Nature’s response to flooding

Even if your home was not one of the many that sustained flood damage last month, you may be seeing effects of the area’s flooding inside your home and not realize it.

“A lot of animals, when it gets really soaking wet outside, are going to move to higher ground. If your house is on higher ground then you’re going to expect more animals,” said Rudy Mancke, the University of South Carolina’s resident naturalist. “Animals that have been forced out of their homes due to flooding are going to go somewhere else.”

That’s why many homes are seeing an increase in the number of cockroaches, spiders, small rodents and, yes – even those slithery critters without legs.

“I get calls from people all the times about snakes,” Mancke said. “They were just forced out of their homes and now they’re just trying to make the best of the situation just like human beings are.”

In general, large amounts of rain and flooding are major causes of death for many wild animals, said Tim Mousseau, University of South Carolina professor of biological sciences.

“There have been hundreds of scientific studies documenting impacts to birds, mammals and insects,” Mousseau said. “Many animals nest on the ground and flooding often leads to complete loss of eggs and young. Small animals that are unable to make it to high ground are often swept away and drown during flooding events.”

But some populations thrive on the extra moisture. Mosquitoes have been so rampant in Richland County that officials announced they will resortto aerial assault this month and will spray pesticides over most of the county. In fact, officials reported that mosquito landing rates in lower Richland County have reached more than 60 per minute, far more than the normal rate of four or five at this time of year. Other areas of Richland County also have high rates. Northeast Richland County’s highest landing rate was 38, officials said, and the highest landing rate along the Broad River floodplain, north and northwest of downtown, was 20.

“Mosquito populations have benefited and if you’re an animal that eats mosquitoes then you’re going to be real, real happy because this has been a boom for them,” Mancke said. “Standing water is not a good thing for keeping mosquitoes at bay and, of course, it’s still standing on the flood plain of the Congaree River. Anything that likes water, the populations are going to rise.”

That is, unless the animals that like water lost their homes in the flooding.

“Of course if you’re a fish living in a lake and the dam breaks, that’s it for you,” Mancke said.

If those fish were game fish, such as bream or bass, the dam can be repaired, water can be refilled and the fish can simply be restocked, Mancke said. However, other rarer species of fish found in small ponds in the area may not be so easily replaced.

“The fish that are rare, the oddball little fish – pygmy sunfish and some of the small catfish species – that are in old mill ponds, I don’t know that you can get them back,” Mancke said. “And there were quite a few old mill pond dams that were broken. Those little rare fish and freshwater shrimp and freshwater jellyfish – all these oddball things – they’re probably gone. To get them back would take a long time.”

However, nature has a way of taking care of itself, Mancke said, and what’s bad for one species may be good for another.

“I got a call the other day about one of the lakes where the dam burst and there were a lot of large fish – carp – living in the lake that died and now folks are seeing bald eagles coming in feeding on the remains of the carp,” Mancke said. “So you’re getting this opportunity to see this bird, that is normally around, pretty close up. This is a heyday for them.”

Larger animals, such as raccoons, possums and gray foxes, that had homes in the floodplain were most likely able to escape the flooding rather quickly, Mancke said, as were birds in those areas such as certain species of owls and hawks.

“Anything that can move and get up and out they probably did,” Mancke said. “The cocoons of a moth, the chrysalis of a butterfly, small snails – those kind of things, those were washed away rather quickly.”

The good news is nature can restore itself rather quickly, Mancke said.

“Nature isn’t good, bad or wrong, it’s just a wonderful system that is at work here,” Mancke said. “I don’t like to think about events as good, bad or wrong for certain species. Some gain, some lose, but things balance out long term. Nature is more resilient than we suppose and it comes back rather quickly.”

This story was originally published November 9, 2015 at 10:43 AM with the headline "Nature’s response to flooding."