Secret life of snags revealed

#MiddleburyCT #MiddleburyLandTrust #TreeSnags

The tree on the left is one of several snags that can be seen from the trail around Lake Elise. Such snags – standing dead trees – are a very valuable resource to all kinds of birds and animals and as such are an important part of the ecosystem. (Janine Sullivan-Wiley photo)

By JANINE SULLIVAN–WILEY

“Tree snag.” That just plain sounds yucky, and if you saw one, you might think that it indeed looks rather unglamorous. If you’re not familiar with the term, a tree snag is the remnant of a dead tree that remains standing. While you might not want to keep one in your front yard, they are such an important part of the ecosystem you might want to reconsider removing one in your backyard or woodlot. Tree snags are room and board establishments for many valuable critters.

First, I must acknowledge that a tall dead tree, full of its original branches, can be a hazard when it falls. If it’s near your house, you may have no choice but to have it cut down. But often, that’s not the case. And if the branches have mostly fallen off, the trunk remnant tends to be more stable. It is now a glorious snag, and that’s when the good stuff happens.

The best ones are at least six feet tall and at least 12 inches in diameter at chest height. Often the first to benefit from a snag are woodpeckers of many kinds as they mine the tree for insects (those insects may be part of why the tree died in the first place, or they may have moved in later). The drilling rat-a-tat-tats differ based on the species of bird. Once you learn the differences, you’ll know who is dining by the drill pattern alone. The Cornell Lab “Merlin Bird ID” – a free app – is great for identifying birds by sound. You also can identify them by their excavation pattern. The pileated woodpecker makes a characteristic vertical rectangular hole.

Woodpeckers get the party started. Once their holes are made, other birds may move in. Holes in dead trees are the original blue bird houses. The holes also are used by two of our smaller owls: screech owls and saw-whet owls. The natural decay process and added excavation makes for bigger cavities, which can then be used by barred owls and great horned owls as well. Connecticut DEEP says more than 35 species of birds in the Northeast nest in these cavities.

It’s not just birds that live in the holes in snags. They can be home for flying squirrels. And, as the cavities enlarge, porcupines, raccoons and fishers may move in. (A naturalist I know aims his camera up inside hollow trees and has sometimes seen the backside of a porcupine up there.) Bats may roost inside or under loose bark.

Eventually the snag falls, often after deteriorating and becoming a shadow of its original structure. Once down, snags serve a whole new group: tiny mammals, reptiles, amphibians and all kinds of bugs. Fungi thrive on the organic matter, and at the end of the line, the snags become rich soil on the forest floor.

The next time you’re out in the woods, look for these ecological workhorses. Several wonderful examples can be found along the trail around Middlebury Land Trust’s Lake Elise. There are some that are newer and some that are older with a very well-used appearance.

For questions or comments, contact this writer at jswspotlight@gmail.com. You can visit the Middlebury Land Trust on Facebook or the website at middleburylandtrust.org to find plenty of great outdoor spaces to explore and information about upcoming events. Happy hiking!