes might substitute for thorny vegetation.

6. What does the term “citizen science” mean? How does this story describe one use of citizen science?

Citizen science is scientific research in which the public helps to collect data. This study counts as citizen science because non-scientists helped to observe these unusual nests and reached out to scientists.

7. What are some next steps that Hiemstra would like to take to learn more about this phenomenon?

Hiemstra wants to gather more examples of the nests and study if the spikes are improving the survival of the birds in the nests.

After Reading
1. A hypothesis is a possible explanation for a phenomenon, based on limited evidence. Identify one hypothesis made by scientists in this article.

Answers will vary, but may include the following examples. Scientists hypothesize that magpies use the spikes to deter other birds. Or crows use the spikes to support their nests. Or that birds use spikes as substitutes for thorny vegetation.

2. What evidence do the scientists use to support their hypotheses?

Answers will vary depending on the hypothesis identified, but may include the following evidence. Scientists use new evidence gathered from five bird nests around Europe, as well as previous observations of urban birds and their nests. The five European nests incorporate the anti-bird spines. Magpies build domed roofs over their nests using the spines. And magpies tend to use materials they find to add extra protection, based on previous observations.

3. What could scientists do to increase confidence in the claims made in this article? How could scientists go about that process?

Answers will vary. But scientists could increase confidence in claims made in this article by designing experiments to test their hypotheses. They could also acquire more in-field observations.