Multiple mechanisms have been suggested to facilitate coexistence among species of burying beetles, including differential use of habitat and food resources. Nicrophorus marginatus and Nicrophorus guttula are similarly sized burying beetles that co-occur in many parts of their range. We used observations to quantify and compare their diel activity patterns and tested for possible niche partitioning between the species. We monitored activity of individuals of each species over four 24-h periods. Both species exhibit bimodal activity patterns with peaks of activity in the morning and evening. Nicrophorus guttula is active earlier in the morning and later in the evening than N. marginatus. This difference suggests possible temporal niche partitioning and may represent an important mechanism for the coexistence of these burying beetle species.