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Columbia Missourian

Extreme heat, drought putting Missouri wildlife in danger

By Kayla Kauffman
July 4, 2012 | 3:05 p.m. CDT

COLUMBIA — Missouri residents trying to escape the heat aren't the only ones affected by unusually hot temperatures and persistent drought conditions. According to wildlife experts, animals big and small are being negatively affected by this year's record-breaking weather.

The drought — not the extreme heat — poses the most significant threat to wildlife, said John George, wildlife regional supervisor at the Missouri Department of Conservation.


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In a drought, plant life suffers and food becomes scarce. Large animals, such as deer, must travel farther than they normally would to find food. The heat fatigues them and makes it harder for them to outrun predators.

However, George said, most deer will survive the heat. Animals that don't travel easily are at highest risk during periods of extreme heat, he explained.

"Heat distresses wildlife, just like it distresses us," said Dennis Figg, wildlife programs supervisor at the Conservation Department. "We can expect wildlife to be just as stressed as people and plants are."

Figg said many animals will start changing the time of their daily activities or go into a heat-related dormancy period. 

"A lot of animals are going to seek refuge in places and lay low, and do that for as long as they can," he said.

Missouri residents can expect large animals such as deer to be active, possibly traveling long distances outside of their normal hours to find food, while small animals that cannot travel easily, such as box turtles, will be inactive for a period of time.

Birds and bugs

George said that another noticeable effect of this summer's drought is the lack of insects.

"There are fewer invertebrates outside," he said. "Abundance is down because it has been dry for so long."

Part of the reason insect numbers are low is because many species need shallow, temporary pools of water for certain life stages, George said. When these are scarce, there will be fewer insects in the air.

While Missouri residents might be sharing a collective high-five about the lack of mosquitoes, George warns that it could have consequences.

"It makes life difficult for birds that eat them," he said. "Insects provide a huge part of the food web. Anything dependent on them will have a rougher time."

Avian ecologist John Faaborg said birds are clearly suffering from a lack of insect food this summer, noting that his bird feeders have been swarmed with hungry birds this season.

"Normally I don't even feed in the summertime, and I have had incredible traffic at my bird feeders," Faaborg said. He said he has seen a tremendous number of cardinals, chickadees and woodpeckers in his backyard — birds that usually only eat insects at this point in the season. While these birds can rely on seeds, limited food intake will make reproductive success challenging as they only feed insects to their babies.

The problem is even greater for migratory birds like warblers, tanagers and thrushes, which only eat insects and berries. Both of these food sources will be hard to find this summer because of the drought, Faaborg said.

While these species were probably fine during the beginning of the season, Faaborg said he expects they are having a much harder time now that the area is in a drought. These birds migrate to the area to breed, producing two or three broods in a season, then migrate south for the cold winter months. A drought makes nesting challenging, and birds may only be able to have one brood. Faaborg said late-nesting species and birds that are trying to renest are having the most trouble.

Keeping bird feeders full will alleviate some of the problems for seed eaters, Faaborg said, but little can be done to help most wild birds.

Even hummingbirds are less present in Columbia this summer. Missouri residents can usually catch a glimpse of tiny ruby-throated hummingbirds during the summer by putting out feeders filled with sweet syrup, Figg said. The drought, however, has changed this.

"Hummingbirds are just not coming to feeders this season," he said. "Feeders are getting hot rather quickly — and hummingbirds are staying closer to rivers and streams where they can stay cooler and have easy access to water."


Even bodies of water aren't safe from drought conditions. Prolonged extreme heat can kill entire populations of fish in ponds and lakes — a natural occurrence called a "fish kill."

Fish kills occur when a body of water goes anoxic, meaning it lacks the amount of oxygen needed to support life. When a body of water's temperature increases, its level of life-sustaining oxygen decreases.

Although fish can typically survive heightened temperatures in larger bodies of water, droughts can cause shallow bodies like ponds to heat up so significantly that some species can't survive. Catfish, bluegill and bass are some of the species most often wiped out by fish kills, though other species might lose about half of their populations, George said.

Fish kills aren't uncommon in Missouri. There have been four or five fish kills reported across the state this summer, which is not atypical, said Paul Calvert, fisheries field director for the conservation department.

Calvert said Missouri might see more fish kills than usual this season, adding that there is nothing people can do to stop fish kills from occurring in backyard ponds and small bodies of water.

Supervising editor is Scott Swafford.