Aging a deer has always been a difficult task. The most common technique is to look at the development and wear of its teeth. While this practice is widely used and accepted (Severinghaus 1949, cited in Gee et al. 2002), a study on 106 deer jawbone samples reveals that it may not be very accurate. The researchers were unable to assign a specific age to the jawbone samples, but categorized them into 3 basic age classes (fawn, yearling and adult). Thirty-four white-tailed deer biologists then attempted to age the jawbones, and failed 60% of the time for samples greater than two years of age. The results found the method of using tooth wear to indicate age very inaccurate beyond that of the 3 basic age classes (Gee et al. 2002).
Habitat preference and sexual segregation
In 2002, a team of researchers used data from forest maps and field surveys to investigate habitat preference and gender segregation of white-tailed deer. They hypothesized that does would seek out dense, sheltered forest during growing season to protect their fawns. The map analyses did not reveal gender segregation, but the field surveys showed that habitat preferences differed by gender. While both sexes used dense forest in the growing season, the males eventually spread out into more open spaces later in the season. The researchers concluded that aerial maps are not detailed enough to be indicative of habitat preference (Lesage et al. 2002).
Deer density based on aerial surveys and pellet-based distance sampling
In 2008 to 2009, a team of researchers compared aerial surveys and pellet-based distance sampling to estimate deer density in 6 preserved forests near Chicago, Illinois. They compared density estimates obtained from the use of both methods, as well as costs, bias, and precision. It was concluded that collecting accurate data on pellet decay and decomposition rates, using a large enough sample size, would be a more efficient and advantageous way of collecting density data than aerial surveys. Data from pellet samplings were less costly, required less equipment and professional skill, and did not depend on snow covering the ground. To conclude, the team discussed the importance of further research (Urbanek et al. 2012).