Wildlife Trees

Snags. They may just be the most alive tree in the forest.

Have you ever noticed how dead and decaying trees are actually teaming with life? There are several dead trees standing on our property. The forestry term for this is snag but a more deserving term is wildlife tree. This dead wood brings a lot of life to our garden, attracting wildlife that use them as nesting places, storage areas, for foraging, roosting and perching.

It usually starts with cavities excavated by woodpeckers, as they rarely use nesting boxes. Woodpeckers are made to dig. They have thick-walled skulls, powerful neck muscles, chisel like beaks and sharp feet with curved nails, which they use to skillfully construct holes for nesting.

Red headed woodpecker on a snag

Downy woodpecker investigating an empty cavity

They typically create several holes each season and rarely nest in the same one twice. We have 7 different species of woodpeckers in our garden, some are year-round residence and others seasonal.

As woodpeckers create new homes, the empty cavities become available for secondary cavity nesters such as bluebirds, chickadees, nuthatches, house wrens, squirrels, bats, raccoons, opossums, flying squirrels and owls, who can not excavate their own cavities.  

fallen snag showing two nesting cavities
Have you ever notice leaf nests high up in trees or bird houses stuffed with nesting materials in winter? Those are squirrel homes when cavities are not available. The survival of young squirrels in leaf nests is less than half that of cavity housed squirrels.  Even snakes that shed their skin would rather slither into a safe cavity than be out in the open where they are vulnerable during the molting process.

dead bark nurtures insects which attract insect-loving birds
The dead bark on decaying trees nurtures insects, which attracts insect-loving birds. Nuthatches, and woodpeckers eat bark beetles, spiders and ants that are found on the surface of the bark. Woodpeckers also find larvae and pupae of insects in the inner bark of snags and pileated woodpeckers dig down to the heartwood to prey on carpenter ants and termites. Snags are an open buffet for these birds.

The space between partially detached bark is where butterflies find shelter, often overwintering there. It also provides roosting slits for some songbirds and bats. The birds of prey that frequent our property (hawks and owls) are particularly fond of perching on top of one of the tall snag in our woods, allowing a clear view for hunting the land below.

The top of one of our snags came tumbling down in the wind the other day. The moss and fungi blanketing the trunk was already a clear sign that this snag was severely weakened and ripe for its next purpose. Think about it, these decaying trees and fallen logs may just actually be creating and influencing more organisms than the living trees.

soft snag covered in fungi and lacks limbs

Skinks, fence lizards and tree frogs will take up residence in the soft wood, enjoying the cool wet temperatures found in these logs.  Carpenter ants, wood-boring beetles and termites assist in breaking down the wood.

Squirrels and mice will hide nuts in the loose fibers. As the log continues to decay by fungus, microbes and insects it will eventually become humus providing a nutrient rich environment for seedlings to grow. 

The fallen limbs that lay scattered on the forest floor can also provide a safe haven for quail, turkeys and other ground birds while cavities and nooks in standing trees provide places to animals and birds to sleep and escape from the elements. Snag loving mammals in our woods include bats, flying squirrels, fox, raccoon, opossum and gray squirrels.

tree cavities providing shelter for animals in our woods

Snags are a natural feature that provide a unique environment for wildlife. To some gardeners dead and decaying trees may not be the most attractive of trees, but that all depends on your perspective. A snag can become a striking feature in your landscape with its interesting structure and texture.  If you don't like the look of a dead tree or your HOA won't tolerate one, you can pretty it up by training a native vine to grow around it. For us, they ensure that our garden will remain filled with wildlife.


  1. Wildlife trees - love that term! I love every one that I have and secretly yearn for more.

  2. Excellent description of the importance of dead and decomposing trees in the landscape. When trees fall in our woods, we leave them in place. I'm sure the neighbors wonder about it, but oh well. It's pretty wild back there anyway. I find the woodpeckers fascinating, too.

  3. And the cycle of life goes on… When I visited the Wheeler National Wildlife Refuge yesterday, I noticed a number of snag trees. They were filled with wildlife. Thanks for an informative and well-written post!

  4. I love this term too Karin. When we have to cut down trees, we leave many snags for wildlife instead of cutting them down all the way.

  5. I love looking at fallen or decaying logs in the forested area behind our house and whenever we go on nature hikes - you never know what you will find.

  6. Such important info.... Great post... Michelle

  7. Here in the suburbs it's hard to have a snag. When a street tree dies I no longer report it to the City because I figure the longer it stays, the better. The top 10' or so of a neighbor's eastern red cedar fell into our yard and I secured it to the back fence. It's not really big enough to provide nesting sites, though.

    1. Having wildlife trees in human dominated areas are often considered dangerous and an eyesore but its doable as you've demonstrated even though they may not be fully serviced. I've read about campaigns in the Pacific NW promoting snags in suburbia, where they are needed most. Professional arborists come in an create snags out of live trees in gradual or rapid techniques.

  8. They are so very important to wildlife and a good post. Just a trick you might not know that a birder taught me. Take a stick and tap the bottom of the trunk. Out will pop the inhabitant.

  9. 'Snag' - now there's a term I haven't heard in years. Great story about their purpose and usefulness, and great shots of the woodpeckers.

    Brace yourself for the winter storm. I'm glad to be further south where I just planted a Dutchman's Pipe today - looking forward to seeing the butterflies.

  10. I see Pileated woodpeckers on the dead trees on our property all of the time! Several tulip polars in the grove about the house died and Pileated have carved cavities in those.

    I agree with Deb, a very well-written and informative post!


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One of my favorite things about blogging is the conversation with readers. Leave a comment and let's get talking. ~Karin

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