Dramatic reduction in predation on marine turtle nests through improved predator monitoring and management

We describe improvements to monitoring/indexing methodology for predators of marine turtle nests on the east coast of Florida, and the resulting marine turtle conservation implications from integrating the methodology into predator management. A strip transect from dune line to the shore improved an already successful design for monitoring raccoons, and was also sensitive for armadillos. The data were integrated into predator management operations to effectively and efficiently remove the species responsible for turtle nest predation. Tracking plot data also served to validate predator patterns of behavior relative to turtle nesting and improve prospects for preventive predator management strategies. Perhaps the most important finding is that predation at a beach historically suffering nearly complete losses (95%) of marine turtle nests had nest predation reduced to nominal levels (9.4%). For 2002 this predation level represents an estimated 69,000 additional hatchling turtles produced over historical predation rates, and 16,700 additional hatchlings over the previous lowest predation rate.

Monitoring coyote population changes with a passive activity index

A passive tracking index method that has been successfully applied to dingoes (Canis lupus dingo) in Australia was shown to have more general applicability to wild canids by monitoring coyote (Canis latrans) populations in southern Texas. The index was calculated simultaneously for multiple species of animals from observations on the number of intrusions onto a series of tracking plots over several days. We found that the index reflected changes in coyote activity before and after a trapping program on each of 2 ranches. We also were able to simultaneously monitor bobcat (Felis rufus) and white-tailed deer (Odocoileus virginianus) populations, producing some interesting (and unexpected) insights. In our study area, we found it difficult to distinguish the number of rabbit and rodent intrusions into the plots, but these animals might be indexed in other habitats. Analyses of the data as binary responses (presence or absence of spoor on each tracking plot), as has been done in scent-post surveys, reduced the sensitivity and accuracy of inferences.