Category Archives: Habitat Management

29% of America’s Birds Are Gone. What Are We Doing About It?

“Species extinctions have defined the global biodiversity crisis, but extinction begins with loss in abundance of individuals” —Rosenberg et al., Decline of the North American Avifauna (2019)

So begins the first comprehensive review of bird population trends since the mid-20th century. Summaries of the study are available via the New York Times and NPR.

The results were unequivocal: 76% of all bird species in the US are declining, some precipitously. Compiling on-the ground data from Breeding Bird Atlases revealed that the total number of birds in the US has fallen by 29% since 1970. Some groups fared worse than other over the five decades in question: shorebirds were down 37%, warblers were down by 33%, and aerial insectivores were down by 32%. And the total volume of birds in the sky, as detected by the national weather radar, was down 14% in the last ten years alone.

Rusty Blackbirds, an inconspicuous, clear-eyed relative of the more common Red-winged, underwent a population crash of over 93% over the past several decades. They are now rare enough that monitoring them is difficult.

This is bad news. Really bad news. But it’s possible to fight, and it’s even reversible. Scientists and conservation professionals have time-tested and proven strategies for stemming the tide of ecological decline, and the only obstacles are funding, public interest, and political will.

Mass Audubon continues to take a multi-pronged, species-specific approach to mitigate the damage in our state. Here are a few of the solutions we’ve already mobilized:

Habitat protection

Birds simply can’t exist without bird habitat. We protect 36,000 acres of bird habitat in Massachusetts through direct ownership, and another 6,000 through “conservation restrictions” and other legal protections against development.

We’ve recorded 149 species of bird breeding & raising their young on our wildlife sanctuaries– over two thirds of the total species in the state.

Landowner Partnerships

Where we can’t protect land through direct purchase, we find ways to ensure that it’s being used in bird-friendly ways. Many grassland species have healthy populations on agricultural land, and agricultural practices can make or break their prospects for survival. The same goes for forest birds living on land actively managed for timber; birds and forestry can coexist where sustainable practices are applied.

Mass Audubon encourages bird-friendly agriculture through projects like the Bobolink Project, incentivizing landowners to delay mowing hayfields until after Bobolinks and other grassland birds have completed nesting. The project compensates landowners directly for any profits lost due to delayed mowing, and the compensation fund is 100% donor-supported. In 2018, we saved more than 1,000 Bobolink fledglings from going under the mower.

Similarly, our Foresters for the Birds program pushes a bird-friendly approach to forestry in Massachusetts. One of our sanctuaries even acts as a demonstration site for how sustainable forestry and bird habitat go hand in hand.

Direct Habitat Management

Mass Audubon is directly responsible for managing between 40-50% of Piping Plovers (a federally Endangered species) in Massachusetts, a state with 1/3 of the Atlantic Coast population. We also are responsible for 20% of the state’s American Oystercatchers, and 40% of its Least Terns.

Since 1986, Piping Plovers have rebounded from 135 pairs to 680 pairs.

While the Cornell study showed shorebirds declining on a continental scale, conservationists in Massachusetts have known that shorebirds were in trouble since the middle of the last century. That’s why Mass Audubon developed our Coastal Waterbird Program to protect shorebirds through management, conservation, policy development, and education.

Science-based Advocacy

In the past year alone, Mass Audubon petitioned for three species to receive special legal protections from the state: Eastern Meadowlarks, Saltmarsh Sparrows, and American Kestrels. These petitions were based on our own monitoring of these species’ populations, which are in particular trouble and require intervention, as well as growing consensus among ornithologists.

We also speak up when legal frameworks for protecting birds are under attack. The rollback of the Migratory Bird Treaty Act last year was a major setback for bird conservation, and we spoke up.

Fight the decline with your donation today >

Foresters for the Birds: Starting work at Elm Hill

Habitat management work at Elm Hill Wildlife Sanctuary is underway! Elm Hill is our demonstration site for our Forestry for the Birds program, which we’re using to exhibit techniques for improving bird habitat with sustainable forestry.

Invasive plant removal has begun, and forestry operations will commence in a few short months. Following years of fundraising, planning, site preparation, data collection, and a minor setback, it’s all finally coming together.

Eastern Towhees like young forests and dense scrubby habitat. Photo by: Marco Jona

Bird-Friendly Forestry

Foresters for the Birds works with private landowners and consulting foresters to create and enhance bird habitat using sustainable forestry practices. In order to lead by example, Mass Audubon decided to showcase such practices at Elm Hill. Besides creating great habitat for birds, the site will be used to educate and engage with landowners, conservation organizations, state agencies, forestry professionals, and the general public.  In fact, we’ve already hosted a handful of events at Elm Hill, attracting about 100 people so far.

Young Forests and Tree Diversity Are Key

Following a Foresters for the Birds management plan, this round of management will create about 30 acres of young forest, a habitat type crucial to a group of birds categorically in decline, such as Eastern Towhees and Chestnut-sided Warblers. We will also improve tree species diversity in about 100 acres of older forests, and encourage layers of shrubs and saplings to benefit species such as Wood Thrushes and Black-throated Blue Warblers.

Creating Climate-Resilient Forests

Climate change has already started to affect Massachusetts forests, which complicates management strategies for bird habitat. The ranges of plant and insect species that certain birds depend on are shifting, and some are inevitably less resilient to an unstable climate. Bearing this in mind, we worked with the Northern Institute of Applied Climate Science (NIACS) to ensure that our management actions at Elm Hill were climate-smart. With their help, we’re identifying opportunities to adapt the forest– and the birds it supports– to future climate conditions.

Please stay tuned for opportunities to visit Elm Hill, where detailed discussions of our bird habitat and climate adaption actions can take place. There’s much more to it beyond what can be communicated in a short blog post!

Studying Forest Structure At Elm Hill

Our bird conservation staff spent the past week collecting data at Elm Hill Wildlife Sanctuary, our demonstration site for Foresters for the Birds. Since we’re using this site to show how responsible forest management can enrich bird habitat, we need before-and-after data to compare changes in vegetation and bird diversity.

Birds See Forests For The Trees

The physical structure of a forest directly affects which birds are found there. The amount of vegetation near the forest floor (or “understory”) changes whether or not the forest can host a whole suite species that nest near the ground, like Ovenbirds and Black-throated Blue Warblers. Forests with open midstories (the layer of vegetation between 5–50 feet off the ground) attract flycatching birds like Eastern Wood-Pewees, but dense midstories appeal to Wood Thrushes and Canada Warblers.

The goal of our work at Elm Hill is to demonstrate how every forest species has its own habitat preferences, and how thoughtful land management can create habitat for declining species. Since three quarters of Massachusetts’ forests are in private hands, it’s critical to make these lands as hospitable as possible to wildlife.

Collecting Vegetation Data

A data sheet we use for recording information about trees and forest structure at Elm Hill.

Before we alter any habitat at Elm Hill, we’re recording these factors at sites where we’ve previously done bird surveys:

  • Total woody biomass (i.e., the average size and number of trees in a given area)
  • Tree species makeup (i.e., which trees are there, and how many of each)
  • Canopy density (i.e., the amount of cover provided by leaves in the treetops)
  • Sapling density (i.e., the number of young trees from around 1–6 feet tall)
  • Coarse woody debris (i.e., the number of logs and slash piles on the ground)

We outline a 400-square-meter plot with ropes at every site to make sure we collect data from the same area of land each time. This works pretty well until somebody tangles the ropes:

Jeff tangled the ropes. It definitely was not me.

While measuring trees, logs, and saplings is straightforward, you might wonder how researchers measure canopy density— and the instrument for this is quite cool. A spherical densiometer (pictured below) condenses a wide view of the canopy into a small image (much like a fisheye camera lens) with a grid over it. By estimating the percentage of each grid square occupied by leaves or trunks (and adding them up, and taking readings in each cardinal direction), we have a standardized and simple way of measuring canopy density. This also works as a proxy for determining how much light reaches the forest floor.

A spherical densiometer, used for measuring the amount of leaves in the treetops.

Long-term Goals

After foresters have cleared the woods of invasive species and created a variety of spatial habitat types, we’ll be able to show what changes this brings to Elm Hill’s bird species.

Elm Hill contains mostly 70–90-year-old forest, like much of Massachusetts. We’ll manage parts of the sanctuary for birds that prefer young forest, which are in trouble statewide, and in other part’s we’ll try to mimic old-growth forest conditions, which would take over a century to emerge naturally. Hopefully, we can then use this site as a physical example of how foresters and landowners can improve bird habitat on the properties they manage.

 

 

Partnerships for Plovers: Birdlife International and Mass Audubon

An endangered Piping Plover at one of Mass Audubon’s coastal sanctuaries. (Photo by Will Freedberg)

 

This year, Mass Audubon is partnering with BirdLife International to help coordinate migratory shorebird conservation across the hemisphere. By joining the Friends across the Flyway initiative, Mass Audubon can link up with conservation organizations along the Atlantic Flyway to protect species shared across borders.

 

Connectivity Counts

For birds whose ranges cross international borders, it’s crucial that regional conservation groups coordinate with each other. All threatened or endangered shorebirds in Massachusetts spend half the year in migration or at their wintering grounds. Every year, Piping Plovers, Red Knots, and Least Terns migrate to Mexico, the Bahamas, and even Argentina—and they depend on stopover habitats to feed and “refuel” along the way.

Removing just one link in this chain of habitats can spell the demise for an entire population. When making a conservation plan, biologists like to emphasize “habitat connectivity,” or keeping open routes between areas where a species lives. With New England’s shorebirds, this means more than preserving a physical link between protected areas—it means conserving breeding habitat in Massachusetts, wintering habitat in the Southern Hemisphere, and key stopover sites birds use while migrating in between.

 

How We Help In Massachusetts

Mass Audubon’s Coastal Waterbird Program approaches local shorebird conservation from all possible angles. Firstly, Mass Audubon puts boots on the ground—or rather, on the sand—to monitor shorebird populations and develop science-based conservation plans. Then, we work with local and state governments to put those plans into action. This includes setting goals for shorebird recovery, res-siting energy projects, and helping lawmakers identify beaches where shorebirds are threatened by offroad vehicles.

So far, the program has been a huge success! Piping Plover numbers have quintupled in Massachusetts since the program started in 1984.  American Oystercatchers, once a rare sight in our state, now number over 200 nesting pairs.

 

Partnerships Save Species

We’re excited that our Coastal Waterbird Program is linking up with BirdLife and its partners! This suite of organizations can pool resources to protect habitat and produce research on these shorebirds’ global needs. To learn more about Friends across the Flyway, check out BirdLife’s video on Rowan, the cute Red Knot.

Wood Ducks Are Upon Us!

Photo © Will Freedberg

 

Every year, Wood Duck sightings swell in late March and April.  Some wintering birds always linger in Massachusetts, but most of our population is migratory, and only visible here during the breeding season.  The April pulse of Wood Ducks represents birds that breed to our north, passing through at the same time our local breeders arrive.

True to their name, Wood Ducks prefer flooded forests and wetlands with standing trees (or at least lots of cover). During migration, you can look for groups of them in more open water, and even on urban ponds.

A Population On The Rebound

Wood Ducks are doing well in Massachusetts, although populations in some parts of the USA are shrinking.  Overall, Wood Duck numbers are on the rise, despite the species’ precipitous decline in at the turn of the century.  In the late 1800s, the persecution of American beavers slowed the creation of wooded wetlands, and existing habitat was cleared or drained for agriculture. Unregulated hunting for Wood Duck feathers and meat continued into the early 20th century until their total extinction seemed like a real possibility.

Wood Ducks’ decline coincided with the dawn of the conservation movement, and bird-lovers, biologists and concerned outdoorspeople all rallied to bring Wood Ducks back from the brink.  Wood Duck protection was a strong motivator in passing the 1918 Migratory Bird Treaty Act—the keystone of legal protection for wild birds—which remains critical for Wood Duck populations today. Overzealous pesticide application after WWII dealt another blow to their population, which lasted into the 1970s. Luckily, Wood Duck populations have been on the rise again—in stark contrast with historically common species which faced ultimately insurmountable  threats (like the Passenger Pigeon).

Help Wood Ducks— Get A Nest Box

Nest boxes made their debut as a conservation tool during early efforts to protect Wood Ducks.  As cavity nesters that prefer sites high up and away from predators, Wood Ducks struggle to nest in wetlands without standing trees- but nest boxes provide a great alternative! If you live near a marshy wetland, consider building one or buying one at the Mass Audubon store.

 

 

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.

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

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.

 

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