Here’s What Drought is Doing To Wildlife and Habitat Now

From the U.S. Drought Monitor…

Brutally hot and dry weather again this week kept dryness entrenched across Texas, southern Oklahoma, Louisiana, and southern Mississippi. For the past 2 months, temperatures averaged 4 to 8 deg. F above normal from most of the Four Corners States eastward through most of Texas and Louisiana, and across southern Mississippi. A solid swath of extreme to exceptional drought (D3-D4) is now entrenched from central Texas eastward through most of Louisiana and southern Mississippi, expanding slightly northward as well.

Almost 80 percent of the Oklahoma cotton crop is in poor or very poor condition, as is 61 percent of Texas cotton. Peanuts, sorghum, soybeans, and rice planted in Texas, Louisiana, southern Oklahoma, and southern Mississippi were also being stressed by from heat and lack of rainfall, although the proportion in poor condition or worse is considerably lower. In addition, deteriorating pastures and rangelands are stressing livestock. As of early September, 72 percent of Texas rangelands, 63 percent of Louisiana pastures, and almost 40 percent of Mississippi pastures were in poor or very poor condition.

According to the NOAA National Integrated Drought Information System (Drought.gov) 90% of Louisiana is currently experiencing drought conditions with 77% of the state experiencing severe to exceptional drought conditions. July 2023 was the second hottest July on record (average temperature) since 1895 (National Centers for Environmental Education; ncei.noaa.gov).

Here is a summary of some of the repercussions experienced by wildlife from the Louisiana Department of Wildlife and Fisheries:

Water birds

Reduced areas of water at a landscape level can result in concentrations of water birds wherever there is sufficient water, and the water that is present can become stagnant and have poor quality. Artificially high concentrations of ducks, or any species, increases the risk of widespread disease transmission and reduces the effort required by local predators. Excessive heat also increases physiological and behavioral thermoregulatory costs. Stressed plants (both natural and agricultural crops) which serve as the food source for waterfowl throughout the winter will be less productive. For locally breeding ducks, evaporation of isolated ponds or pools where non-volant broods (those incapable of flight) are growing significantly decreases survival, as they must travel overland to alternative ponds. Both predation and malnourishment during this travel may result in mortality.

Deer

Drought affects the growth of plants utilized by deer for food and cover. Actively growing plants are more nutritious and better withstand the effects of herbivory. This is important if deer are to reach their growth and reproductive potential. Drought timing and severity has also been linked to increased bluetongue virus (BT) and epizootic hemorrhagic disease (EHD) outbreaks. The environmental conditions caused by drought have been correlated with higher insect vector populations that transmit the disease. Overall, deer in Louisiana have coped well with past drought events based on physical data collected from hunter-harvested deer. However, the timing and duration of droughts can have impacts.

Turkey / Quail

Dry conditions (below average rainfall) are often desired during nesting and brood rearing periods for ground nesting birds across Louisiana and the southeast. Dry periods from April through June can often lead to above average reproduction for eastern wild turkeys by minimizing nest failures and poult mortality. The same is true for northern bobwhites during the months of June through August. However, excessive/extended drought conditions can have adverse effects to vegetation structure and insect populations that young turkeys and quail need to survive. Excessive drought conditions can also negatively impact seed and mast crops on which turkeys and other wildlife, including deer and squirrels, depend on throughout the remainder of the year. Lastly, drought conditions also limit water sources in some situations, thus concentrating wildlife and increasing the risk of predation and disease transmission.

Proper long-term habitat management practices and environmental stewardship will help to minimize the effects of drought and other weather extremes on wildlife populations. Maintaining diverse forested and grassland/forb habitats in various stages of succession, promoting native plants, and conservation of wetlands and broad functional riparian areas all help to minimize the impacts of environmental extremes on wildlife.