February 2019

Front Cover: February 2019

Sat, 23 Feb 2019 12:35:58 GMT

Iceland Gull

The Iceland Gull (Larus glaucoides) is one of the world's most interesting and enigmatic gull species because its Arctic homeland makes it difficult to study. The variability in plumage and hybridization among the species' three subspecies makes identifying an individual to the subspecific level problematic. The nominate population of the Iceland Gull (L. g. glaucoides) is a "white-winged" gull that is smaller than a Herring Gull (L. argentatus). Most individuals of the race glaucoides lack gray on the wingtips. Adults have a light gray mantle and upper wing surface; immatures tend to be creamy brown as juveniles that turn whiter by their second year. The Kumlien's subspecies (L. g. kumlieni) is similar in all plumages, but has a highly variable amount of gray in the primary feathers, producing wing tips that vary from practically all white to dark gray, often making it hard to separate some of them from the Thayer's subspecies (L. g. thayeri), which has blackish wing tips. All subspecies have yellow bills with a red spot on the lower mandible and pink legs. Immatures have black bills.

Iceland Gull taxonomy has a long and confusing history. The Kumlien's Gull has, at one time or another, been considered a full species, and a subspecies of both Thayer's Gull and Iceland Gull. The Thayer's Gull also has been considered a full species, as well as a subspecies of both Herring Gull and Iceland Gull. In 2017, based upon twenty-first-century studies the American Ornithological Society lumped the Thayer's Gull with the Iceland and Kumlien's gulls to form a single species that retains the name Iceland Gull for all of the three races/species. How's that for confusing?

All three subspecies breed in coastal colonies in the Canadian Arctic Archipelago. The nominate Iceland subspecies breeds in eastern and southwestern Greenland. The Kumlien's subspecies breeds on the eastern half of Baffin Island. These two subspecies mainly winter in the North Atlantic, mostly in coastal southern Greenland and Iceland for glaucoides, and in eastern Canada and the northeastern United States for kumlieni, with a few wandering south along the United States coast to Virginia, and inland along the St. Lawrence waterway to the eastern Great Lakes. The Thayer's subspecies breeds in Buchanan Bay and the Arctic Islands of Nunavut, Canada, and winters along the west coast of Canada and the United States south to Baja California. In Massachusetts, wintering Iceland Gulls are considered uncommon to locally fairly common, with immature birds predominating. The Thayer's subspecies is considered a rare winter visitor.

The vocal array of Iceland Gulls is similar to that of the Herring Gull. A high-pitched laughing call signals dominance and may reflect a bird's place in the social hierarchy. They also utter a choking call at or near the nest, and barking calls before or during flight.

Iceland Gulls are presumed to be monogamous but little is known about courtship and pair formation. It is thought that they do not breed until after their fourth year but data are lacking. Little is known about territoriality or nest placement on densely packed cliff-face colonial nesting sites. Iceland Gulls often share nesting cliffs with Black Guillemots, other alcids, and Black-legged Kittiwakes. The nest selection process is unstudied. The nest material usually consists of loose, coarse vegetation and moss, often lined with feathers. The usual two to three eggs, laid in May or June, are gray or grayish-brown splotched with a variety of colors. Little is known about the nesting cycle, but both parents apparently develop brood patches and share incubation for the 24–26 days until hatching. The chicks are semiprecocial; they are covered with down and their eyes open soon after hatching. It is thought that the fledging period is 4–6 weeks. Little is known about the parents' role in feeding the chicks. In the fall, the independent young wander widely to the north or south. Whether Iceland Gulls are breeding-site faithful is unknown.

Iceland Gulls are opportunistic foragers. They are mainly surface feeders, and may take food in flight or while sitting on the water. They also regularly follow fishing boats. Their diet includes mainly fish, but they also take carrion, marine insects, other marine life, and the eggs of other birds. In winter they sometimes forage at garbage dumps with other gulls.

At breeding colonies, Gyrfalcons and Peregrine Falcons may prey on both adults and young Iceland Gulls, as may Glaucous Gulls, Common Ravens, and Arctic foxes. Historically, Iceland Gulls were harvested for their feathers and are still hunted for food by Inuits. Human impact is sometimes significant, particularly at breeding colonies, where the use of modern firearms, unenforced catch limits, and motorboats approaching nesting colonies may cause disruption. Oil spills have also been known to have a negative impact on Iceland Gulls. Despite these factors, the Iceland Gull is not considered threatened or endangered. Inaccessibility of many of the Arctic breeding colonies offers the Iceland Gull its best protection.

William E. Davis, Jr.

Birding Sharon, Massachusetts

Fri, 01 Feb 2019 00:00:00 GMT

The Moose Hill complex

There are two conservation properties on Moose Hill, owned by separate organizations; they are contiguous and share a couple of trails. Mass Audubon's Moose Hill Wildlife Sanctuary is the organization's oldest sanctuary and encompasses 1,971 acres of forest, wetlands, and fields. The sanctuary's Farm at Moose Hill is a Community Supported Agriculture Program (CSA) in partnership with Ward's Berry Farm; the CSA farm fields are near the Ward's Farm fields. A good map of Mass Audubon's Moose Hill Wildlife Sanctuary can be found here: https://www.massaudubon.org/content/download/8080/145429/file/moosehill_trails_2015.pdf

Moose Hill Farm, a 347-acre property owned by The Trustees of Reservations, is a former "gentleman's farm" located on the north side of Moose Hill along Moose Hill Street, with trails through forest and open fields. Instead of crop farming, the Trustees have started a meat CSA, raising and pasturing beef cattle in their fields. A map of The Trustees' Moose Hill Farm can be found here: http://www.thetrustees.org/assets/documents/places-to-visit/trailmaps/Moose-Hill-Farm-Trail-Map.pdf

Mid-winter to early spring

If it has been a snowy winter (it seems to me that Sharon gets more snow than most of southeastern Massachusetts) and Lake Massapoag is frozen, it can be tough birding in mid to late winter. If Lake Massapoag stays open, the geese flocks usually stick around and are always worth a check—Brant, Snow, Ross's, Greater White-fronted, Barnacle, and Cackling geese all have been seen in the last ten years. The best places to check for geese flocks are the Ward's fields and the adjacent Wolomolopoag Pond, the Moose Hill Wildlife Sanctuary's CSA fields, and Lake Massapoag (see map). If there is some open ground, these fields can host flocks of Horned Larks, with the occasional American Pipit, Snow Bunting, or Lapland Longspur. American Tree Sparrows are uncommon locally but can be found along the brushy edges of these fields. They seem partial to the power line cut that runs from Furnace Street to Pine Street and along Gavin's Pond and Wolomolopoag Pond (best accessed from either Furnace Street or South Main Street).

As March comes around, duck numbers start to increase. Leach Pond at Borderland State Park, which is in both Sharon and Easton, can have good numbers of Ring-necked Ducks and Common Goldeneyes; it is the best spot around for whatever dabbling ducks might be in the area. There is usually a raft of Common Mergansers on Lake Massapoag; sometimes they are at the nearby, much smaller Mann's Pond on Billings Street where you can get much better views. Massapoag is good for a variety of ducks that use the lake during the day, but the real draw for Massapoag is the dusk roost. There are a gull roost and a duck roost at Massapoag. The spring duck roost peaks in March, with Common Goldeneye (high of 85), Ring-necked Duck (185), Hooded Merganser (155), and Common Merganser (210) all peaking the second week of March. Bufflehead (70) has a less distinct peak during the last two weeks of March into the first week of April. This type of birding is not for everyone, but it can be rewarding. Patience and a large objective spotting scope are musts—as is a good sense of duck shapes.

It is nearly impossible to predict when it is going to be a good night for gulls at the roost, and numbers can fluctuate greatly from one night to the next. There also is no apparent pattern of when unusual gulls show up in the mix. Lesser Black-backed Gulls, especially, seem to appear for a night or two only to go missing and then reappear a couple nights later. The gulls (unsurprisingly) like to roost in the middle of the lake. This makes viewing them difficult and a spotting scope necessary. Depending on the wind direction, the gulls may be closer to either the south or north end, whichever is in the lee of the wind. Both ends of Lake Massapoag have easily accessible public viewing and parking. The parking lots for Memorial Beach on the north side often are not plowed in the winter, but the boat ramp on the north side is usually at least partially plowed. The viewing from the south end is from the community center, and that lot is always plowed. You can't view the roost from the parking lot there, but it is a short walk of 200 feet across a lawn that is usually windswept but may have some high snow drifts on occasion. The gull roost is predominantly Ring-billed Gulls and varying numbers of Herring Gulls. Great Black-backed Gulls are usually present in small numbers. Iceland, Glaucous, and Lesser Black-backed gulls are uncommon to rare.

Rusty Blackbirds typically can be found in late February through March along the mile-long Beaver Brook Trail that runs between Farnham Road and the Sharon commuter rail station. The Rustys are usually found in a spot that is closer to the Farnham Road entrance. Park outside the yellow gate on Farnham Road. Walk in past the gate and follow the road to the Beaver Brook trailhead, which is on the right side of the road beyond the stump dump, yard waste, and composting facility area. If you reach the pump house you have gone too far. Your best chance of having Rustys is along the first 0.2 mile of the trail into the woods. Listen for them calling or singing, and check for them perched on the tops of cedar trees in the swamp. Most of the trail is close to the brook. From the center of town, you can access the trail by driving to the south end of the outbound parking lot for the commuter rail and following the signs for the Beaver Brook Trail down the dirt road off the parking lot.

Starting in March, the large pasture field at The Trustees' Moose Hill Farm is a favored display ground for American Woodcocks. They also use the nearby power line cut that runs through Moose Hill and the old Poor Farm area of the Moose Hill Wildlife Sanctuary. You can easily access the power line from Moose Hill Street. Counts of five to ten are not uncommon depending on how much of the area you cover.

Spring Migration

Spring migration can be hit or miss locally. Sharon has so much good habitat that there isn't one good migrant trap to concentrate the birds. That said, we do have good spring mornings in town. Throughout May, there are guided walks of the Billings Farm Loop at Moose Hill Wildlife Sanctuary before work, usually starting at 6:00 on Tuesdays and Thursday mornings; check the South Shore Bird Club and Mass Audubon websites to confirm times and dates. This loop passes through varied habitats and has produced some rare birds including Olive-sided and Yellow-bellied flycatchers, Clay-colored Sparrow, and Mourning, Hooded, and Kentucky warblers. Louisiana Waterthrushes are uncommon around the Moose Hill complex where they show up in red maple swamps rather than near rushing water. No one trail is noticeably better than the others for getting good numbers and diversity of migrants, so pick a trail that suits your interests. Some of the more intriguing trails at the Moose Hill sanctuary are the Bluff Trail, the Kettle Trail, and the Pepperbush Trail; all will lead you through a range of habitats and often near streams, swamps, or other wet areas.

Worm-eating Warbler. All photographs by the author.

Breeding Season

One of highlights of the breeding season is the number of Worm-eating Warblers that breed at Moose Hill. They have expanded in the last five to ten years, going from only a few pairs to close to 30 pairs. They can now be found on most trails at Moose Hill, but the highest densities are along the Summit Trail, the Bluff Trail, and the Kettle Trail/Ovenbird Trail area, which is the original hotspot for this species. On the Trustees' property, the best trail for Worm-eating Warblers is the Woodland Trail. For the past couple of years, one pair has been relatively easy to get as a drive-by from Moose Hill Street just south of the power line crossing. I have not explored much of Borderland State Park, where there seems to be only a small population.

Moose Hill has one of the larger areas of undisturbed forest in Sharon, where numerous woodland birds breed. At least two pairs of Pileated Woodpeckers can be found, along with other forest birds such as Hermit and Wood thrushes, Brown Creeper, Eastern Wood-Pewee, Scarlet Tanager, Black-billed and Yellow-billed cuckoos, and Broad-winged Hawks. Blue-gray Gnatcatchers and Veerys are easily found in any of the red maple swamps in town, and Tree Swallows and Eastern Bluebirds nest in boxes in most of the fields.

The two main power line cuts in Sharon, the one that cuts through Moose Hill, and the one that goes from Furnace Street to Pine Street, have good populations of breeding shrubland birds such as Blue-winged and Prairie warblers, Field Sparrows, Eastern Towhees, and Indigo Buntings. Barred Owls are common nesters, and it is not uncommon to come across a family when walking one of the trails in late May. Eleven species of warbler breed in town with some regularity, highlighted by Northern Waterthrush, Black-and-white Warbler, American Redstart, and Black-throated Green, which unfortunately is declining rapidly as we lose the hemlocks to the woolly adelgid. Most of these warblers breed at Moose Hill; another good place for breeding warblers is the King Philip trails on town conservation land in the southern end of town. Access these trails from a small parking lot on Mansfield Street at 42.074279, -71.179982 across from 98 Mansfield Street. Yellow-throated Vireos breed around the ponds at Borderland State Park, and probably around the marsh at the Trustees' Moose Hill Farm as well, but that hasn't been confirmed yet. Savannah Sparrows breed in the large pasture field at Moose Hill Farm and also in small numbers in the sanctuary's CSA farm fields. Borderland State Park has not been carefully covered during the breeding season and could hold some interesting surprises.

Fall Migration

Fall migration starts in August with inland shorebirds and early warblers. If there hasn't been too much rain, Leach Pond at Borderland State Park can be great for shorebirds and ducks. It has looked like an absolutely perfect spot for a rare inland Little Blue Heron, and there are records of Glossy Ibis. Least Sandpipers and Killdeer are the most abundant shorebirds to frequent the flats, and there also have been Semipalmated Plovers, Semipalmated Sandpipers, Greater and Lesser yellowlegs, Spotted and Solitary sandpipers, and a single Pectoral Sandpiper. Viewing the shorebirds is difficult, since the only way to view them from Sharon is to bushwhack off the Pond Walk trail, and even then there's not an unobstructed vantage point.

The better viewing spots are from the Pond Walk trail on the Easton side (and therefore in Bristol County). The easiest access is from the trail as it passes along the small cove on the south side of Leach Pond. This cove is often one of the first places with exposed mud, and there is good, close viewing. The other option for viewing is from the woods along the edge of the hay fields around the farmhouse. There are two spots within these woods that offer a decent, if obscured view. One is from the east side of the pond near 42.065982, -71.149284. The woods here are sparse, and it is not difficult to walk through and find a gap in the trees. The other viewing point is near here 42.063603, -71.151607 but sometimes requires standing in some mud for a better view.

These Pond Walk trail vantage points in Easton are typically better than the cove in Sharon for viewing ducks, which tend to be in the middle of the pond. The best option is probably near 42.062971, -71.154341. The ducks arrive a little later than the shorebirds; mid-September to the end of November is the best time period. On a good day, the ducks include Northern Pintail, American Wigeon, Northern Shoveler, and both Green- and Blue-winged teal. This is also a staging pond for Wood Ducks, with high numbers present from mid-August to mid-October, with the peak of over 100 individuals in mid-September. The trails through the woods to these vantage points can be decent for fall warblers, so keep an eye out for movement.

Snow Goose.

As the last week in September rolls around, the focus for land birding turns to weedy areas. The best place for weeds is the Ward's fields off Wolomolopoag Street. The Farm at Moose Hill CSA fields (both upper and lower) have better public access but often get plowed under sooner. The best birding locations may shift from year to year but the general patterns hold true. The upper CSA field is usually the first to get plowed, so it is the first to get American Pipits. The weedy corner on the edge of the lower CSA field is a good spot where sparrows and the occasional warbler perch up.

The Ward's fields are a bit harder to bird but can be rewarding. It is possible to walk the fields, but you must be careful to stay out of the way of the workers and stick to the farm roads and paths. Do not walk through pre-harvest crops. The overgrown squash patches are one of the better places for Connecticut Warbler. The tomato patch and the weedy road edges are usually the best areas for sparrows, but they can be anywhere. Song and Savannah sparrows can be quite abundant in these fields, with smaller numbers of Swamp Sparrows and Bobolinks. Common Yellowthroat, Palm, Blackpoll, and Yellow-rumped warblers are regularly seen feeding in the weedy patches with the sparrows. Indigo Buntings can also be found, along with the occasional Dickcissel. Blue Grosbeaks and Lark Sparrows have been seen in the lower CSA field but not across the street at the Wards fields, probably due to lack of vegetative coverage.

There are two smaller weedy patches in town that are quite hit or miss for grassland birds. The Sharon Community Gardens at the corner of East Foxboro and Gunhouse streets is not usually a good spot, but occasionally it has been productive. The town stump dump, yard waste, and composting facility on Farnham Road (park outside the gate and walk in) is a small but good place for sparrows in the fall. It seems to be better than the other fields for White-crowned Sparrows and especially for Indigo Buntings, with counts of six to eight.

Late fall early winter

Starting the last week of September or the first week of October, gulls and ducks begin to roost at Lake Massapoag again, but the roosts don't have such distinct peaks in the fall as they do in March. Look for Canvasbacks or Redheads in October and November; they are seen sporadically, though probably are decreasing. Sea ducks are more prevalent in the fall than in early spring. Scoters and Long-tailed Ducks are most common from mid-October to mid-November. Buffleheads and Ring-necked Ducks peak the first week of November, and Hooded Mergansers peak around the first of December. Common Mergansers don't peak until mid-December. All three grebes—Red-necked, Horned, and Pied-billed—can be found on the lake from late September through early December.

This is also peak goose season. The goose flock at Ward's fields changes frequently. The best places to see the geese are in the Ward's fields off Wolomolopoag Street, at Wolomolopoag Pond, and at Lake Massapoag. At Lake Massapoag the geese tend to congregate at the cove on the west side, which is difficult to see because it's a far scope from the southeast corner. Sometimes you can see part of the flock from the end of Sturges Road, but you have to look through trees and someone's yard.

Amenities

Support local businesses. Angels Café is located right in the town center and is your typical coffee café. Ward's Berry Farm has a small store and café with a smoothie bar, sandwiches, and homemade zucchini bread. There are also various delis and Chinese and Indian restaurants in Sharon, most in the center of town (Pond Street and South Main Street) or at the Heights Plaza on South Main St just north of the Ward's Fields. For folks who need their Dunkin or Starbucks, both are located, along with a newly renovated Shaw's supermarket, at the Shaw's Plaza on South Main Street near I-95.

Additional information

http://www.sharonfoc.org/ Not always current, but has information on town-related conservation issues and trails. More information on the non-Moose Hill trails can also be found here.

http://southshorebirdclub.wixsite.com/ssbc

https://www.massaudubon.org/get-outdoors/wildlife-sanctuaries/moose-hill

http://www.thetrustees.org/places-to-visit/greater-boston/moose-hill-farm.html

Liam Waters has lived in Sharon for as long as he can remember. His birding interest was started at Moose Hill when he was eight, and Sharon remains one of his favored patches. He has done various bird surveys across the state, including point counts along the Moose Hill power lines and transect surveys of Stellwagen Bank National Marine Sanctuary. He will put his Sharon birding on hold for the next few years while he finishes a Bachelor of Science degree in Wildlife Ecology and Conservation at the University of Massachusetts Amherst, but he is looking forward to finding new patches near Amherst.

Parker River National Wildlife Refuge Banding Station

Fri, 01 Feb 2019 00:00:00 GMT

I approach a net and see movement within. A Gray-cheeked Thrush has flown into the lower part of the net as it traveled through the understory. It flutters fruitlessly as I approach. I assess how tangled the bird is. This one will not be too difficult; between two fingers I carefully grip its legs behind the heels, coax strands of net away from its claws, free the tail feathers, work loops of net away from the shoulders and flight feathers, shift my hold on the bird to a bander's grip around its neck and back that prevents its wings from flapping, and finally slip the net over the bird's head, freeing it. It is vibrantly alive in my hand, fragile yet filled with a tensile strength. I marvel that this small body will fly hundreds of miles this fall. The thrush has kept up a running commentary of protest throughout its extraction from the net but is relatively calm as I place it in a small cloth bag to bring back to the banding station. Once there, the bird will be measured, assessed, and given a metal leg band with a unique identifying number before it is released back into the woods.

The PRNWR banding station, operated by Mass Audubon Joppa Flats with permission by the refuge management, opened in 1998 and has run continuously since then under the guidance of federally licensed bird banders supported by a group of dedicated volunteers. Nets are placed along a set of backwoods paths during the peak migration times of April-May and September-October. The focus is on songbirds, but any bird that flies into a net, like the occasional Sharp-shinned Hawk, Saw-whet Owl, or even a wayward Northern Harrier, will be banded. The one exception is hummingbirds, which require a special permit and are immediately released if captured. Over the last 21 years, 50,063 individual birds have been banded, representing 126 species. An average of 1,230 individual birds are banded in every spring, and 1,061 every fall. The most frequently banded bird is the Gray Catbird, with 6,445 banded to date. Notable rarities over the years have included Ash-throated Flycatcher, Green-tailed Towhee, and Yellow-green Vireo.

On a local level, the data gathered helps the refuge staff in its habitat management by providing insight into which species are foraging and in what kind of vegetation. On a global level, researchers can use the data collected to conduct migration studies and look at changing patterns in individual species over time. That information can be used to determine the impact of climate change, whether it's an increase in formerly southern species expanding their range or former residents decreasing in number as they shift farther north in response to changing food resources and temperature conditions.

A Red-breasted Nuthatch being released after banding.

I began volunteering at the banding station in the fall of 2015, after taking a training workshop at Joppa Flats in September of that year. Novice volunteers start out by observing the experienced extractors removing birds from nets and recording data as banders process the birds. Although my description of extracting the Gray-cheeked Thrush may have sounded simple, the reality is often a complex tangle of net and wing and thigh and feather and claw, with every species offering its own unique challenge. A Brown Creeper, for example, has almost no upper leg to grasp, and those long toes get caught over and over as you work on the bird. Kinglets of both species will helicopter around in the net, making the challenge of extracting those tiny birds all the more difficult. Northern Cardinals will grab your skin in a vise grip with that strong beak and raise blood blisters, but you must calmly take it as you work to free the bird. Gray Catbirds have little balls at the base of their nails that will catch on net strands, and Eastern Phoebes are susceptible to wing strain if allowed to flap around too much. So it is important to watch, listen, and learn before trying your hand, and it is also important to know when to ask for help, because the birds' safety comes first. The recording of data is also a form of training, as you listen to the banders determine sex, measure body fat, and assess age through feather molt and wear. Although one might be technically proficient at handling birds and be able to affix a band to a bird's leg, you cannot be a bander until you are able to conduct a general assessment of a bird.

One of the real joys of the banding station for me has been getting to know the various birds as individuals of a species. They all have their own personalities and behaviors, and after I have seen them in the nets over time, I get a better sense of who that bird is. From a mechanical standpoint, understanding how a bird's wing or leg works because you have felt it stretched out in your hand gives insight into how different species and body types of birds move through the air and perch on branches. When I see a species in the field, I have a deeper appreciation of why it behaves as it does, from twirling kinglets to cocky chickadees to melodramatic catbirds. I feel more closely connected to the entire environment as I watch birds fulfilling their natures and physical beings, each fitting into their own niche as part of a complex whole.

And then there is the chance to see truly fantastic little birds up close instead of at a distance through binoculars. Spring warblers are expectedly resplendent in their finery, positively glowing in their blues and greens and yellows, but even the "little brown jobs," the sparrows, wrens, and creepers of the bird world, are wondrous mosaics of rich browns, delicate grays, russet reds, and soft buff colors when they are right in front of you. I could hardly believe a Brown Creeper was the same little mousy bird seen up on tree trunks when I first held one in my hand. They are all tiny treasures.

Because the banding station is in an area of the refuge not open to the public, visitors cannot just stop by, but Mass Audubon's Joppa Flats Education Center, PRNWR, and several area bird clubs include regular visits for adults and families to the banding station among their programs. Joppa Flats runs training sessions twice a year for those who think they might be interested in volunteering. The commitment of volunteering is not for everyone, but I highly recommend a visit to your local banding station for all birders. You will see birds in a way that you have never seen them before.

For more information on the banding station, please visit: https://www.massaudubon.org/get-outdoors/wildlife-sanctuaries/joppa-flats/about/bird-banding. Special thanks to Ben Flemer for supplying banding station data.

Regina Harrison is executive assistant and sales coordinator at Mount Auburn Cemetery, a regular volunteer at the PRNWR banding station, and an associate editor of Bird Observer. She is engaged in a long-term habitat restoration project at her home in Woburn, Massachusetts, with an emphasis on providing year-round food and shelter for birds.

Mass Audubon’s Sanctuary Inventory and Monitoring Project

Fri, 01 Feb 2019 00:00:00 GMT

We used point counts, a standard protocol in which observers stand in the middle of a circle and record all birds seen or heard within and outside the circle for ten minutes. The radii of the circles were 50 meters in forests, shrublands, and small fields and 100 meters in open habitats such as large fields and salt marshes. Surveys were carried out three mornings in June, the height of breeding activity in Massachusetts. Multiple circles were set up on each of our larger properties, and each circle contained one type of habitat (e.g., forest, grassland). Having a set size for each circle allows us to compare the species richness (number of species) and abundances for circles of the same habitat type. We currently have over 300 of these counting circles on 48 Mass Audubon properties.

For some of the discussion that follows, we have classified each sanctuary into one of six ecoregions (Figure 1). Ecoregions are large landscape units characterized by a similarity in climate, geology, physiography, and characteristic species assemblages. Because we have fewer results from the western part of the state, we ended up pooling all sanctuaries west of the Connecticut River into a Berkshires/Western MA ecoregion.

As of 2018, we have recorded 149 of the 218 species that are known to breed in Massachusetts during these surveys. The 218 species figure is taken from the results of the last Breeding Bird Atlas (Walsh and Petersen 2013). The 149 species were based on observations made within and beyond the point count circles. This does not mean that all 149 species are breeding on our sanctuaries, but rather that they are likely breeding somewhere in the area of the sanctuary and at a minimum passed through our counting circles during a survey. Some of the species that are missing from our list are birds that are not likely to be recorded by our point count surveys. These include owls, Whip-poor-Wills, and other nocturnal species. Other missing species that our methods did not capture are colonial and beach-nesting water birds, such as wading birds and Piping Plovers. Nonetheless, 25 of the 49 species that are listed as conservation priorities under the State Wildlife Action Plan (SWAP) were recorded in these surveys. Sanctuaries in the Cape Cod and Islands and the Southern New England Coastal Plain and Hills ecoregions, both in the eastern part of the state, had the largest overall numbers of species and SWAP species (Table 1). This could be due to the diversity afforded by coastal locations but they also had more sampling.

Sanctuary	Town	Ecoregion	# Species	# SWAP Species	Years Sampled
Allens Pond	Dartmouth	Bristol Lowlands	91	26	12
Arcadia	Easthampton	Connecticut River	33	5	13
Ashumet Holly	Falmouth	Cape Cod and Islands	46	2	3
Assonet Cedar Swamp	Lakeville	Bristol Lowlands	48	6	3
Attleboro Springs	Attleboro	Bristol Lowlands	54	8	5
Barnstable Great Marsh	Barnstable	Cape Cod and Islands	44	7	2
Boston Nature Center	Boston	Boston Basin	31	3	3
Broad Hill	Holliston	So New England Coastal Plain/Hills	41	6	3
Broad Meadow Brook	Worcester	So New England Coastal Plain/Hills	75	12	9
Broadmoor	Natick	So New England Coastal Plain/Hills	63	8	5
Canoe Meadows	Pittsfield	Berkshires/Western MA	70	8	3
Cedar Pond	Wenham	Boston Basin	48	9	5
Cheshire Pond	Ashburnham	Worcester Plateau	31	6	3
Daniel Webster	Marshfield	So New England Coastal Plain/Hills	61	11	7
Drumlin Farm	Lincoln	So New England Coastal Plain/Hills	73	8	11
Eagle Lake	Holden	Worcester Plateau	44	7	3
Eastern Point	Gloucester	So New England Coastal Plain/Hills	39	6	4
Edgartown Great Pond	Edgartown	Cape Cod and Islands	26	2	3
Elm Hill	Brookfield	Worcester Plateau	55	7	4
Endicott	Wenham	Boston Basin	53	5	14
Felix Neck	Edgartown	Cape Cod and Islands	39	6	3
Flat Rock	Fitchburg	So New England Coastal Plain/Hills	51	11	3
Graves Farm	Williamsburg	Berkshires/Western MA	33	5	13
Great Neck	Wareham	Cape Cod and Islands	61	10	3
Habitat	Belmont	Boston Basin	61	8	12
High Ledges	Shelburne	Berkshires/Western MA	48	7	3
Ipswich River	Topsfield	So New England Coastal Plain/Hills	77	15	6
Lake Wampanoag	Gardner	Worcester Plateau	59	9	3
Laughing Brook	Hampden	Berkshires/Western MA	44	5	3
Lime Kiln Farm	Sheffield	Berkshires/Western MA	56	6	3
Long Pasture	Barnstable	Cape Cod and Islands	49	11	3
Marblehead Neck	Marblehead	Boston Basin	53	9	15
Moose Hill	Sharon	So New England Coastal Plain/Hills	72	11	9
Museum of American Bird Art	Canton	So New England Coastal Plain/Hills	33	2	4
Nahant Thicket	Nahant	Boston Basin	17	1	1
Nashoba Brook	Westford	So New England Coastal Plain/Hills	30	4	3
Norman's Woe	Gloucester	So New England Coastal Plain/Hills	10	0	1
North Hill Marsh	Duxbury	So New England Coastal Plain/Hills	45	4	3
North River	Marshfield	So New England Coastal Plain/Hills	31	3	3
Oak Knoll	Attleboro	Bristol Lowlands	49	6	3
Pleasant Valley	Lenox	Berkshires/Western MA	61	8	3
Roads End	Worthington	Berkshires/Western MA	43	5	3
Rough Meadows	Rowley	So New England Coastal Plain/Hills	82	20	15
Rutland Brook	Petersham	Worcester Plateau	53	7	3
Skunknett River	Barnstable	Cape Cod and Islands	34	2	4
Stony Brook	Norfolk	Bristol Lowlands	62	7	7
Stump Brook	Halifax	Bristol Lowlands	51	4	4
Wachusett Meadow	Princeton	Worcester Plateau	58	11	3
Waseeka	Hopkinton	So New England Coastal Plain/Hills	42	3	5
Wellfleet Bay	Wellfleet	Cape Cod and Islands	59	14	15
West Mountain	Plainfield	Berkshires/Western MA	38	4	3
Whetstone Woods	Wendell	Worcester Plateau	60	9	3

Table 1. Mass Audubon wildlife sanctuaries surveyed during this project, the number of all species, the number of SWAP species recorded, and the number of years sampled during breeding bird surveys. Arcadia and Graves Farms lists based on spot mapping done from 2004–2016 by D. McLain. All other lists were derived from point counts.

Forest Birds

A closer look allows us to compare which birds breed most frequently at different sanctuaries, different ecoregions of the Commonwealth, and different habitats. We had the most data for forest habitat, with 236 circles on 47 properties in forested habitats in all ecoregions. We pooled the sanctuaries into their ecoregions and calculated the percentage of observations in each ecoregion where each species of birds was encountered (Table 2).

Species	All regions	Berkshires Western MA	Worcester Plateau	Southern New England Plain and Hills	Boston Basin	Bristol Lowlands	Cape Cod and Islands
Ovenbird	44%	74%	69%	40%	13%	48%	19%
BC Chickadee	42%	43%	39%	36%	51%	33%	50%
RE Vireo	26%	74%	43%	15%	12%	12%	1%
Tufted Titmouse	25%	15%	17%	0%	47%	40%	32%
Blue Jay	22%	23%	16%	24%	33%	13%	22%
Am Robin	22%	15%	3%	19%	63%	12%	18%
Pine Warbler	20%	3%	6%	25%	26%	19%	39%
E. Wood Pewee	18%	25%	21%	21%	16%	15%	9%
Gray Catbird	17%	4%	1%	13%	35%	21%	30%
White B Nuthatch	16%	11%	7%	25%	18%	22%	12%
D Woodpecker	15%	10%	6%	14%	20%	27%	17%
Am Goldfinch	15%	9%	6%	15%	21%	12%	30%
Scarlet Tanager	14%	24%	26%	16%	6%	14%	0%
Common Grackle	12%	0%	2%	7%	46%	5%	15%
Veery	12%	32%	17%	8%	0%	16%	0%
Wood Thrush	11%	25%	2%	8%	17%	13%	0%
N Cardinal	10%	1%	0%	12%	27%	8%	13%
GC Flycatcher	10%	4%	7%	11%	20%	8%	11%
BH Cowbird	9%	16%	4%	9%	7%	12%	10%
BT Green Warbler	9%	29%	23%	1%	0%	3%	0%
E Towhee	8%	0%	1%	11%	3%	8%	28%

Table 2. Frequency of occurrence in forested habitats of the 21 most common bird species on Mass Audubon properties. Species are listed in descending order of frequency across the entire state.

Across the state, Ovenbirds and Black-capped Chickadees were the most frequently encountered species (Table 2, All Regions column). Well known to all birder is that certain species are more likely to be found in forests in the western part of the state, others in the eastern part, and still others occur everywhere. Our results bear this out (Table 2). Ovenbirds, Red-eyed Vireos, Scarlet Tanagers, and Black-throated Green Warblers were most frequently encountered in the forests of the ecoregions in the central and western parts of the state, whereas Pine Warblers, Gray Catbirds, and Eastern Towhees dominated in the east.

The coefficient of variation (CV) is a measure of how variable a species was among the different ecoregions (Table 3). A low CV means that a bird is encountered at similar rates in the different ecoregions, thus it is relatively evenly distributed among the ecoregions. A high CV indicates that the bird varies substantially from one region to another. The results are, for the most part, consistent with what we know about the different species of birds. Black-capped Chickadee had the lowest CV of all the species. This means that our state bird is fairly evenly distributed across all ecoregions, which certainly agrees with everyone's experience of it. Blue Jays and, surprisingly, Eastern Wood Pewees were also relatively evenly distributed across the state. Common Grackles and Black-throated Green Warblers had the highest variation of any of the birds in our list because their occurrences were skewed toward only a few regions—the Boston Basin on the part of Grackles and the sanctuaries in the central and western part of Massachusetts for Black-throated Green Warblers. Red-eyed Vireo was another species more frequently encountered in the western part of the state. In contrast, Eastern Towhees were particularly abundant in the Cape Cod and Islands ecoregion and almost totally absent from the western Massachusetts ecoregions.

Species	CV	Regions most commonly occurring
Common Grackle	141%	Boston Basin
BT Green Warbler	141%	Berkshires/ Western MA, Worcester Plateau
E. Towhee	128%	Cape Cod and Islands
RE Vireo	105%	Berkshires/Western MA, Worcester Plateau
Veery	101%	Berkshire/W MA, Worcester Plat, Bristol Lowlands
Robin	98%	Boston Basin
No. Cardinal	96%	Boston Basin
Wood Thrush	86%	Berkshire/Western MA, Boston Basin
Gray Catbird	79%	Boston Basin, Bristol Lowlands
Scarlet Tanager	71%	Berkshires/ Western MA, Worcester Plateau
T. Titmouse	70%	Boston Basin, Bristol Lowlands, Cape Cod & Islands
Pine Warbler	69%	So NE Coastal Plain, Boston Basin, Cape Cod & Islands
Am. Goldfinch	59%	Cape Cod & Islands
Ovenbird	57%	Everywhere except Boston Basin, Cape Cod & Islands
GC Flycatcher	54%	Boston Basin
Downy Woodpecker	49%	Boston Basin, Bristol Lowlands
BH Cowbird	44%	Berkshires/Western MA
WB Nuthatch	44%	So NE Coastal Plain, Bristol Lowlands
E. Wood Pewee	33%	All over
Blue Jay	31%	All over
BC Chickadee	18%	All over

Table 3. Amount of variation (Coefficient of Variation, CV) among the regions for the forest birds listed in Table 2. A high CV means that the bird's distribution varies greatly across ecoregions of the state; a low CV means that the bird is relatively evenly distributed across the regions. Birds are listed in order from high CV to low CV.

In addition to counting the birds, we also characterized the vegetation in each forest circle. We classified our forested sites into four types based on tree canopy composition determined from field observations: Deciduous (all broad-leaved trees that drop their leaves in the fall), Deciduous-Evergreen (greater than 50% broad-leaved trees), Evergreen-Deciduous (greater than 50% conifer trees), and Evergreen (all conifer trees such as pines, hemlocks, or spruce). Each circle was classified as one forest type. We analyzed the association of forest birds with different forest types. We included 130 forest circles in this analysis.

Deciduous (19 %)	Deciduous-Evergreen (52 %)	Evergreen-Deciduous (18 %)	Evergreen (4 %)
Red-eyed Vireo	Wood Thrush	American Redstart	Black-throated Green Warbler
Scarlet Tanager		Red-breasted Nuthatch	Blackburnian Warbler
			Black and White Warbler

Table 4. Forest birds that showed a strong preference for certain forest types. The numbers in parentheses are the percentage of circles containing that forest type.

Preference was determined by comparing the percentage of birds in each forest type with the availability of those types (percentage of circles having that forest type). If a bird showed no preference, then its percentage occurrence among the four canopy types should be similar to the percentage of forest types available. Red-eyed Vireos and Scarlet Tanagers were present in deciduous canopy more than the availability of that forest type (Table 4). Black-throated Green, Blackburnian, and Black and White warblers showed the strongest affinity for evergreen canopies. Black-throated Blue Warblers were present in Deciduous and Evergreen circles more than in Deciduous-Evergreen and Evergreen-Deciduous forest types. Note that the number of purely evergreen (coniferous) circles was less common than the other types; one rarely finds pure stands of white pines or hemlocks in Massachusetts without at least some broad-leaved trees mixed in.

Salt Marshes

One of the advantages of this study has been an ability to delve into the status and trends of some birds of conservations concern. Salt marsh birds are high on this list. Their vulnerability to ongoing and more severe, future sea level rise was well documented in Mass Audubon's third State of the Birds Report (Walsh and Severson 2017). The Saltmarsh Sparrow has become a poster child for the effects of sea level rise on birds that nest in salt marshes, but it is not the only species that lives in this challenging habitat. Seaside Sparrows, Willets, and Clapper Rails as well as Saltmarsh Sparrows are all listed on the State Wildlife Action Plan.

Species	Allens Pond	Barnstable Great Marsh	Eastern Point	Great Neck	Rough Meadows	Wellfleet Bay
Saltmarsh Sparrow	1.16	0.00	0.00	0.00	0.42	0.34
Seaside Sparrow	0.54	0.00	0.00	0.00	0.00	0.00
Willet	0.87	0.00	0.00	0.00	0.08	0.35
Red-winged Blackbird	0.58	0.70	4.19	0.18	0.30	0.09

Table 5. Abundances of three obligate salt marsh nesting birds (Saltmarsh and Seaside sparrows, Willet, and another common inhabitant of the marshes (Red-winged Blackbird). Numbers are the average numbers of each species per hectare (1 ha= approximately 2.5 acres).

We carried out breeding bird surveys on six sanctuaries that have at least some salt marsh circles (Table 5). Three contained some obligate salt marsh birds and three did not. Two of the three sanctuaries that lacked obligate salt marsh species are likely too small to attract these specialists. The salt marsh at Eastern Point is seven acres (approximately three hectares) and the marsh at Great Neck Wildlife Sanctuary is three acres. On the other hand, Barnstable Great Marsh Wildlife Sanctuary is part of one of the Commonwealth's largest salt marshes, so its lack of any obligate marsh species is surprising. Of the three sanctuaries that did contain obligate salt marsh species, Allens Pond Wildlife Sanctuary in South Dartmouth, had almost three times the density of Saltmarsh Sparrows of the other two sanctuaries, more than twice the Willet concentrations, and was the only sanctuary that had Seaside Sparrows within counting circles. The volunteers who sampled at Allens Pond, were also treated to three records of Clapper Rails, one of a King Rail, and occasional late-lingering migratory shorebirds.

Allens Pond and Rough Meadows Wildlife sanctuaries have benefited from almost yearly surveys by staff and volunteers since 2004. Rough Meadows is part of the Great Marsh ecosystem of northeastern Massachusetts and abuts the Parker River National Wildlife Refuge. Saltmarsh Sparrow numbers at Rough Meadows vary a great deal from year to year but they do not seem to be suffering from the consistent downward trend that is happening in other parts of its range, particularly in Connecticut and the Mid Atlantic states (see results of SHARP project summarized in Walsh and Servison 2017). Nonetheless, with the anticipated continuation of rising sea levels, the future of this obligate salt marsh species is tenuous at Rough Meadows and throughout its range.

Allens Pond Wildlife Sanctuary provided a unique opportunity to study the effect of the temporary loss of salt marsh vegetation on the obligate salt marsh breeding birds, providing perhaps a hint of what might happen with rising sea levels. In 2008, the marsh was inundated for about six months during the breeding season when the inlet that connects the pond to Buzzard's Bay closed. This prevented the pond and its adjacent marshes from draining at low tide, killing much of the native marsh grasses. In the years before the marsh vegetation died off, we had been monitoring the birds and could document how the loss of vegetation affected them. There was a precipitous decline in Saltmarsh and Seaside sparrows and Willets in the years immediately following the event even after the inlet was reopened. The good news is that after about five years, all three species and the salt marsh vegetation recovered to roughly their "pre-flood" numbers.

A. 100 m radius circles—large fields

SPECIES	#/ha
Tree Swallow	1.00
Bobolink	0.60
Red-winged Blackbird	0.57
Starling	0.21
Common Yellowthroat	0.16
American Goldfinch	0.13
Song Sparrow	0.12
Common Grackle	0.11
Eastern Bluebird	0.09
Cedar Waxwing	0.09

B. 50 m radius circles—small fields

SPECIES	#/ha
species	#/ha
Red-winged Blackbird	0.97
Song Sparrow	0.60
American Goldfinch	0.46
Tree Swallow	0.41
Common Grackle	0.39
Common Yellowthroat	0.29
Starling	0.28
Gray Catbird	0.26
Cedar Waxwing	0.26
Bobolink	0.17

Table 6. Abundance per hectare of the 10 most abundant species from grassland habitats recorded in 100 m and 50 m radius breeding bird count circles. 1 ha= approximately 2.5 acres.

Birds of early successional habitats: Grasslands and Shrublands

An unambiguous message in Mass Audubon's first State of the Birds report (Mass Audubon 2011) was that many birds of grasslands and shrublands have declined over at least the past 40 years. Mass Audubon sanctuaries contain a variety of grassland habitats that were included in our Sanctuary Inventory and Monitoring Program; 21 grassland breeding bird census circles that have radii of 100 meters are located on 7 sanctuaries and 19 circles on 11 sanctuaries have 50-meter radii. The latter represent fields that were too small to fit the larger circles. Since many studies have shown that the area of grassland is a key to its ability to support grassland bird species, we have analyzed these two groups separately (Table 6a and b). Because of the smaller number of circles compared to forests, we have not attempted to compare grasslands of different ecoregions.

There clearly is a difference between the larger fields and the smaller fields. Most notably, Bobolinks were three times more dense and Tree Swallows twice as dense in the large fields. These species are targets of management measures, particularly in large fields. In contrast, Red-winged Blackbirds, Common Grackles, and Song Sparrows were roughly twice as dense in the small fields. These species likely benefit from the proximity of shrubland and woodlands that are characteristic of small fields.

Counting most birds in a field presents a particular challenge because they move around more than forest birds during a 10-minute counting period. Tree Swallow numbers were taken from estimates of the numbers that intersected the circle as they flew by in foraging trips during the 10-minute count period. Bobolinks, although not as frequently airborne as the swallows, moved around the circle quite a lot so observers had to use their best judgment of the number of individuals they were counting.

Neither large nor small fields contained a number of grassland species of conservation concern, i.e., Grasshopper Sparrows and Upland Sandpipers. Likely what we call a large field, such as the 250 acres at Daniel Webster Wildlife Sanctuary, is still not large enough to support the greatest diversity of grassland birds. In addition, the vegetation on these fields, which consists primarily of tall pasture grasses, may not be optimal for species like Grasshopper Sparrows. It is surprising that our number of Savannah Sparrows, which is presumably less area-sensitive than other grassland species, was relatively low in both large and small fields.

Species	#/ha
Gray Catbird	1.44
Yellow Warbler	0.90
Song Sparrow	0.85
American Robin	0.77
Black-capped Chickadee	0.64
American Goldfinch	0.59
Common Yellowthroat	0.58
Baltimore Oriole	0.58
Eastern Towhee	0.55
Red-winged Blackbird	0.55

Table 7. The ten most abundant birds in shrubland at Mass Audubon sanctuaries.

We also had eleven circles in shrublands in seven sanctuaries (Table 7). The most common birds were Gray Catbird, Yellow Warbler, and Song Sparrow, all well-known denizens of shrubby habitats. Eastern Towhee, a SWAP species, was ninth most abundant. Sad to say, we did not record a single Brown Thrasher within any of our shrubland circles, although we did get a few in shrubland outside circles.

Species	#/ha
Red-winged Blackbird	4.11
Common Grackle	1.88
Tree Swallow	1.05
Common Yellowthroat	0.84
European Starling	0.75
Gray Catbird	0.70
Song Sparrow	0.67
Yellow Warbler	0.52
Swamp Sparrow	0.43
Baltimore Oriole	0.29

Table 8. The ten most abundant birds observed in freshwater wetlands on Mass Audubon sanctuaries during our breeding bird surveys.

Freshwater Wetlands

Our sanctuaries contain a variety of freshwater wetlands such as shrub swamps, red-maple swamps, cedar swamps, and wet meadows. We set up seventeen wetlands circles on seven sanctuaries. Pooling all the different types of wetlands together, it is clear that Red-winged Blackbirds are by far the most abundant species in our wetlands (Table 8). Grackles, Tree Swallows, and Common Yellowthroats were also common in wetlands. Of the more cryptic freshwater wetland birds, we have a number of records of Soras and one of a Common Moorhen at Ipswich River, and records of Virginia Rails at Canoe Meadows, Broad Meadow Brook, Stony Brook, and Stump Brook.

One of the limitations of our study is that the mere presence of a bird in a habitat during the breeding season does not mean it is actually breeding in that circle or in the immediate surrounding area. Thus, the common occurrence of grackles and starlings in wetlands during our breeding surveys indicates only that they were present in the area. To properly interpret this information we need to combine our observations with what we know about the life history of each species.

SWAP species in terrestrial habitats

Chimney Swift	6
Eastern Towhee	6
Wood Thrush	6
Black-and-white Warbler	5
Black-billed Cuckoo	5
Blue-winged Warbler	5
Scarlet Tanager	5

Table 9. The ten most abundant birds observed in freshwater wetlands on Mass Audubon sanctuaries during our breeding bird surveys.

As mentioned above, species that are listed on the State Wildlife Action Plan are of high conservation concern, as determined by the Massachusetts Division of Fisheries and Wildlife. Wood Thrush and Scarlet Tanager were the SWAP species that occurred on the most Mass Audubon sanctuaries, each occurring in 35 of the 48 sanctuaries in this study. Eastern Towhee was recorded on about two-thirds of the sanctuaries and Black-and-white Warbler on a little over half. On the other hand, Northern Harrier, American Kestrel, Purple Martin, Cerulean Warbler, and Eastern Meadowlark were recorded on only one place, each at a separate sanctuary.

Species	#ecoregions	Ecoregions present	Comments
Ruffed Grouse	2	Southern New England Coastal Plain and Hills, Worcester Plateau
Sharp-shinned Hawk	2	Boston Basin, Worcester Plateau
Northern Parula	2	Boston Basin, Bristol Lowlands
Northern Goshawk	2	Berkshires, Southern New England Coastal Plain and Hills
Northern Bobwhite	2	Cape Cod and Islands, Southern New England Coastal Plain and Hills
Mourning Warbler	2	Boston Basin Bristol Lowlands
Purple Martin	2	Southern New England Coastal Plain and Hills, Bristol Lowlands
Field Sparrow	2	Cape Cod and Islands, Southern New England Coastal Plain and Hills
Eastern Meadowlark	1	Southern New England Coastal Plain and Hills	Occurred one year only at Daniel Webster
Northern Harrier	1	Bristol Lowlands	Only at Allens Pond
Cerulean Warbler	1	Berkshires	Only at High Ledges

Table 10. Rare SWAP species. Bird recorded in only one or two ecoregions during the breeding season.

From an ecoregional perspective, three SWAP species were recorded in all six ecoregions and four occurred in five of the six ecoregions (Table 9). Scarlet Tanagers occurred on all (100%) of the sanctuaries in the Berkshire, Worcester Plateau, and Bristol Lowlands sanctuaries and were well represented in the Southern New England Coastal Plain and Hills (67%). The only ecoregion where this species was not recorded was Cape Cod and Islands. Wood Thrushes were well represented the Berkshires, the Southern New England Coastal Plain and Hills, and the Bristol Lowlands ecoregion but were not recorded on Cape Cod and Islands. On the other hand, three species were recorded from only one ecoregion (Table 10). Just as the presence of a bird in a breeding bird circle does not mean it is actually breeding in the vicinity, its absence does not mean that it is not breeding somewhere on the sanctuary beyond its detectability from a circle.

Future directions

As mentioned above, one of the motivations for these surveys was to get a baseline of current conditions so that we can examine future changes. Everyone who has done bird surveys knows how variable the results can be. Birds fly, which is, of course, great for the birds but challenging for getting consistent results from year to year and even within our three June surveys each year. When we miss a Wood Thrush we heard singing a week ago, does that mean it is no longer present, has temporarily occupied a different part of its territory, or is just being quiet for the 10 minutes of our survey? We need to be able to separate the signal from the noise in order to be able to detect real change. Using a simple statistical procedure and taking into account the variability in detection from survey to survey, we determined that we would need three years of surveys to be able to detect a 75% change in the numbers of Wood Thrushes at all of our sanctuaries. It would take 10 years to detect a 30% change. For Ovenbirds at one of our sanctuaries (Ipswich River), it would take three years to detect a change of 85%, and 10 years to detect a change of 35%. In sum, a commitment to long term monitoring is needed to detect relatively subtle changes in bird populations.

Acknowledgements

The surveys would have been impossible to carry out without the strong support of many Mass Audubon staff, interns, and volunteers. About 140 observers have contributed their observations to these surveys over the past 14 years. Although too many to list individually, their contributions are acknowledged here. A special thanks goes to members of the Young Birders Club who have been instrumental in surveys carried out at Moose Hill, Allens Pond, Attleboro Springs, and Oak Knoll. Another special thanks goes to staff and volunteers who have enthusiastically made continuous, annual records since 2004. Our original goal was to sample for three consecutive years every 10 years, so these particular staff and volunteers have gone way beyond the original plan and provide us with an invaluable long term data set.

References

Mass Audubon. 2011. State of the Birds 2011. Lincoln, Massachusetts: Massachusetts Audubon Society.
Walsh, J.M., and W.R. Petersen. 2013. Massachusetts Breeding Bird Atlas 2. Lincoln, Massachusetts: Massachusetts Audubon, (Published by Scott and Nix).
Walsh, J. M., and M.S.V. Servison, (eds.) 2017. State of the Birds 2017: Massachusetts Birds and Our Changing Climate. Lincoln, Massachusetts: Massachusetts Audubon Society.

Robert Buchsbaum is the Greater Boston/North Shore Regional Conservation Scientist with Mass Audubon. He received his Bachelor of Science degree in Natural Resources from Cornell and his Ph.D. in Marine Ecology from the Boston University Marine Program, where he studied feeding selection by Canada Geese on salt marshes. In over 30 years at Mass Audubon, Buchsbaum has advised sanctuaries on ecological research, management, and education and has provided technical analysis to the organization on a variety of conservation issues. He is also responsible for coordinating Mass Audubon's statewide Sanctuary Inventory and Monitoring Program, of which the breeding bird surveys is a major component.

Volunteer Positions at Bird Observer - Feb 2019

Fri, 01 Feb 2019 00:00:00 GMT

Digital Production Manager to assist with some key online initiatives

publishing the online edition of the bi-monthly journal
production of digital artwork and PDF publications
assistance with site maintenance and online services

Technically adept, detail-minded individuals are welcome. A creative flair for problem solving and persistence against unforeseen obstacles would be a bonus.

Contact Webmaster Eric Swanzey at eric@swanzey.com.

Bird Sightings Compiler for Worcester County

Our long-running Bird Sightings column relies on data from compilers around the state. The compiler for Worcester County would be responsible for sending in reports every two months of species seen in that county for the previous two months. Species are reported in a spreadsheet template and include sightings that are representative of high counts, early/late dates, and anything rare or unusual. The compiler should be familiar with the birds (and birders) of Worcester County, be comfortable with using a spreadsheet, and be able to use eBird.org to query sightings.

Contact Bird Sightings Editor Neil Hayward at neil.hayward@gmail.com.