Two very different environments.  Two very different birds.  Both are called 'juncos'. 
What is going on?

About This Video

Grade level: 6-12
Length: 2 minutes
Next Generation Science Standards: HS-LS4.B, HS-LS4.C

Video Synopsis
What once was a single population of juncos who spent breeding season in the mountains and wintered in San Diego has diverged. In the 1980s, people started noticing that there were juncos hanging out in San Diego in the summer.  Today, there is a significant population of year-round juncos in San Diego who are quite different visually and behaviorally from their mountain counterparts.  Have these juncos evolved into a different species in such a short amount of time?  What is going on?


This video was made in collaboration with Chicago Public Schools as part of their NGSS-aligned high school biology curriculum.


Phenomenon-Based Learning

Students working on a robot

As many states are transitioning to the Next Generation Science Standards or something like them, more and more teachers are using phenomenon-based learning to shift from a content-driven classroom to a process-driven one. In the NSTA blog article, read why anchoring phenomena can be useful for helping students advance their own path to science understanding.

Photo courtesy of Allison Shelley/The Verbatim Agency for American Education: Images of Teachers and Students in Action


Cornell Lab of Ornithology: All About Birds

Dark-eyed junco

Want to learn more about juncos?  The Cornell Lab of Ornithology All About Birds database has information about junco behavior, color patterns, habitats, life history, and more.  Learn how to identify juncos by the way they look or how they sound and where you might find them in the wild. 

Photo credit: devra


Next Generation Science Storylines: Natural Selection and Evolution

Next Gen Science Standards Storylines

The phenomenon of the evolution of city juncos is part of a high school biology unit exploring the broader topic of biological evolution available from the Next Generation Science Storylines project.  In this unit, students will delve in to how populations change over time by looking at antibiotic-resistant bacteria in addition to juncos.  Next Gen Sci Storyline units are freely available to teachers and include a full teacher's guide, student activity sheets, material lists, and other resources.


Connections to the Next Generation Science Standards

While this video doesn't necessarily cover the following standards in depth, it is a compelling resource you can use to supplement your curriculum that does.

Disciplinary Core Ideas

  • HS-LS4.B Natural Selection: Natural selection leads to the predominance of certain traits in a population, and the suppression of others.
  • HS-LS4.C Adaptation: Adaptation by natural selection acting over generations is one important process by which species change over time in response to changes in environmental conditions. Traits that support successful survival and reproduction in the new environment become more common; those that do not become less common. Thus, the distribution of traits in a population changes.