Learn how the structure of hummingbird tongues are specialized for their function of drinking nectar in this video from NATURE: Super Hummingbirds. In the accompanying classroom activity, students analyze video data on hummingbird feeding.
Pre-Screening Activity: Observing Hummingbirds in the Wild
The Observing Hummingbirds in the Wild handout is designed to be completed before watching Hummingbird Tongue Structure and Function. Introduce the activity by asking students to imagine that they are hummingbirds - how would they try to drink nectar from deep inside a tube without using their hands or tipping the tube over to make the nectar pour down. Hummingbirds can only access flowers while in flight. The flowers they drink from don’t have stems or twigs near them where the hummingbirds can perch. And the amount of nectar in the flowers is so tiny that even if the hummingbirds could knock over the flowers, the nectar wouldn’t drip out. Students may know that butterflies’ mouths are shaped like straws, encourage them to think why hummingbirds do not use their tongues as straws.
During the activity the students will watch three videos of raw footage of hummingbirds feeding. Video 1 introduces students to hummingbird feeding. Videos 2 & 3 are longer, they capture several feedings and some downtime. Students will analyze the hummingbird feeding pattern and the structure of the hummingbird tongue while feeding. The handout can be used with students watching the videos individually or as a class. If students have difficulty grasping the implications of the high-speed videos show them this video of hummingbirds feeding in real time. If students have difficulty generating their own questions about the hummingbird feeding, prompt them to think about the pattern of feeding. Did the hummingbird feed continuously, or several times? If so, was there a pattern in the length of the feedings or the breaks in between? If the students have difficulties finding the times when hummingbirds feed, it’s at 5:36 in video 2 (a second hummingbird arrives while the first is still there at 7:00). And in video 2, the syringe is full of nectar so it’s at gradation zero. The red band that mimics a flower obscures the top of a syringe. In video 3 hummingbirds appear at 13:34 (a second hummingbird arrives while the first is still there at 14:20), 17:30, and 22:25. The last hummingbird doesn’t feed; it only flies around the flower. Discuss why that is a still an important observation with the students. Students can consider that the syringe is almost empty. Or, they can hypothesize that hummingbirds look for something specific in the flowers they feed from and not all hummingbirds may choose to drink from the same flowers.
During share back, discuss how the sample size is too small for meaningful statistical analysis, but how that should inform students’ future experimental design in question 4. Students should have observed the hummingbirds’ tongues split as they drank nectar. After sharing their hypotheses about the function of the split tongue, watch the Hummingbird Tongue Structure and Function video. Then compare students’ hypotheses with Dr. Rico-Guevara’s conclusions. Raw footage was generously provided by Dr. Rico-Guevara. The regular speed video is part of his “Little Hungry Warriors: Examining trade-offs between fighting and feeding in hummingbirds” project. More information about Dr. Rico-Guevara‘s research can be found here.
This activity can be expanded by having students film hummingbirds themselves. Even with cell phone cameras students can capture data, like the volume of nectar in syringes before and after the birds feed, or the length of time each visit lasts.
Data – facts (measurements or statistics) used for reasoning, discussion, or calculation.
Function – natural purpose of an organ or part of a living being.
Nectar – sugar-rich liquid produced by flowers to attract pollinating animals, like hummingbirds.
Structure – the arrangement of parts to form a whole. The structures of living organisms are specialized for particular functions.