After Humboldt, Deven went on to work as a wildlife biologist in southern California.  For his thesis, Deven studied the effects of shade tree species in Kenyan coffee farms on insectivorous bird foraging behavior. Specifically, his research looked at whether Cordia africana (a tree indigenous to central Kenya) or Grevillea robusta (an introduced species from Australia) attracted higher prey abundances for insectivorous birds, and the capacity for different tree species to help deliver pest control services on the farms. Identifying differences in prey abundance and preferences in bird foraging behavior not only fills basic gaps in our understanding of the ecology of East African coffee farms, it also aids in developing region-specific information to optimize functional diversity, ecosystem services, and the conservation of birds in agricultural landscapes.