Aerial Deer Survey: Population Increasing

Survey results indicated that Connecticut's deer population is increasing, with an estimated winter population of 76,344 deer

The Wildlife Division monitors the statewide deer population by a variety of methods, including harvest data, deer hunter surveys, deer-vehicle collisions, homeowner complaints about deer damage and aerial deer surveys. A statewide aerial deer survey is conducted by helicopter, once every three years, on calm days with complete snow cover to maximize the visibility of deer.

When assessing aerial deer survey data it is important to remember that many parameters may affect the visibility of deer, including pilot skill, observer experience, wind speed, temperature, timing of survey and snow conditions. Due to these parameters, there may be a high degree of variability between survey periods. In addition, the aerial deer survey samples about one percent of the total deer habitat in the state. Therefore, trends in aerial surveys should be interpreted using at least three to five survey periods (9 to 15 years) rather than comparing data from one year to the next. The current survey technique and sampling scheme have been used since 1993. The survey technique is most useful as a long-term trend index determining whether the deer population is increasing, stable or decreasing.

The most recent aerial deer survey was initiated during January 1999, but was not completed until February 2000 due to a lack of snow cover.

Survey results indicated that Connecticut's deer population is increasing, with an estimated winter population of 76,344 deer. The 1999-2000 aerial deer survey population estimate was higher than the estimates from past aerial deer surveys conducted in 1993 (49,472) and 1996 (53,955). Although the deer population appears to be increasing, additional surveys are required to determine the rate of growth (see graph).

Results from the 1999-2000 survey indicate that Connecticut has an average deer density of 21 deer per square mile. In 1993 and 1996, mean deer densities were 14 and 15 deer per square mile, respectively. In Connecticut's 12 Deer Management Zones, the relative deer densities (deer/ mil) ranged from 5.3 to 40.3 deer per square mile. The highest densities were found in zones 11, 6 and 5. The lowest densities occurred in zones 10, 2 and 4. Although some zones have low overall deer densities, these areas can contain pockets with higher deer densities.

To address increases in Connecticut's deer population, the Wildlife Division has lengthened deer seasons, liberalized bag limits and encouraged the harvest of antlerless deer in high deer density areas that .have been identified through the data collection process. Wise deer management results in healthy deer populations and productive wildlife habitat.

Harvest data, deer hunter surveys, deer-vehicle collisions and homeowner concerns indicate that Connecticut's deer population is stable or slightly increasing. To continue the wise management of Connecticut's deer population it is important to collect a wide variety of biological and non-biological information. The aerial deer survey is an important component of Connecticut's deer management puzzle. - DEP