1. The effect of arthropods on Dipodomys spectabilis food stores and storing behavior By: Amanda Schaupp Mentor: Jose Herrera

2. What is a kangaroo rat? Granivorous rodent Granivorous rodent Desert grassland ecosystem Desert grassland ecosystem Are distributed in Southwestern U.S and Mexico Are distributed in Southwestern U.S and Mexico Ecosystem engineers Ecosystem engineers Evolutionary adapted to use only metabolic water Evolutionary adapted to use only metabolic water Seed diet Seed diet Morphological adaptations Morphological adaptations

3. Kangaroo rats on Sevilleta Dipodomys ordii Dipodomys ordii Dipodomys merriami Dipodomys merriami Dipodomys spectabilis (banner-tail) Dipodomys spectabilis (banner-tail) Biggest in Sevilleta Biggest in Sevilleta White-tipped tail White-tipped tail Dipodomys ordii Dipodomys merriami Dipodomys spectabilis

4. Storing behavior of banner-tail Store seed caches in mounds Store seed caches in mounds Stashed vertically inside wall of mound Stashed vertically inside wall of mound Store seed caches for hibernation Store seed caches for hibernation But how do they do this and why? But how do they do this and why? DenSeed Caches

5. Hypothesis on storing behavior of banner-tail Preliminary hypothesis: banner-tail stick the stalk in their mouth, push it back quickly, bite, and do this continuously Added onto hypothesis later: spit seed caches out and push forward onto inside wall of the mound

6. Methods Trapped using Sherman traps Trapped using Sherman traps Place 3 stalks of Sporobolus cryptandrus (sand dropseed) in terrarium Place 3 stalks of Sporobolus cryptandrus (sand dropseed) in terrarium Conducted video recordings using red light from 4am-7am Conducted video recordings using red light from 4am-7am

7. Video

8. Why place the seeds vertically? Fungal Theory Fungal Theory Fungal growth caused by amount of moisture in den Fungal growth caused by amount of moisture in den Horizontally placed stacks containing seeds would imbibe water Horizontally placed stacks containing seeds would imbibe water Behavioral Hypothesis Behavioral Hypothesis Vertically placed seed caches are more difficult for ants and arthropods to harvest Vertically placed seed caches are more difficult for ants and arthropods to harvest DenSeed Caches

9. What steals the seed caches? Ants are the primary seed stealers Ants are the primary seed stealers Watched them carry away seed stems and leave empty shells Watched them carry away seed stems and leave empty shells

10. Methods of behavioral hypothesis Used kangaroo rat exclusion trap and dug shallow hole in mound Used kangaroo rat exclusion trap and dug shallow hole in mound Seed caches placed in mound vertically, horizontally, and scattered Seed caches placed in mound vertically, horizontally, and scattered Kangaroo Rat Exclusion Trap Vertical Horizontal Scattered

11. Hypothesis on arthropod behavior Assumed that scattered seeds would be taken first, followed by horizontal, and then vertical Assumed that scattered seeds would be taken first, followed by horizontal, and then vertical Reasoning behind this is optimal foraging Reasoning behind this is optimal foraging

13. Results of arthropod behavior Used separate two-way ANOVAs with stalk orientation and den activity as main factors Used separate two-way ANOVAs with stalk orientation and den activity as main factors Effect of orientation F=0.74, df=2, p=.48 Effect of den activity F=2.45, df=2, p=.1263 F=0.09, df=2, p=.9141 F=1.71, df=2, p=.1993 Trial 1 Trial 2

14. Conclusion Kangaroo rats store seed caches vertically in mound Kangaroo rats store seed caches vertically in mound Possible reasons are Possible reasons are Fungal Theory Fungal Theory Behavioral Hypothesis Behavioral Hypothesis Or maybe something else? Or maybe something else?

15. Acknowledgements University of New Mexico University of New Mexico Sevilleta National Wildlife Refuge Sevilleta National Wildlife Refuge Sevilleta LTER Sevilleta LTER National Science Foundation National Science Foundation US Fish and Wildlife Service US Fish and Wildlife Service Jose Herrera and his students Jose Herrera and his students Jennifer Johnson Jennifer Johnson 2009 Sevilleta REUs 2009 Sevilleta REUs 2009 Sevilleta Interns 2009 Sevilleta Interns

16. Questions?