Bear Creek Wildlife Sanctuary
Birding Community Newsletter

Issue 2017-16 | Friday, September 29 2017 | 1,583 Subscribers
Socked In
Unseasonably High Humidity Creates Heavy Banks of Fog that Blanket the Coastal Communities Surrounding the Gulf of Maine
The passing of the Autumnal Equinox marks the onset of rapid transitions and taxing weather extremes for the wide open plains of the Rumney Marshes ACEC. Socked in by the weather, waves of passerines extend their stay to glean insects and waxy fruits in the dense foliage. Not without peril, the bullys with long tails and wings thrust forward, race through openings to snatch songbirds from the branches of the shrublands in the Bear Creek Wildlife Sanctuary.
 September 17, 2017 TRIP REPORT
Bear Creek Wildlife Sanctuary
Saugus, Essex County, Massachusetts, US

September 17, 2017
9:03 AM - 12:23 PM

Protocol: Traveling

2.0 Mile(s)

43 Bird Species
Canada Goose 20

Mallard 2

Double-crested Cormorant 70

Great Blue Heron 13

Great Egret 4

Snowy Egret 36

Osprey 1

Sharp-shinned Hawk 1

Cooper's Hawk 1

Black-bellied Plover 5

Semipalmated Plover 1

Killdeer 2

Herring Gull 72

Great Black-backed Gull 1

Mourning Dove 4

Ruby-throated Hummingbird 1

Downy Woodpecker 2

Northern Flicker 2

Peregrine Falcon 1

Eastern Phoebe 1

Warbling Vireo 1

Philadelphia/Warbling Vireo 1

Blue Jay 3

American Crow 7

Tree Swallow 1

Black-capped Chickadee 5

House Wren 1

American Robin 10

Gray Catbird 10

Northern Mockingbird 4

European Starling 300

Cedar Waxwing 30

Nashville Warbler 1

Common Yellowthroat 2

Yellow Warbler 1

Wilson's Warbler 2

Savannah Sparrow 40

Song Sparrow 8

Yellow-breasted Chat 1

Dickcissel 2

Bobolink 1

House Finch 5

House/Purple Finch 1

American Goldfinch 35

House Sparrow 4
The Yellow-breasted Chat
The Bird of the Week this week is the Yellow-breasted Chat that was spotted by Ted lurking in the shrubbery. This is the first time this species has been recorded in the sanctuary. What a sharp dresser. Many thanks to Ted and Cammy for these beautiful pictures. Those piercing eyes and that menacing scowl are the last things those poor insects see.

Runner-up this week goes to the Philadelphia Vireo, the Wilson's Warbler, and the Dickcissel. All three of these species are also first time visitors to the sanctuary, that were spotted gleaning for insects in the shrubs with the Yellow-breasted Chat. 

The last few seasons have been exceptional. So far in 2017, we have added 10 new species to our eBirded list. Six of the 10 have been shrubland species that were refueling before continuing on their way.
Scanning Through the Shrublands
Sandwiched between two expanses of tall grass, is a purposefully winding territory between the grassland and the marshland. The shrublands of the sanctuary wrap around the landform like a braid of rope that ties three ecosystems together. 

During migration periods, the wooded edge abutting the grassland is one of the most universally utilized ecotones for migrating songbirds. An area where both woodland and grassland species can find opportunities that suit their needs.

The shrublands are vital migratory habitats that are rich in insects and persistent fruiting shrubs. Shrublands can be utilized by any woodland species during the migration season, and in the off season, they support a diverse group of summer residents.  

For the marshlands, the wooded edge’s role is much more complex. This diverse mixture of short trees and shrubs form the upper zones of the 2.5 mile living shoreline that surrounds the sanctuary. The shrubs stabilize the soils, shade the area with a dense canopy, and most importantly, provide a barrier against many of the invasive species that are commonly found on the shores of urban watersheds.
Unlike a grassland, that can go from seed to feed in a single season, bringing the shrublands to maturity, when they are capable of sustaining a large insect population and producing large volumes of fruits and berries, takes more than a decade. 

Along the way, some of our greatest challenges, have been our greatest assets for establishing one of the largest migratory staging areas on the North Shore. 

In 1998, the perimeter of the 1950’s era landfill, the area that has become the living shoreline of the sanctuary, was essentially decomposed municipal household waste that was placed in the salt marsh from the 1950's-1970's. The only vegetation growing in the area was Phragmites australis , an invasive hybridized strain of reed, originating from the cross pollination of a native reed and an Eurasian variety.
The first order of business was to control the Phragmites, and create suitable growing conditions for our living shoreline. For that, we reached out into the salt marsh and excavated the edge of the Phragmites back 25-30 feet into the household waste. 

The entire area was then covered with 18 inches of Boston Blue Clay and compacted to suffocate the remaining Phragmites roots and rhizomes.
For topsoil, the sanctuary used recycled leaf and yard waste from the Saugus curbside pickup program. The brown paper bags of leaves were composted and used as the organic base soil for all of our soil mixes. For each different ecosystem, varying quantities of sand and gravel was mixed into the organic base soil to develop the right soil characteristics of each plant community.
The grassland and the marshland areas received a 12 inch layer of fine sandy loam. These areas were then immediately planted with a number of seed mixes, including a conservation seed mix, a native wildflower seed mix and bare root native grass seedlings.

The shrubland areas received an 18-24 inch layer of coarser heavier soils, that would conserve soil moisture. On top of the soil layer, an additional 6-10 inch layer of leaf mulch was added to give the soil microbes a jump start. After a brief period to allow the new soil to compact, the entire area was planted with a diversity of bare root woody seedlings.

The sanctuary staff dusted their clothes off and wiped their hands together, saying, 'Well, that's that.'

Jeepers, were we wrong... because... then came the plagues.
The Invasives

The first challenge that befell the shrublands came as a result of the sanctuary's location in the lower regions of a 2,274 acre urban estuary. Our single greatest asset for developing migratory bird habitats, also happens to place the sanctuary in a location where it receives an endless supply of Phragmites seeds that are carried in by the wind each fall. Naturally, many of these seeds germinate, and by season three, it was very clear that without an adaptive management plan, the fast growing Phragmites seedlings would out compete the slower growing woody seedlings.

This led to the development of the Passerine Forage Management Plan (PFMP), aka increased songbird food production. The PFMP focuses on intentionally creating overcrowded growing conditions that force the woody seedling to grow straight and tall as quickly as possible.
The annual activities of the PFMP include overseeding the planting beds with a hand harvested seed mixture that contains the most common wildflower species that songbirds feed on. As it turns out, the most preferred wildflower species are not the big and showy flower garden varieties, although we did include a few of them. Songbird research shows that migratory songbirds actually prefer the tough-as-nails workhorse varieties of wildflowers that most gardeners think of as weeds. Our list contains mainly locally sourced species of Goldenrods, Asters, Ragweed, Queen Anne’s Lace, and Smartweed. 

During the course of the growing season, we cut back the wildflowers and the Phragmites approximately 2-3 weeks after the competing species grow taller than the woody seedlings. This overgrowth and cutback cycle is vital, as it keeps the woody seedling reaching for the sunlight. 

When the seedlings are small, it seems like these day-lighting operations are never ending. But soon enough, the seedlings grow taller, and the need for day-lighting lessens with each passing season. In most locations, the use of the PFMP accelerates the developing canopy of the woody seedlings to out compete the Phragmites in 6-8 years. Complete closure of the canopy can typically occur in approximately 10 years.
The Creepy Crawlers

The second challenge that the shrublands needed to adapt and overcome came as a result of trying to establish woody habitats in an isolated location where woody habitats had never existed before. 

In season four, Eastern Tent Caterpillars (ETC) found their way to our island home for the first time. Within the two seasons that followed, the ETC population expanded to the extent that they were impacting approximately 80% of our woody seedlings.
Lots of people had lots of opinions. But, after reviewing all the facts, including the life cycle of the ETC. All of the sanctuary managers came to the same conclusion. There would be no need for the use of a pesticide. The caterpillars, just like the woody habitats they were occupying, were new to this area, and given a little more time, the parasitic wasps that typically control the ETC, would surely follow.

Instead, the sanctuary focused on developing conditions more favorable for the types of parasitic wasps that would naturally control the ETC. Over the next five seasons, the wasps moved in, and the ETC and the parasitic wasp population was balanced. To this day, the population remains in balance with less than 10% of the woody plants being affected each spring.
The Varmints

The most recent, and most drastic management adaptations were due to the combined effects of the Passerine Forage Management Plan and the expansion of the local Coyote population into the Sanctuary. 

Sometime around 2010, Coyotes became a daily visitor in the sanctuary. As the Coyote visits became more frequent, their presence in the sanctuary pushed out the two breeding pairs of Red Foxes that shared the sanctuary. 

In the few seasons that followed, there was a noticeable increase in the number of shrubs that had died over the winter. The sanctuary had a modest woody seedling replacement budget for matters such as these, and in May, when everything greened up, it didn’t seem like much of a management issue. 

Until, That Season … the one that as the snow melted away, more than six acres of shrubs had just vanished.

When the Cat's away... the mice will play. It all seems pretty clear now, in hindsight, but at the time, nobody saw it coming. When the Coyotes pushed out the Red Foxes, the Pine Vole and Eastern Cottontail Rabbit populations dramatically increased in the densely vegetated shrublands. 

During the summer, the voles and the rabbits would munch away on the lush wildflowers, and in the winter, they would gnaw off the bark and kill the woody seedlings. All while staying out of the reach of the large bodied Coyotes.

Because we are located as an island in the lower reaches of a large estuary, out migration of the expanding vole and rabbit population was difficult, and the two species reached the potential carrying capacity within a handful of growing seasons.
In order to avoid an utter catastrophe over the upcoming season, the sanctuary managers started to review all of the management plans in a focused attempt to adapt to this new challenge before the approaching winter season. 

The results of the review uncovered that a few simple improvements to the Passerine Forage Management Plan (PFMP) should take care of everything. The plan, is still a work in progress, but, so far so good. 

The following efforts are the most favorable adaptations to date. They allow the sanctuary to maintain a healthy varmint population, along with a more resilient shrubland that is better able to adapt to fluctuating seasonal impacts.

Late Fall Vegetation Cutbacks
The most successful adaptation to the PFMP is conducting a late fall cutback of the competing vegetation in portions of the shrublands. 

Each season, after the wildflowers have set seed, the competing vegetation is trimmed with a hedge trimmer at an approximate height of 6-8 inches off the ground. The use of a hedge trimmer is very important. The clean cut, low on the stem, allows the seed heads to stay intact and remain elevated on top of the 6-8 inches of stubble that remains. This allows the seeds to still be available for migrating songbirds. By cutting back the vegetation, larger bodied predators can then gain access to the rabbits and voles. The natural predation of the Pine Vole and the Eastern Cottontail Rabbit population in the shrublands has balanced the varmint population for the last five seasons.
Seedling Protection Tubes
In an attempt to reduce the number of young seedlings that are impacted by the rabbits, all of the new seedlings planted each fall are protected by an 18 inch mesh seedling tube. 

We also protect between 500-1000 naturally generated seedlings in the older established shrubland areas. The efforts of revisiting the established areas, and protecting the seedlings in these areas, ensures that there will always be a stable source of seedlings available if any of the mature shrubs are impacted. 

Expansion of the Shubland Areas
The final step in the adaptation plan is to increase the amount of shrubland habitats available at the sanctuary. 

It may seem a little counterintuitive to provide more winter habitat seemingly so the population can grow larger. But that's not the case. All three steps work hand in hand. The first two steps control the population and increase seedling survival. The final step of expanding the total amount of winter habitat available creates a buffer that allows the shrublands as a whole to become more resilient in the event of a future sudden population increase. It lengthens the amount of time available for the predators to control the population before all the shrublands are impacted.

Over the next decade, our current management plan includes increasing the shrublands by 33% to ensure the resiliency of these important and valuable habitats.
Interestingly enough, we have noticed what appears to be a natural self-preservation response in the older established shrubs.

Gray Dogwood, Silky Dogwood, Chokecherries, and Bayberry are sometimes grouped collectively with a suite of species known as layering, suckering, or mounding plants. This description refers to the plant's tendency to sprout shoots from the root system. Many of these species commonly uses this method to expand the size of the original plant.

Shortly after the rabbit population expanded, we noticed that some of the older established shrubs, especially the Gray Dogwood, sometimes had an interesting pattern of shoots. Each season, many of the dogwoods would produce hundreds of 6-8 inch flimsy shoots throughout the interior and perimeter of the plant. At the same time, these same plants would also produce a typical number of stout 12-18 inch shoots around the perimeter of the plant. 

In the following spring, all of the flimsy shoots will have been eaten by the rabbits, while the main stems, and most of the stout shoots remained intact.

Do layering shrubs sprout sacrificial shoots in response to winter predation by varmint species? What are the advantages of evolving a symbiotic relationship with varmints, rather than evolving a noxious sap or a coarse thick bark? Does the presence of varmints within the perimeter of the plants increase the available nutrients because of the varmint droppings? 

Some mysteries are better left unsolved. 
 The Next Scheduled Nature Walk is:
Sunday, October 1 at 9 a.m. 

NOTE: The Bear Creek Wildlife Sanctuary is open to the public for guided tours only. If you would like to visit the sanctuary, please attend one of our regularly scheduled nature walks, or contact us to arrange a private tour. Thank you.

Special thanks to Soheil, Patricia, Patrick, Ted, Deb, Fred, Kathleen, Cammy, and everyone else who contributed pictures and support this week. Without your help, this publication could not be produced.

Additional pictures from this week:
The Wheelabrator Saugus Bear Creek Wildlife Sanctuary is a 370-acre property abutting a 2,274-acre estuary on the outskirts of Boston, located in the heart of the Rumney Marshes ACEC. Maintained and managed grasslands, salt marshes, shrublands and maturing woodlands combine as one of the largest bird migration staging areas on the North Shore and a habitat for nearly 200 bird species, as well as other wildlife such as coyotes, foxes, raccoons and snakes. Visitors can enjoy the more than 14,000 feet of walking trails that permeate the site, a half-acre exhibit garden, and meeting and lecture areas, which are scattered throughout nine of the restored ecosystems. Situated directly behind Wheelabrator Saugus, the Bear Creek Wildlife Sanctuary is maintained and managed by Geoff Wilson of Northeast Wetland Restoration. Follow along with us as the birds change with each passing season! 
Issue 2017-01 The Short-eared Owl
Issue 2017-02 The American Kestrel
Issue 2017-03 The Peregrine Falcon
Issue 2017-04 The Smith's Longspur
Issue 2017-07 The Horned Lark
Issue 2017-08 The Savannah Sparrow
Issue 2017-09 The Upland Sandpiper
Issue 2017-10 The Killdeer
Issue 2017-12 The Annual Breeding Bird Survey
Issue 2017-13 Salt Marshes / Sea Level Rise
Issue 2017-14 The Common Green Darner
Issue 2017-15 Birds of Prey