Updated February 2018
With drought conditions in the Southern Great Plains, many people are curious to know if conditions affect deer populations and if there is anything to be done to mitigate potential effects.
Drought can cause at least some negative effects on forage quality and quantity. Deer rely heavily on forage such as forbs during spring and summer to meet nutritional demands associated with lactation and antler growth. If nutritional needs are not met, fawn survival is jeopardized and antler growth may be compromised for body maintenance. Reduced fawn survival can cause short-term reductions in overall deer population numbers because there are fewer fawns to replace adult deer mortalities. The lack of nutrition could also result in more spikes. Yearling bucks that are spikes during a drought year could end up becoming trophy bucks if they are able to meet their nutritional needs in successive years. Increased fawn mortality and reduced antler quality may be more prevalent in areas that do not receive rains early in the growing season. Timely rains early in the growing season create conditions where deer are able to meet or exceed their nutritional needs.
If drought continues into fall and winter, doe body condition could be poor enough during winter and spring that some does may not carry fawns to full term, potentially reducing the fawn crop the next year. Similarly, bucks could be in poor enough condition going into spring that antler quality is compromised the next year because it will take them longer to recover from the effects of the rut and reduced forage due to drought.
If vegetation is significantly reduced during late summer or early fall due to drought, August/September spotlight, camera and/or daylight cruise surveys may reflect higher deer densities compared to previous years. Most likely, this is not because deer densities increased; rather, there was better visibility during surveys or better response to bait during camera surveys than in past years. Survey results can be deceiving, so remember that surveys are only estimates.
As managers, we can have an impact on white-tailed deer populations through selective harvest. If necessary, adjust deer harvest depending on management goals and the condition of the deer herd. So what should we consider regarding buck and doe harvest during deer season in drought years?
Bucks have higher natural mortality rates than does, which is one reason why most knowledgeable managers try to harvest fewer bucks than does on a yearly basis. If managing for trophy-quality antlers, buck harvest should be conservative and only bucks with desirable antler size or configuration should be harvested.
If the manager’s goal is to reduce the overall number of deer in the herd or to balance buck-to-doe ratios, he or she should capitalize on the opportunity the drought created to have more impact and aggressively harvest does. Managers can really have a significant impact on the overall population through doe harvest during drought. However, if deer densities and buck-to-doe ratios are suitable, consider reducing doe harvest during deer season to reduce the risk of adversely changing population parameters.
Deer populations have endured drought in the past, and they will survive more droughts. However, managers should remember that white-tailed deer will endure drought better on properties with good to excellent deer habitat than on properties with lower quality habitat.