Low recruitment is the largest challenge facing the recovery of the critically endangered Mississippi Sandhill Crane (Grus canadensis pulla). Lack of information on sources of nest failure hinders effective management to increase recruitment. I examined sources of nest failure for 54 nests at the Mississippi Sandhill Crane National Wildlife Refuge, 2008-2009. Nest cameras identified predation as the primary source of failure, followed by flooding, abandonment, and egg inviability. Mean daily survival rate (DSR) was 0.72. The best approximating models included covariates for season date, temperature and nest age. DSR decreased with increasing season date, increasing nest age, and decreasing temperature. Hypotheses related to effects of renesting, human disturbance, precipitation, flooding, and winter rain were not supported. Because predation has been identified as a primary source of nest failure, I also monitored mammalian predators on the MSCNWR. Coyotes and raccoons were most common, with gray foxes, red foxes, domestic dogs, and bobcats also detected frequently.