Identifying Vertebrate Damage to Gardens, Crops, and Grass

This page contains a series of questions that will help guide you in determining the wildlife species that is damaging your lawn or garden.

What is the location of the damage?

1. garden damage
2. grass and ground damage:
   • furrowing
   • shredding
   • holes
3. mounds of dirt

Garden Damage

Daytime Damage	Night and/or Day	Night-time damage
Birds Chipmunks Ground Squirrels Tree Squirrels Woodchucks	Pocket Gophers Coyotes Moles Rabbits	Deer Opossums Raccoons Rats Voles

Mounds of Dirt

Mounds are typically created by two different animals: moles and pocket gophers. Mole mounds are circular and tend to be smaller, 6-8 inches in diameter. Pocket gopher mounds tend to be kidney- or teardrop-shaped and will be larger, 10-15 inches in diameter.

Top view of Mole and Pocket Gopher Mounds
Side view of Mole and Pocket Gopher Mounds

Small dirt mounds like this one signifies earthworm scat. They can be distinguished from crayfish mounds because there is no chimney like character to the mound. To confirm the mound is from worms, scrape away the mound and look for a 1/4-inch size hole in the ground. This photo is courtesy of Julie Goldman, NY.

Furrows or Grooves

Furrows are areas of grass or soil pushed up from below that follow a line.

Grooves are lined depressions in the soil or grass.

Furrows can be long and straight or short and bent. Furrows are caused by Moles.
Voles will create trails in the grass where they travel. Photo courtesy of Stephen M. Vantassel
Another example of vole damage to grass. Photo courtesy of Stephen M. Vantassel.

Shredding

When does the damage occur?

• Day
• Night

Day

Birds: Identifying a specific species causing lawn damage would be very difficult, but bird damage on lawns may be distinguishable from skunk damage by

1. time of year – bird damage tends to occur in the fall
2. grass will be fluffy – a bird has to grab grass with its beak and then pull, move, and drop it. Skunks can claw, shift, and press. A lawn damaged by skunks will still have holes but the grass will be pressed down not strewn about on the surface.

Photo is of damage caused by grackles, taken by Stephen M. Vantassel.

Night

Armadillos: This photo, by Michael Merchant of Texas Extension, shows that armadillo damage can be extensive. However, armadillos are more precise in their digging. Raccoons just shred the sod in their cumbersome hunt for food.
Raccoons: Raccoons will shred or roll the grass in search of grubs and worms. This photo by Christ Percha is an excellent example of how badly a raccoon can tear up a lawn.
Skunks: Skunks are very precise in their digging. They will make individual cone-shaped holes precisely at the spot where the grub or other insect is. Photo courtesy of Rob Erickson of Wildlife Control Technology Magazine.