Predator Guard Effectiveness

This research project is intended to help document the effectiveness of various guard alternatives and generally raise the awareness of what works, what doesn’t and why. Data collection began in 2006 but more samples and documented situations are needed.

Much has been written about the need for guards and program sponsors have strong feelings about which ones work and whether they even need them. There is no doubt that in some habitat areas, especially in the early years of a project, that predation and harmful nest competition is simply not a factor. No snakes, no coons, no pecking birds or starlings. It is also known (and demonstrated by MWDI) that some project areas have had recurring predator issues and that program sponsors have been oblivious to this fact. (An interim box inspection in mid-May after the snakes get on the move can be most instructive!)

A minimum 7% of all public land boxes that were used had snake or raccoon predation causing the demise of an estimated 250+ eggs. While this is not a large number, it is easy to rectify. More importantly, guards have saved many, many more nests. A predator-free program is likely to be an anomaly over the long term.

MWDI wishes to encourage all projects to maintain adequate predator protection (primarily against snakes and raccoons), at least as a contingency if predation risk is not readily known from periodic and timely nest inspections. To facilitate this, MWDI has developed a reliable supplier of cone-shaped predator guards.