Rodolfo Dirzo with an elephant, one of the species of large herbivore experimentally removed from the study plots in Kenya.
Rodolfo Dirzo with an elephant, one of the species of large herbivore experimentally removed from the study plots in Kenya.

Linkages between wildlife defaunation, savannah ecosystem structure and composition, and consequences for small mammal abundance in the context of risks for human health

This study combines experimental manipulations of wildlife together with “real life” pairwise comparisons (intact vs. defaunated landscapes) in the context of landscape heterogeneity and land use change. As an example of the cascading consequences of defaunation, we found that when large herbivores are experimentally removed, the abundance of rodents increases dramatically, along with the abundance of fleas, which carry Bartonella, a genus of bacteria able to infect both humans and other animals. Ongoing research at this site includes the DNA-based identification of the diverse pathogens vectored by the ectoparasites found on rodents.

Collaborators: Hillary Young, Douglas McCauley (University of California Santa Barbara), Truman Young (University of California Davis)

Funding: Stanford Woods Institute for the Environment, Stanford Biology Department.

Rodolfo and field assistant sampling vegetation at control sites at Mpala Research Station, Kenya.
Rodolfo and field assistant sampling vegetation at control sites at Mpala Research Station, Kenya.
Rodolfo and field assistants sampling vegetation at control sites at Mpala Research Station, Kenya.
Rodolfo and field assistants sampling vegetation at control sites at Mpala Research Station, Kenya.
Rodolfo and two undergraduate assistants combing rodents for fleas, Mpala Research Station, Kenya.
Rodolfo and two undergraduate assistants combing rodents for fleas, Mpala Research Station, Kenya.
Rodolfo Dirzo with an elephant, one of the species of large herbivore experimentally removed from the study plots in Kenya.
Rodolfo Dirzo with an elephant, one of the species of large herbivore experimentally removed from the study plots in Kenya.
Rodolfo conducting a dung survey at a control site, Mpala Research Station, Kenya.
Rodolfo conducting a dung survey at a control site, Mpala Research Station, Kenya.