Hummingbird populations – How GLOBE students can help

GLOBE’s Earth as a System investigation area cultivates students’ awareness of an intricate web of global connections. Similar to real world scientists, students explore life science concepts, learning that “organisms can only survive where their needs are met.”  The Earth as a System investigation area encourages students to observe patterns and connections, such as through phenology. Phenology is the study of how living organisms respond to seasonal changes in their environment. Only through observing and measuring can we notice if changes are occurring and how they occur.

For example, GLOBE Scientist Sarah Tessendorf recently wrote about her experiences of observing seasonal changes near the GLOBE Program Office. To contribute to GLOBE’s growing database as well as model the learning that GLOBE classrooms conduct each week, the Science and Education team completed the Green-Down Protocol on a tree near our office building.   You can read about these experiences in a blog posted earlier this year.

Seasonal changes mean different things for humans than they do for flora and fauna. While humans in Boulder, Colorado, can wear different clothes or eat different foods to adapt to seasonal variations, the effects of these changes weigh heavier on other living organisms, such as hummingbirds.

One of our other phenology protocols is the Ruby-throated Hummingbird Protocol.  In this protocol, students observe the arrival and departure of hummingbirds, monitor their visits to flowers and feeders, and observe nesting behavior.  This is the exact type of research that National Science Foundation scientists recently wrote about for the journal Ecology. Scientists from the Maryland, Colorado, and Arizona are investigating how the flowering time of the glacier lily, a favorite of hummingbirds and bees, could potentially impact hummingbird populations.  The scientists have found that the glacier lily is blooming 17 days earlier than it did in the 1970s.  In earlier decades, hummingbird migration coincided with the flowering dates.  However, in recent years, hummingbirds have been arriving towards the end of, or even after, the bloom dates.

Glacier Lily
Glacier Lily Photo Credit: David Inouye

Broad-tailed hummingbirds, the type of bird in this study, fly from Central America to the mountains in the western United States to breed and raise their young.  The broad-tailed hummingbirds depend on glacier lily nectar for food.  So, what happens when the hummingbirds arrive and there are no more flowering plants?  These scientists speculate that it could be detrimental for the broad-tailed hummingbird populations.

Broad-Tailed Hummingbird
Broad-Tailed Hummingbird Photo Credit: David Inouye

This goes back to the principle that organisms can only survive when their needs are met – understanding the dynamic interrelations between seasonal changes, limited food, and survival of populations are important lessons.  GLOBE students make valuable contributions to our understanding of hummingbirds – GLOBE student-collected data is a valuable contribution to scientists and global understanding of these birds.

Has your school done the Ruby-throated Hummingbird Protocol?  Or have you investigated another type of animal that migrates into your community?  Let us know what you have found by either commenting or sending an email to

-Julie Malmberg

More Blog Entries