Sagebrush and Sage Grouse Diets: A lab investigation
Heyyyy… How about
you and I go grab a
bite of A. papposa?
Really… A. papposa?
Sorry, I only eat A.
longiloba.
Guiding Questions:
How can we tell if a species (taxa) of sagebrush is palatable to sage grouse? How do
characteristics like leaf shape and fluorescence help us identify species of sagebrush? What can
this information tell us about the quality of sage grouse habitat?
Equipment and materials
-
Pocket guide to sagebrush:
http://www.sagestep.org/pubs/pubs/sagebrush_pock_guide.pdf
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Photos of bushes that the samples
were collected from
Map of sample locations
Hand-out on UV-light fluorescence,
palatability, and sage grouse
Hand-held magnifying lenses
Microscope
Microscope slide and slip cover
Tape/marker to label samples
-
Ribbon tapes
Glass test tubes
Test tube racks
Water
Pipettes and beaker
Hand-held UV light
Dark boxes or a dark space
Sagebrush samples
Science journal/notebook to record
observations and data
Safety
UV exposure can damage your eyes. Never look directly into a UV light or point a UV light at
another person’s eyes.
Handle glassware carefully. Sometimes glassware breaks. Please report any breakages to the
teacher and do not handle broken glass with bare hands.
Please keep all water away from the microscopes and electrical cords.
Procedure
Pre-lab directions:
1. Read the handout about sagebrush palatability, UV-light fluorescence, and sage grouse
2. Examine the map locations where the sagebrush samples were collected
3. Answer the pre-lab questions in your journal
Pre-lab questions:
1.
2.
3.
4.
5.
What type of habitat do sage grouse prefer?
What do sage grouse primarily eat?
What does palatability mean?
What does fluorescence show us in terms of palatability and sage grouse?
Are there any exceptions to the fluorescence/palatability rule? Do sage grouse like
some sagebrush species that are not fluorescent? Are some fluorescent species not
very palatable? Why should scientists not rely exclusively on the fluorescence test to
determine the palatability of sagebrush?
Lab procedure:
Complete the following tasks for each of the samples at your lab table:
1. In your journal, label the sagebrush sample with its letter/number combination.
LEAF SHAPE AND CHARACTERISTICS:
2. Use the hand-held lens and microscope to examine each sagebrush sample. In your
journal, draw what you see as accurately as possible with the hand lens and on low
power under the microscope. Make sure your drawing goes with the correct label.
3. What is the leaf shape: cuneate (wedge-shaped, triangular, gradually tapering to the
base) or flabelliform (bell shaped)?
4. Measure the length and width of an average-size leaf in centimeters.
UV-LIGHT FLUORESCENCE
5. Clip five leaves from each sample and place them in a test tube. Thoroughly wash your
hands in between samples to avoid cross-contamination.
6. Use a pipette to fill the test tube with 10 mL of water. Cover the open end of the tube
with your thumb.
7. Shake the test tube vigorously for 30 seconds.
8. Use a hand-held UV light to check the test tube for fluorescence in the dark box. Repeat
this process at least twice and compare each sample to the others.
9. Rate each sample along a line as follows:
________________________________________________________________________
No fluorescence
light fluorescence
moderate fluorescence
intense fluorescence
SCENT
10. Each sample of sagebrush will have a unique scent. Smell each of the samples and
describe the scent as best as you can. Do any of the scents remind you of anything?
IDENTIFICATION/DATA ANALYSIS
11. Review the data tables about UV-light fluorescence and palatability. Use these tables
and the pocket guide to sagebrush to identify each species of sagebrush. Pay special
attention to leaf shape and fluorescence. You might consider doing some grouping to
help you narrow down the choices. Could you group by fluorescence, leaf shape,
sagebrush size (big v. low)? Give it a try.
12. Complete the identification and palatability ranking tables on your lab sheet.
13. Clean your test tubes with soapy water and rinse thoroughly.
14. Complete the post-lab tasks.
Post lab tasks:
1. Complete the data tables on your lab handout. Make sure that the tables are accurate
and each sample is labeled and accurately described and identified.
2. What did this lab teach you about palatability and sagebrush? Write a one paragraph
summary using TDPP (topic, details, pattern, point) to communicate what you learned
about palatability and sagebrush identification.
3. With your paragraph, answer the following question: What else might we be able to do
with the fluorescent properties of sagebrush? How could this be used in a different
way?