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.

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Documenting life history characteristics of populations, especially of herbivorous insects such as butterflies, is fundamental to the ecological study of tropical rainforests. However, we know relatively little about tropical forest butterflies. Here, I combine information gathered using the mark-release-recapture (MRR) approach with manipulative and observational experiments in a natural environment to explore aspects of the population biology of three closely-related species of Costa Rican fruit-feeding understory butterflies (Cithaerias pireta, Dulcedo polita, and Pierella helvina), specifically: vertical stratification, attraction to and persistence in fruit-baited traps, relative abundance and distribution, movement patterns, probabilities of recapture and daily survival, and factors that affect those probabilities. Among the three focal species there were differences in capturability, recapturability, spatial distribution, and degree of vertical stratification. Males appear to fly within smaller home ranges than females, and P. helvina can traverse the entire forest reserve in a single day. These findings have implications for the genetic diversity of these populations and for the risk of local extinction in the face of changing ecological conditions.