White-tailed deer are an important reservoir for pathogens that can contribute a large portion of microbial pollution in fragmented agricultural and forest landscapes. The scarcity of experimental data on survival of microorganisms in and release from deer feces makes prediction of their fate and transport less reliable and development of efficient strategies for environment protection more difficult. The goal of this study was to estimate parameters for modeling Escherichia coli survival in and release from deer (Odocoileus virginianus) feces. Our objectives were as follows: (i) to measure survival of E. coli in deer pellets at different temperatures, (ii) to measure kinetics of E. coli release from deer pellets at different rainfall intensities, and (iii) to estimate parameters of models describing survival and release of microorganisms from deer feces. Laboratory experiments were conducted to study E. coli survival in deer pellets at three temperatures and to estimate parameters of Chick's exponential model with temperature correction based on the Arrhenius equation. Kinetics of E. coli release from deer pellets were measured at two rainfall intensities and used to derive the parameters of Bradford-Schijven model of bacterial release. The results showed that parameters of the survival and release models obtained for E. coli in this study substantially differed from those obtained by using other source materials, e.g., feces of domestic animals and manures. This emphasizes the necessity of comprehensive studies of survival of naturally occurring populations of microorganisms in and release from wildlife animal feces in order to achieve better predictions of microbial fate and transport in fragmented agricultural and forest landscapes.F ecal bacteria are a leading cause of water body impairment in the United States (1), and Escherichia coli is currently used by the Environmental Protection Agency (EPA) as an indicator organism for fecal contamination and bacterial impairment for watersheds. Currently, there are 3,451 impaired water bodies in the United States, based on E. coli monitoring (1). It has been recognized that livestock and wastewater are major sources of fecal contamination in watersheds (2-4), while cattle are commonly considered a principal reservoir of E. coli O157:H7 (5-7). However, in fragmented agricultural and forest landscapes, wildlife can contribute a large portion of the fecal pollution (8-11), also serving as a reservoir for pathogens. E. coli O157:H7 was found in feral swine in Sweden (12) and in California, USA (13-15); E. coli O157:H7 were also isolated from feces of white-tailed deer cograzing with cattle (16-18). Black-tailed deer were identified as a source of E. coli O157:H7 strawberry-transmitted infection in Oregon, which caused 15 illness cases, including two deaths (19). Seventy people were reported to be infected by E. coli O157:H7 after consumption of unpasteurized apple juice in the western United States and British Columbia, Canada, in October 1996. This outbreak of E. coli...