Foresters for the Birds Project Takes Flight
By Allaire Diamond
Taking "a bird's-eye view" often connotes seeing something from the air, from far away, where large landscape patterns supersede the subtleties visible at close range. Migrating birds traversing continents and vast ecosystems on their spring and fall journeys certainly interpret landscapes on such an elevated scale, and major stopovers such as Cape Cod, the Chesapeake Bay, and Vermont's own Dead Creek attract hundreds of thousands of birds each year.
Yet when it comes to choosing a nest site, forest-dwelling birds train their eyes on quite a different landscape. They can identify trees, calculate the angles of branches, measure overstory closure and assess the amount of coarse woody material on the forest floor. They measure many of the same things that foresters account for when cruising woodlots and writing management recommendations. And like foresters and forest landowners, birds do it because a forest is an investment for the future. Each bird species will only commit the significant time and energy to build a nest if it thinks conditions are exactly right.
With such similar skills and goals, foresters and bird biologists are collaborating on mutually agreeable forest management. In 2011, such a collaboration came to fruition in the form of the guide Silviculture with Birds in Mind, a product from the Foresters for the Birds collaborative project between Audubon Vermont and the Vermont Department of Forests, Parks and Recreation. Its purpose is to give foresters a bird's-eye view of how their silvicultural practices can affect, and improve, habitat for migratory forest-nesting species of conservation concern. With subtle shifts in forest management, nesting habitat for the project's twelve focus bird species (the 'Birder's Dozen') and others can be dramatically improved.
The Birder's Dozen
The black-throated blue warbler fashions nests of bark strips and spider webs in sapling or shrub branch forks. Scarlet tanagers build their cup nests on horizontal branches high in a tree's canopy. Yellow-bellied sapsuckers nest in rotten tree cavities, preferably those of quaking aspen over 13 inches in diameter, while veeries nest on the ground or in brush piles, in cups formed of leaf mold, dead leaves and bits of bark.
These four species are part of the Birder's Dozen, a subset of a group of 40 birds that Audubon Vermont has prioritized for habitat conservation. The Dozen depend on a wide range of forest types and breeding conditions; are in decline or at risk of decline, but not yet threatened; nest preferentially in the Northern Forest; and are easy to identify. When people focus on improving habitat for the Birder's Dozen species, other birds and wildlife benefit as well.
Foresters for the Birds suggests silvicultural treatments that could enhance habitat for these species while still managing a timber resource.
In the VLT-owned Mud Pond Forest in Greensboro, well-stocked stands of mixed hardwood rise over ridges and descend to a cedar swamp surrounding Mud Pond. Black-throated blue warblers, black-throated green warblers, winter wrens, least flycatchers, and ovenbirds call this forest home. This winter, a timber harvest is planned here, and VLT Stewardship Forester Dan Kilborn is hoping it will improve habitat for these birds as well as sustainably generate income for VLT for generations to come. Along with Pieter van Loon, VLT's Director of Forest Stewardship, and over 100 other foresters from around the region, Dan participated in Foresters for the Birds trainings and is hoping this project will demonstrate the value of a bird-minded approach. He is especially struck with "how different species use different components of the forest" and credits the program with helping him zone in on specific bird habitats.
To prepare the Mud Pond timber sale, Dan first worked with Audubon Vermont's Kristen Sharpless to inventory the area for birds and bird habitat features such as snags, midstory vegetation and canopy gaps. When the inventory was complete, Dan drew on the recommendations in Silviculture with Birds in Mind to develop a harvest plan.
When the harvest begins, the logger will use a cut-to-length system in the woods and leave coarse woody material, tree tops, and brush behind, providing habitat and forage material for forest birds. Logs will leave the woods on a forwarder, not a skidder, resulting in less ground disturbance. Low-vigor trees will be harvested to leave behind healthy 'crop trees' and create canopy gaps within the stand: these openings attract the insects that form much of the diet of warblers and flycatchers. In other parts of the forest, Dan prescribed Variable Retention Thinning, which will begin the process of turning an even-aged forest, where trees are largely the same age with a consistent continuous canopy, into a multi-aged forest, with much more diversity of tree size, height, midstory structure, and canopy closure. Because yellow-bellied sapsuckers nest here and prefer aspen snags, Dan prescribed leaving most aspen behind, knowing that these short-lived trees will become snags soon enough. The Mud Pond Forest is an official demonstration site for Foresters for the Birds, and Dan will partner with Audubon Vermont to measure the impacts of management on bird populations over time.
As a professional forester, Dan appreciates how "forestry with birds in mind" does not require drastic changes in traditional management practices to improve bird habitat, especially in stands that are being managed for multiple age classes: "there's nothing major most foresters have to change to manage in this way," says Dan.
Missing links, collaborative solutions
Foresters for the Birds 'hatched' on the VLT-conserved Sterling Town Forest in Stowe. Mike Snyder, Vermont's Commissioner of Forests, Parks and Recreation, helped initiate Foresters for the Birds after experimenting on the land when he was Chittenden County Forester. Mike's goal was to create more diverse structure in this forest, whose timber is of lower quality than at Mud Pond Forest, due to past history as well as wetter, heavier soils. He found that silvicultural guides didn't have strategies for achieving his goal. Around the same time, he attended a bird presentation with Audubon Vermont and realized just how engaging and accessible birds and bird habitat could be. It struck him that if one could manage for structure, as he was trying to do, one naturally incorporated bird habitat into a forest stand.
Thus began a partnership between Audubon Vermont and the Department of Forests Parks and Recreation. Scientists and foresters (including Pieter and Dan) from around the region listened and shared knowledge to develop specific, practical, truly collaborative strategies that not only filled in gaps that exist in silvicultural literature, but have the potential to expand the pool of landowners practicing forest management. As Mike emphasizes, describing a moment where he watched 50 foresters gazing through binoculars into the forest canopy, "people are amazed by birds." Foresters for the Birds helps "bring foresters and landowners together in a new way, around the tremendous goodwill generated by wildlife and songbirds in particular."
VLT Stewardship Foresters were early adopters of 'silviculture with birds in mind'. "Applying the Foresters for the Birds practices to our Mud Pond Forest property gives us the opportunity to showcase a standard of forestland stewardship that we hope others will view and consider for use on their own properties" explains Dennis Shaffer, VLT's Vice President for Stewardship. As the concept gains recognition within and outside Vermont, VLT will continue to demonstrate leadership. With easements on about 7% of Vermont's forestland, the land trust has a unique position from which to promote bird-minded stewardship practices and landowner-forester relationships.
Bringing the birds home
All forest landowners can manage their woods with birds in mind. The Forest Bird Initiative offers Foresters for the Birds, which is designed primarily for foresters, and also includes habitat assessments, workshops, field tours, and resources for landowners, as well as science and policy work. The Initiative provides a forum for landowners to connect with like-minded foresters and begin practical management on the ground. Kristen Sharpless, the Audubon biologist who helped develop the Foresters for the Birds project and also conducts habitat assessments, sees the project as a bridge to management for forest landowners whose primary concern is wildlife. At Audubon, she meets many landowners who, caring deeply about birds and other wildlife, take a 'preservationist' approach to their land, not wanting to disturb habitat through timber harvest. Yet preservation does not generate reliable income, and these landowners may end up selling off portions of their land for financial reasons, which has far graver implications for bird populations than thoughtful management. This approach may also result in a more homogeneous forest with diminished habitat resources.
"We want to engage landowners in keeping forests as forests," she says. "Carefully planned and thoughtfully implemented management can be a sustainable, long-term way to offset the holding costs of land." By managing with birds in mind, landowners can "improve habitat while investing in their land's ecological and economic productivity." When a bird-loving forest landowner hires a forester or enrolls in the Use Value Appraisal program for the first time, Kristen chalks up a victory for the project, the birds, and the forest.
In addition, Sharpless notes that the management strategies recommended by Foresters for the Birds can improve some residual forest conditions left over from Vermont's agricultural heyday: simple, young pole stands that hold little benefit for forest birds who need a "messy, complex, structurally diverse forest." This program offers practical tools for valuing the 'bird's eye view': what can look patchy and chaotic to a human will attract songbirds who visualize instead a safe and abundant home.
|Species||Desired forest condition|
|American Woodcock||Hardwood or mixed-wood forest matrix with a mix of openings and young forest, near shrub wetland|
|Black-throated Blue Warbler||Hardwood and mixed-wood stands with 50-80% canopy cover and dense understory|
|Black-throated Green Warbler||Well-stocked, uneven-aged mixed-wood and softwood saw-timber stands with >80% canopy cover|
|Blue-headed Vireo||Well-stocked, uneven-aged mixed-wood and softwood saw-timber stands with >80% canopy cover|
|Canada Warbler||Mixed-wood stands with 50-70% canopy cover, dense understory and midstory, and uneven forest floor|
|Chestnut-sided Warbler||Well-stocked hardwood seedling-sapling stands >1 acre with <30% canopy cover|
|Eastern Wood-Pewee||Hardwood pole/saw-timber stands with >80% canopy cover, gaps, and open midstory near openings and edges|
|Scarlet Tanager||Well-stocked, uneven-aged, hardwood saw-timber stands with >80% canopy cover|
|Veery||Hardwood stands with 30-80% canopy cover and dense understory near wetlands and/or riparian areas|
|White-throated Sparrow||Uneven-aged mixed-wood and softwood saw-timber stands with openings, <50% canopy cover and dense understory|
|Wood Thrush||Well-stocked, uneven-aged saw-timber hardwood stands with >80% canopy cover and moist leaf litter|
|Yellow-bellied Sapsucker||Hardwood and mixed-wood saw-timber stands with 30-80% canopy cover and dry hardwood snags or live trees with central decay|