This post was written by Trey Smith, the Library of Congress 2015-16 Science Teacher in Residence.
Lionfish and tumbleweed and boars! Oh my! Invasive species overtake both ecosystems and news headlines. Historical primary sources, such as newspapers from Chronicling America, paired with modern periodicals, reveal how organisms introduced into new ecological contexts can cause unexpected consequences.
To begin a unit or lesson on complex interactions in ecosystems, ask students to brainstorm what they know about kudzu and then introduce historic newspaper articles about the plant, including:
- a 1912 article about using kudzu as hay,
- a 1913 article describing the U.S. Department of Agriculture’s positive view of the plant, and
- a 1919 article with images of farmers planting and harvesting kudzu.
Students might consider:
- When and why was kudzu introduced in America?
- What do the articles reveal about perspectives on kudzu at the time?
- How have scientific and public perspectives on kudzu changed since then?
As part of their further investigations, students can seek out reliable secondary sources and additional primary sources about invasive species such as kudzu. Students might grapple with issues related to human interactions with the environment, engineering solutions, and the effects of newly introduced species on biodiversity.
Teachers and students can find other articles about kudzu in Chronicling America, which provides access to more than 10 million full-text searchable newspaper pages from 1836 to 1922. Search terms appear in red in the results.
Articles from Chronicling America also describe the emergence of another invasive species, the European starling. Eugene Schieffelin introduced the birds in New York’s Central Park at the end of the 19th century as part of an effort to bring to America every bird mentioned in Shakespeare’s plays. A 1910 article questions whether the starling will become a pest while a 1921 article proclaims the starling a “most useful bird.”
Students can compare these news stories to one another as well as to modern articles. Students might also consider similarities between the introductions of European starlings and Eurasian wild boars.
Primary sources illustrate how invasive species not only overtake ecosystems but also begin to represent geographical locations. Just as kudzu is a ubiquitous image in the American South, tumbleweed is commonly associated with the American West.
- Newspaper articles from 1898 and 1910 describe the introduction and invasive nature of tumbleweeds or Russian thistle.
- Photos from 1936 in Iowa and 1939 in Montana show individuals interacting with tumbleweeds.
- 1934 sheet music from Gene Autry reflects tumbleweed as a symbol of the West.
Students might dig into both primary and secondary sources to explore how invasive species take root in culture and public discourse.
Finally, some invasive species do not appear in historic newspapers in Chronicling America because they had not yet been introduced. Students might look to federal legislation on Congress.gov to find mentions of species more recently recognized as invasive. For example, a search for the zebra mussel renders laws from the past two decades that address this organism specifically.
Invasive species are important starting points for exploring scientific concepts related to ecosystems, biodiversity, stability, and change. Which invasive species are you interested in learning more about?