Our scientists use a variety of methods to find, measure and map animal communities within the preserves. Learn more »
Aerial surveys— These surveys are conducted during winter when deer are most visible. Trained observers count individual deer from a helicopter flying at low altitude. The helicopter is flown along parallel lines at equal distances until the entire preserve has been counted. Aerial surveys have also been conducted to monitor sandhill cranes.
Cover boards—Snakes, salamanders and other small animals are attracted to the safe, dry shelter provided by broad plywood boards set at long-term monitoring points.
Data management—Computers and other technology help us record, store and analyze the information, along with historic records and other accounts. Field equipment including tablet computers and GPS units streamline the process of gathering measurements.
Mist netting—Individual identification of birds and bats allows us to study behavioral trends such as migration, reproductive success and population growth. Fine, loose nets are strung between poles at long-term monitoring. All captures are promptly removed, measured and released to reduce stress.
Motion detection cameras—Elusive night creatures are “captured” using cameras mounted near scent stations built to attract mesocarnivores such as coyotes, foxes and skunks. Night vision photos provide population information.
Fish populations—Seine nets, traps or shocking equipment is used to monitor fish populations. The fish are returned, unharmed, to the same body of water after identification.
Pellet counts—This technique, used to estimate deer density, requires four pieces of data: number of fecal pellet groups deposited daily per deer, period of time pellets are deposited, number of pellet groups in monitoring plots and the area sampled.
Small mammal trapping—Small mammals are surveyed using a grid of live-capture traps set at long-term monitoring points. The traps are baited and checked daily. Once measured, the mammals are tagged and promptly released to reduce stress. Species such as meadow voles and white-footed mice are commonly recorded.
Vocal breeding surveys—We tally noisy creatures such as birds or frogs by ear during their breeding seasons.