Wildlife damage to trees: what extension services describe
Deer, rabbits, voles, beavers, woodpeckers, squirrels, porcupines, livestock and moles each leave a different mark on trees. This page puts the marks the extension services describe side by side, with one page each for deer, rabbits, voles, woodpeckers and sapsuckers, tree squirrels, porcupines and beavers.
Checked against the sources at the bottom of this page on October 8, 2026. Rules, fees and pay change: the source has the last word.
This page reports what the official source says. It is not legal advice: ask the office named here. Control or removal of wild animals is regulated, and the rules differ by species, place and season; the state or provincial wildlife agency is the office that applies. The page describes what the sources say the damage looks like and the guards they list, and it does not say what to do about any tree or animal. For bats, nesting birds and other protected species met in tree work, see the guide on wildlife and the law.
Compared at a glance
| Animal | What the damage looks like | Source |
|---|---|---|
| Deer | Torn, jagged twig ends from browsing. Long strips of torn bark where bucks rub. See the page on deer damage. | Kentucky, Purdue, Iowa State, California |
| Rabbits | Clean cuts at about 45 degrees on twigs. Gnawed bark close to the ground, in winter and early spring. See the page on rabbit damage. | California, South Dakota, Iowa State, Purdue |
| Voles | Small, irregular gnaw marks at the soil line or just below, and gnawed roots. See the page on vole damage. | California, Kentucky, South Dakota, Purdue |
| Beavers | Small to fence-post-sized trees cut off with the look of a sharpened pencil, usually along the edge of a planting beside a stream. Purdue says they will gnaw almost any tree. See the page on beaver damage. | Purdue, Utah State, Maryland, North Carolina State |
| Sapsuckers and woodpeckers | A series of small holes, about 1/8 inch across, evenly spaced in rings around a limb or the trunk. Purdue says the holes lower timber value and can be entry points for disease. Hole sizes differ by source, 1/8 to 3/8 inch. See the page on woodpecker and sapsucker damage. | California, Maryland, Iowa State, Purdue |
| Tree squirrels | Bark stripped to reach the cambium, growing tips of young trees destroyed, twigs clipped for nests, piles of cone scales. See the page on tree squirrel damage. | California, Maryland, Utah State, New Hampshire |
| Porcupines | Bark stripped down to the wood, mostly in winter and often high in the crown, with grooved tooth marks about 5 mm wide. See the page on porcupine damage. | Utah State, Maryland, New Hampshire |
| Livestock | Wounds from stepping on buttress roots and scratching on bark, plus soil compaction at the base that limits small feeder roots. | Purdue and USDA Forest Service (FNR-216) |
| Moles | Do not feed on roots directly. Tunnels near young trees make air pockets that can dry out and stress roots, and may serve as runways for voles. | Purdue and USDA Forest Service (FNR-216) |
| Birds on shoots | Birds landing on and snapping off the tender terminal shoot, which causes the tree to fork. The source calls redwing blackbirds especially notorious. | Purdue and USDA Forest Service (FNR-216) |
Telling them apart
The University of Kentucky Extension workbook for Christmas tree plantations says to identify the culprit correctly before trying to prevent or control damage, and that this is relatively easy from the evidence at the site. It names tracks, droppings and burrow systems, the lack of uniformity in gnaw marks (voles), and the height of the damage. UC IPM puts the line between rabbit and deer damage at about 2 feet, the height rabbits can reach. South Dakota separates voles from rabbits by the bite size and where on the tree the gnawing sits.
Where to read more
The Purdue publication is aimed at hardwood plantations, the Kentucky one at Christmas trees, and the Iowa State and California ones at home landscapes, so the guards and figures they list differ with the setting. Where a source mentions poison baits, it says they are restricted-use pesticides; the guide on who may apply pesticides covers licensing. Bees in hollow trunks and other animals met on the job are not covered on this page. For the wider topic of wild plants and fungi on trees, see things growing on trees.
Animals, one page each
Open
Sources
- Purdue University and USDA Forest Service, Diagnosing and Controlling Wildlife Damage in Hardwood Plantations (FNR-216), read October 8, 2026
- University of Kentucky Extension, Kentucky Christmas Tree Production Workbook: Pest Control-Animals (FOR-27), revised March 1990, read October 8, 2026
- Iowa State University Extension, How to Protect Trees and Shrubs from Animal Damage Over Winter, read October 8, 2026
- South Dakota Department of Agriculture and SDSU Extension, Pest Update February 5, 2020, read October 8, 2026
- UC IPM, Pest Notes: Rabbits (publication 7447), revised August 2022, read October 8, 2026
- University of Maryland Extension, Woodpecker and Sapsucker Damage on Trees, updated December 13, 2023, read October 8, 2026
- UC IPM, Pest Notes: Tree Squirrels (publication 74122), August 2016, read October 8, 2026
- Utah State University Extension Forestry, Utah Forest Facts 038: Identifying and Preventing Porcupine Damage to Trees, read October 8, 2026
- Utah State University Extension and Swaner Preserve and EcoCenter, Beaver Tree Protection Information Sheet, read October 8, 2026