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Delaware Deer Population Management:
2009 Deer Densities and Population Estimates

Survey Background
The State of Delaware completed its first aerial infrared deer population survey in December 2005. This gave residents their first comprehensive deer population estimate for the state. Since the 2005 season, various programs have been put into place to help increase the deer harvest, specifically the harvest of female deer. In 2009, a second survey was completed to determine how the deer population has responded to these changes. Comparing the survey techniques between the 2005 and 2009 surveys, the State made some improvements. Some of those changes were:
1) New survey blocks were flown within each management zone based on the new 2007 aerial habitat photos
2) Location of blocks were randomly selected by a computer program to eliminate survey bias and to more accurately represents habitats within the management zone
3) The survey was conducted in March rather than December to provide a more accurate measure of the post-hunting deer population.
(Click here to read entire Survey)
Aerial Infrared Survey for White-tailed Deer Feb – March 2009

The goal of the project was to conduct a population census within each of 17 zones to better manage white-tailed deer in Delaware. The purpose of the aerial infrared survey was to locate and map the group locations and enumerate deer found within each group within each of the 17 survey blocks established. Vision Air Research, Inc. was contracted to conduct the surveys by the DNREC Division of Fish and Wildlife. Survey flights were conducted February 23 – March 10, 2009.
(Click here to read entire Survey)
Herd Monitoring is another important building block of QDM. There are two types of data commonly collected ‹ harvest data and observation data. Harvest data should be collected from deer harvested during the season or found dead at other times. Observation data may be collected at any time, but generally collected while hunting. Together, these data help hunters and managers make educated decisions about their deer herds. Good records generally result in good management decisions, whereas poor or incomplete records often result in faulty decisions. It takes a substantial amount of data to develop a good “picture” of a herd. On many properties, the number of deer taken is too small and measurements are too variable for conclusions to be drawn from a single year’s data. Therefore, data must be collected over several years or combined with surrounding properties’ data to determine trends in herd condition.

Harvest Data
Harvest records are generally the most important information from which to base management decisions. However, management decisions are only as good as the quality of data gathered. Therefore, harvest data must be complete and consistently collected from every deer harvested. This should be made mandatory. If this is not possible, a convenient, well-equipped check station or shed to process deer will help encourage data collection.
When possible, one person should record all of the data while others process the deer. Data collected on both bucks and does include: date of harvest, sex, weight, age (jawbone), harvest location, hunter’s name, and any comments or unique observations. Additional data collected on bucks should include number of points, antler spread, antler length, circumference at the base, and possibly other details such as Boone & Crockett score. Additional data collected on does include evidence of lactation (“in milk”) and fetal information.

All jawbones should be retained until after the hunting season and provided to an experienced wildlife biologist for aging. With practice, hunters can become efficient at estimating deer age. Several resource materials on deer aging are available from the Quality Deer Management Association (QDMA).

Harvest data provide useful insight into the current condition of a deer herd. When compared to previous years, harvest data provide the opportunity to see where a deer management program has been and where it is going. This information is particularly useful in QDM programs that implement antler restrictions to protect young bucks.