Tag Archives: forest birds

Surveying Wildlife at Elm Hill

In order to characterize the bird community at Elm Hill, point count surveys were performed at 24 locations within forested areas of the sanctuary.  During a ten minute period, the species of each individual bird is recorded, as detected by sight or sound, within 50 meters.  This gives us information on the abundance of each species and the overall species richness (number of species).  As is typical, each location was surveyed 3 times, and this yielded 789 detections of birds representing 51 species!

As discussed in previous blog posts about the development of a Foresters for the Birds demonstration site at Elm Hill, these surveys were done to establish a pre-management baseline, which will then be compared with conditions after management.  Wait a minute… 51 species!?!  Is management really necessary?

51 species may sound like a lot, leading to the conclusion that the forests are already providing good habitat.  That may be true, but for what species?  Upon closer examination of the data, we can see that many of the species we recorded (e.g., nuthatches, titmice, and catbirds) are quite common, thriving in our woodlands and backyards alike.  Others, such as Barred Owls, naturally occur at low densities, so we wouldn’t expect to find many of them.

It’s those species that we conspicuously did not detect, or recorded very few of, that we are managing for.  For example Black-throated Blue Warbler and Ruffed Grouse were not recorded.  These species rely on some degree of disturbance to the canopy, creating vegetative growth in the understory and a mix of tree ages in the forest.  These are conditions that can be created through sustainable forestry, and it would not be unreasonable to expect these, and other species of conservation concern, to show up at Elm Hill after appropriate habitat management.  Time will tell.

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In the Field: Elm Hill

Scarlet Tanager © Ruby Sarkar

Past blog posts about our Elm Hill Sanctuary – a Foresters for the Birds demonstration site—have largely discussed the planning of forestry practices to manage and enhance bird habitat.  We kicked the project off last fall and winter, when our migratory birds were hundreds or thousands of miles away.  So, until spring arrived, we were not able to work much with the birds themselves.

A primary focus of the program is indeed birds and their habitat, so it is important to assess how effective any implemented forestry practices are.  This enables us to make adjustments to future management and maximize the benefit for birds.  We do this by monitoring how the birds respond.  At the earliest, on the ground management at Elm Hill will not happen until this coming winter.  However, we will need to compare the future bird response to current, baseline conditions.  A before-and-after, if you will.

Late May through early July is the ideal time to sample breeding birds.  Migration is over, so all the birds have arrived and will likely remain through the season.  They are on breeding territories and actively singing, which helps us to detect their presence.  During this time we can begin to answer some important questions.

For example, which species are present, and what are their general habitat preferences?  How many species are present?  How many individuals of each species are present?  Is a particular species absent that we may have expected?  Answering questions like these help us to characterize the current bird community.  Answering the same questions after habitat management will help us assess just how effective our efforts were.

Wood Thrush nest © Michael Ross

This is why, with the help of volunteers, Sheila Carroll and Mark Lynch, we recently completed a series of point count surveys at Elm Hill, all within areas that are slated for management in the near future.  With this initial information in hand, we will eventually see how things change after management, which is geared towards helping species in need of conservation action.  The next step will be to dig into the data, and some results will be shared in future Elm Hill updates.  Stay tuned!

Please consider supporting our bird conservation work by making a donation today. Thank you!

Old Baldy Gets a Haircut

By Tom Lautzenheiser, Central/Western Regional Scientist

Mass Audubon’s Old Baldy Wildlife Sanctuary in Otis offers visitors with a rare view in south Berkshire County: a near 360-degree panoramic view from the summit of its eponymous hill. The landscape below is nearly entirely forested, with few interruptions. The clearing at the summit itself was expanded around 2000, when a previous landowner sought to subdivide the property, and at the same time the forest growing on Old Baldy’s sides was heavily logged. The resulting overlook is a gem in the Berkshires.

The forest harvesting, while completed for economic return, resulted in a conservation benefit because it created much needed habitat for young-forest associated wildlife species—many of whom are experiencing steep long-term population declines throughout the region due largely to habitat loss. In the years following the harvest young-forest species like Chestnut-sided Warbler, Indigo Bunting, White-throated Sparrow, and Eastern Towhee, thrived in the thicket.

Female Eastern Towhee © Susan Wellington

However, in recent years the canopy has been closing as the trees grow, and this crucial habitat has been disappearing.

With the successional clock ticking, Mass Audubon sought and was awarded a Habitat Management Grant from the state Division of Fisheries & Wildlife, which funded the maintenance and expansion of the clearing at Old Baldy in the early spring of 2017.

Old Baldy following the 2017 clearing of trees to create habitat

The loggers did their work well, though the transition appears shocking, with stumps and downed tops strewn as after a storm, and the remnant trees seeming thin and lonely over the slash. Importantly, however, increased sunlight on the ground will stimulate a flush of sprouting, and within a growing season or two the cleared area should be lush with brambles and tree sprouts, again forming the dense cover favored by many species of conservation concern. Within a few years the site will again be prime habitat supporting populations of young-forest birds. Many other wildlife species, including white-tailed deer and black bear, will also find food and shelter in the cleared area.

Until the dense regrowth sprouts up, visitors may notice large brush piles scattered throughout the site. These brush piles are supplemental habitat for New England cottontail, our native rabbit species that is of critical conservation concern.

Mass Audubon’s decision to maintain and expand a forest clearing at Old Baldy was not made lightly, but was made in recognition that without concerted effort, populations of dozens of wildlife species reliant on young-forest habitat will continue to dwindle in the state. Just as the views from the summit of Old Baldy were beginning to be obscured by maturing trees, habitat quality for young-forest species was also declining, and active intervention was necessary to secure the area’s value for these species.

It was time for Old Baldy to get a haircut. And like a haircut, the trees at Old Baldy will grow back, without substantially affecting the land underneath.

 

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Tree cavities: home to many creatures

When we think about a bird’s nest, we usually conjure up the image of a cup-shaped tangle of twigs and dried grass, with perhaps some moss or strips of bark, cleverly placed in a bush or the limb of a tree.  Maybe that’s because these are the most visible types of nests, whose remnants are easily seen when the leaves drop each fall.  Nests of other birds a quite difficult to see, even in plain sight.  For example, the Piping Plover creates a just slight depression in the sand, and the Eastern Whip-poor-will nests directly on the forest floor, each with highly camouflaged eggs.

Yet another type of nest are those placed in the cavity of a tree.  Many common bird species are actually cavity nesters, including nuthatches, chickadees, titmice, bluebirds, woodpeckers and some owls.  Cavity nests provide protection from predators, shelter from weather events, and can be chosen with respect to the regional climate.  For example, in northern latitudes woodpeckers are known to orient their cavities south towards the sun, so that their young will stay nice and toasty in the nest.

Pileated Woodpecker family; adult male on left, female on right. © Kim Nagy

Woodpeckers are particularly important in the world of cavity nesters.  While cavities can occur naturally in trees, most species are poorly suited to excavate their own cavities, and often rely on holes created by woodpeckers.

Cavities usually begin with a fungal infection, which creates a soft inner wood that is easy to excavate.  This condition is most common in older dying trees, which eventually become dead standing trees (called snags) and continue to be a good resource for cavity nesters.  Unfortunately, dying trees and snags present inefficiencies to timber production, and a history of land clearing and forestry practices have limited snag numbers.  Meanwhile, populations of woodpeckers and other cavity nesters can suffer if there are too few cavity trees available.

The good news is that forestry can also help to increase the number of cavity trees.  For example, the maintenance of large dying trees and snags is promoted by Mass Audubon’s Foresters for the Birds program.  This program, a partnership between Mass Audubon, MassWoodlands Institute, and the Mass Department of Conservation and Recreation, provides assistance to landowners who wish to manage their woods for bird habitat with sustainable forestry practices.

Empowering private landowners is critical because they own the majority (75%) of forests in Massachusetts.

— Jeff Ritterson, Forest Bird Conservation Fellow, Mass Audubon

Northern Flicker (yellow-shafted) adult female with young in cavity nest © Cynthia Rand

Please consider supporting our bird conservation work by making a donation today. Thank you!