Posted by Rebecca Johnson on October 3, 2006

Q: Where I live, we just experienced some extreme rainfall. I was just wondering what happens to little critters in burrows when it rains so hard. Do their tunnels flood? Does the soil soak up the moisture?

Becca

Habitat: forest/open woods

State: Virginia

Habitat: forest/open woods

A: Excellent question but I'm not sure much research has been done on the subject to find out definite answers to your question. The kind of soil that animals burrow in has a lot to do with whether or not they end up with water in their burrows. If water in a burrow is only temporary, an animal can crawl out and return as soon as the water drains away. I've seen some very wet chipmunks right after a heavy rain and figured they were forced to leave their burrows.

In sandy locations (Virginia has sandy soil in the eastern part of the state, I believe) the water can usually percolate down through the soil quickly and doesn't collect. In areas with clay soils that don't drain quickly, burrowing animals may have problems. In many cases, these animals will choose sites that are a bit higher to improve runoff. Of course this isn't always possible so if an area receives lots of rain and it can't percolate (run down through the soil and away)these animals end up with a burrow full of water. If there are babies in the burrow, these may drown but the adults can usually escape. You may have noticed in your yard after a big rain that in some places the water tends to stand for a while and in other areas it doesn't - again, it has lots to do with the kind of soil involved and whether a specific location is on the low or high side.

In areas where floods occur, large areas may be flooded for days at a time and in these cases, the animals must leave their burrows and climb to safety. Of course, this makes them much more vulnerable to predators and probably many don't survive.

Hope this answers your question a wee bit. Thanks for asking.

John Wiessinger ( October 4, 2006)