Postfire Community Structure of Birds and Rodents in Southern California Chaparral1

Associate Professor of Biology, Pomona College, Claremont, California, 91711. Abstract: Changes in rodent and avian community structure were documented for 42 months following a major fire in southern California chaparral. Rodent species richness, biomass per ha, and diversity reached levels equal to, or exceeding, those in 16 to 20 year old chaparral within 15 to 24 months post-fire. Heteromyids and meadow mice contributed significantly to biomass per ha in early post-fire seres; wood rats and Peromyscus species contributed significantly in older stands. Productivity and diversity of rodents were higher in post-fire seral stages than in older stands. Avian species richness and diversity increased in early post-fire seral stages, probably reflecting an increase in availability of both insect and plant food resources. No significant shifts in feeding guild utilization were noted. A few rodent species may take several years to recolonize burned areas, but avian repopulation is rapid, limited chiefly by the availability of suitable nesting sites.