Dipodomys spectabilis: Ecosystem Engineers

1. Dipodomys spectabilis: Ecosystem Engineers A look at Invertebrate Richness and Abundance By: Scott Johnson Mentor: Andrew Edelman

2. Dipodomys spectabilis • Banner-tailed Kangaroo Rat • Granivorous rodent • Desert Grassland Ecosystem • Ecosystem Engineers

3. Building Microhabitats • Construct Mounds • Earth slightly raised off the Ground • Several entrances scattered across the mound • Usually One K-rat per Mound

4. (Whiteman 2007) Supporting Evidence • Thomas J. Valone, 1997 • Ant Correlation • Hawkins and Nicolleto, 1992 • Mounds effect spatial organization of ground dwelling animals • Shawn Whiteman, 2007 • Reptile Diversity Unoccupied

5. Research Questions • How do mounds built by Dipodomys spectabilis influence invertebrate diversity? • Is overall richness and abundance at both occupied and unoccupied mounds higher than away from the mounds at the random grass sites? • Is overall richness and abundance at occupied mounds higher than unoccupied mounds?

6. Methods • Set up pitfall traps to catch mainly terrestrial invertebrates • 45 sites; 15 occupied mounds, 15 random sites, and 15 unoccupied mounds • Random Sites set up at least 20m away • Two pitfall traps at each site, totaling 90 traps, opposite each other at random directions • Traps opened for five to six day periods • Five total collections on 7-2, 7-9, 7-16, 7-23, 7-30 • Traps open a total of 27 days

7. Nunn Flats

8. Occupied Random Unoccupied

9. Methods, cont. • Two Solo Cups ¼ full with Propylene Glycol • Pitfalls covered with ceramic tile to keep out debris and rain • One meter plot around each trap measured for percent cover of grass, forbes, detritus, and bare ground • Mound diameter measured and holes counted • The invertebrates identified at the UNM arthropod museum by Dr. Brantley

10. Results Invertebrate List Eleodes sp. Elateridae Scolopendra polymorpha Edrotes rotundus Dasymutilla vestita Eremobates sp. Sphecidae Vaejovis coahuilae LycosidaeEleodes longicollisArenivaga erratica MyrmeleontidaeCeuthophilus pallidus Psilochorus imitatus Pasimachus sp. Psoloessa sp. Ophryastes globularis Sphaeropthalma sp. Cicindela punctulata Pompilidae Melanastus sp. TyphoctinaeScutellaridae Amphitornus coloradus Gryllus sp. Tachinidae Emblethis vicarious Cymatodera neomexicana Unknown Fly1CicadellidaeEpicauta sp. ChloropidaeNoctuidaeUnknown MothTachinidaeLygaeidaeChrysopidaeAraeoschizus sp.Trombidium sp. Efferia sp.Dactylotum bicolorReticulitermes tibialis Phyllophaga sp. Xanthippus corallipesCremastocheilus sp.TingidaeOmorgus sp.Litaneutra minorNicrophorus guttulusTrimerotropis pallidipennisMelanoplus sp. Trachyrhinus marmoratusSyrphidaePhrynotettix robustusOrthoporus ornatus Latrodectus hesperusParabacillus coloradus Tropidolophus formosusHelluomorphoides sp. Dasymutilla sp. Unknown Fly 2 All three types Occupied only Occupied and Unoccupied Unoccupied Only Unoccupied and Random Random Only Occupied and Random

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14. a b b c a a b b a a a a grass forbes detritus bare ground

15. Discussion • Statistically, Occupied mounds had significantly more diversity in average richness and average abundance than Unoccupied mounds or Random grass sites. • Occupied and Unoccupied mounds were similar in size, but Occupied mounds had more openings. • The type of vegetation cover over Occupied mounds differed from Unoccupied mounds and the Random Grass Sites.

16. Discussion • How do mounds built by Dipodomys spectabilis influence invertebrate diversity? • Is overall richness and abundance at both occupied and unoccupied mounds higher than away from the mounds at the random grass sites? • No. Richness and Abundance at Occupied mounds are significantly higher. • Unoccupied mound diversity is similar to diversity at the Random site, though the components of the diversity differs. • Unoccupied mound data tends toward an intermediate trend.

17. Discussion • How do mounds built by Dipodomys spectabilis influence invertebrate diversity? • Is overall richness and abundance at occupied mounds higher than unoccupied mounds? • YES.

18. Conclusion: The Why • Dipodomys spectabilis altered their surroundings creating microhabitats for invertebrates. • Microhabitat • Unique nutrient, water, and light levels • Soil disturbances on and near the mounds (Guo 1996) • These microhabitats are important to the biodiversity of invertebrates in both abundance and richness

19. Acknowledgments • University of New Mexico • Sevilleta National Wildlife Refuge • National Science Foundation • US Fish and Wildlife Services • Andrew Edelman • Jennifer Johnson • Dr. Scott Collins • Dr. Sandra Brantley • The UNM Arthropod Museum • Shawn Whiteman • Cathy McQueen • Mike Friggens • John DeWitt • Andrew Rominger • 2007 Sevilleta REUs • 2007 Sevilleta Interns

20. Questions?

21. References Best, Troy L (1988) Mammalian species dipodomys spectabilis. American Society of Mammologist 311:1-10 Guo, Qinfeng (1996) Effects of bannertail kangaroo rat mounds on small-scale plant community structure. Oecologia 106:247-256 Hawkins LK, Nicoletto PF (1992) Kangaroo rat burrows structure the spatial organization of ground-dwelling animals in a semi arid grassland. Arid Environment 20:199–208 Valone, Thomas J (1994) Interactions between rodents and ants in the chihuahuan desert: an update. Ecology 75:252-255 Whiteman, Shawn (2007) [enter thesis] Senior thesis