2017 ESA Annual Meeting (August 6 -- 11)

OOS 25-9 - Surprising positive interactions between cattle and wildlife in an African savanna

Wednesday, August 9, 2017: 10:50 AM
D136, Oregon Convention Center
Corinna Riginos, Zoology & Physiology, University of Wyoming, Laramie, WY, Kari E. Veblen, Dept. of Wildland Resources & Ecology Center, Utah State University, Logan, UT, Wilfred Odadi, Department of Natural Resources, Egerton University, Kenya, Duncan M. Kimuyu, Natural Resource Management and Environmental Studies, Karatina University, Karatina, Kenya, Lauren M. Porensky, Rangeland Resources and Systems Research Unit, USDA-ARS, Fort Collins, CO, Grace K. Charles, Department of Plant Sciences, University of California, Davis and Truman Young, Department of Plant Sciences, University of California, Davis, Davis, CA
Background/Question/Methods

Grasslands and savannas often support both wild and domestic large herbivores, and it is widely assumed that these two guilds compete with each other for shared forage resources. Further, it is widely assumed that domestic livestock have substantially different (more negative) effects on community structure and stability than native wildlife. Yet, very few experimental studies have explicitly tested these assumptions nor contextualized them within the broader suite of direct and indirect interactions between these guilds. The Kenya Long-term Exclosure Experiment (KLEE) has, since 1995, allowed us to directly compare the community dynamics in plots accessible to cattle and wildlife (divided into meso- and mega-herbivores), separately and in combination with each other. Since the experiment’s inception, we have investigated the effects of wildlife on cattle foraging behavior and performance (weight gain); the effects of cattle on wildlife habitat use; and compared the effects of cattle and wildlife in maintaining high-productivity hotspots (“glades”), in affecting background forage production, and in driving long-term community change versus stability.

Results/Conclusions

The interactions between wildlife and cattle — and their respective effects on community dynamics — were surprisingly positive in many (but not all) cases. Although wildlife and cattle suppressed each other’s habitat use and weight gain respectively during dry seasons, during wet seasons wildlife facilitated cattle weight gain and cattle appear to have facilitated some wildlife species. Cattle and wildlife also played complementary roles with respect to hotspots of high grass production that benefit both guilds. While these hotspots are created by cattle management, wildlife play a greater role in maintaining them. These positive direct and indirect interactions between cattle and wildlife are contrary to the assumed paradigm of negative interactions between these guilds. Also contrary to expectations, we have found that cattle and wildlife have largely similar effects on herbaceous productivity, composition, and richness. Because cattle are now the most abundant herbivore in this ecosystem, they actually enhance herbaceous productivity and species richness and stabilize long-term community composition more than wildlife. These surprising findings underscore that livestock management at moderate stocking rates is compatible with wild ungulate conservation.