Forest degradation drives widespread avian habitat and population declines
by Matthew G. Betts et all, 2022 in Nature Ecology & Evolution. The full text is publicly available.

Also View 2022 Bird Study for highlights and Press Reports which include an interview with the lead author.


In many regions of the world, forest management has reduced old forest and simplified forest structure and composition. We hypothesized that such forest degradation has resulted in long-term habitat loss for forest-associated bird species of eastern Canada (130,017 km2) which, in turn, has caused bird-population declines. Despite little change in overall forest cover, we found substantial reductions in old forest as a result of frequent clear-cutting and a broad-scale transformation to intensified forestry. Back-cast species distribution models revealed that breeding habitat loss occurred for 66% of the 54 most common species from 1985 to 2020 and was strongly associated with reduction in old age classes. Using a long-term, independent data-set, we found that habitat amount predicted population size for 94% of species, and habitat loss was associated with popula- tion declines for old-forest species. Forest degradation may therefore be a primary cause of biodiversity decline in managed forest landscapes.

MCFC Webinar: Migratory Birds and Forestry (Videoed webinar)
With Prof. Cindy Staicer, July 14, 2020. A comprehensive view with many references to local scientific studies.

Maine Audubon Links cited by Prof. Staicer:

Forestry for Maine Birds website

Resources for landowners webpage
Woodland Owners Guide to Forestry for Maine Birds (pdf)
The Resources for landowners webpage has lots of other useful resources aimed at woodland owners.

Resources for foresters webpage
The Forestry for Maine Birds: A Guidebook for Foresters Managing Woodlots “With Birds in Mind” (pdf)
Loggers Guide to Forestry for Maine Birds (pdf)
The Resources for foresters webpage also has links to several other documents: one-page ‘fact’ sheets for each of the 20 bird species of conservation concern, forest habitat descriptions, and forester’s guide forms and tables.

North America Has Lost More Than 1 in 4 Birds in Last 50 Years, New Study Says
Jillian Mock for Audubon Magazine September 19, 2019. “For the first time, researchers have estimated the volume of total avian loss in the Western Hemisphere—and it’s not just threatened species that are declining. Many backyard favorites are also losing ground.”

Pileated woodpecker on large snag

SURVIVAL BY DEGREES: 389 Bird Species on the Brink
Wilsey, C, B et al., 2019. Audubon Society. “Climate change is making the global species extinction crisis worse. In North America, 37% of birds are already at a high risk of extinction, and while historically birds are known to respond to climate change by shifting their ranges, climate change is occurring 20 times faster today than it has during any historical period over the past 2 million years.4 The unprecedented pace and magnitude of climate change make it an existential threat to birds, people, and the natural systems we depend on.” Also see: Climate change threatens extinction for most birds, especially in Canada by Bob Weber / The Canadian Press in

An Estimate of Nest Loss in Canada Due to Industrial Forestry Operations
K.A. Hobson et al.,2013. Avian Conservation and Ecology 8(2): 5.
“Annual loss of nests by industrial (nonwoodlot) forest harvesting in Canada was estimated using two avian point-count data sources… Accounting for uncertainty in the proportion of harvest occurring during the breeding season and in avian nesting densities, our estimate ranges from 616 thousand to 2.09 million nests…” Table 4 lists Estimated number of nests destroyed by forestry operations annually by province. Other tables also list stats by provinces. The study was part of a larger study on Quantifying Human-related Bird Mortality in Canada.
View also Environmentalists worried about potential forestry-related nest loss in the Chronicle Herald, Jan 3, 2017.

Breeding Bird Communities in a Hardwood Forest Succession in Nova Scotia Canada
Morgan, K., and B. Freedman. 1985. Canadian Field-Naturalist 100(4): 506-519.
“The response of breeding birds to hardwood forest disturbance and regrowth was examined using a chronosequence of 23 stands aged from 1 to 74 years. The avifauna of young, clearcut stands (12 years old) was distinct in both species and density from mature stands (20 years old). The most important species of young stands were Chestnut-sided Warbler, Common Yellowthroat, Northern Junco, and White-throated Sparrow, while older stands were dominated by Least Flycatcher, Hermit Thrust, Red-eyed Vireo, Northern Parula, Black-throated Green Warbler, American Redstart, and Ovenbird. As clearcut stands developed and began structurally to resemble a forest, especially with the establishment of a tall, relatively dense shrub canopy, species of birds more typically associated with closed stands began to invade. Bird species density, diversity, and richness levelled off in the transitional stage between recent clearcuts and young forests, and at this stage there was a mixture of open and closed canopy species. With further succession, species typical of young stands were eliminated from the avifauna. The overall effects of timber harvesting upon the avifauna of this hardwood forest were not severe, and were of limited duration.”
Olive-sided flycatcherSelected studies of forestry and bird communities in Nova Scotia and New Brunswick
Bill Freedman and Greg Johnson 1999. Society of Canadian Ornithologists Special Publication No. L 1999. “Forestry practices can cause intense disturbances, which result in dramatic changes in the habitats available to support all elements of biodiversity, including birds. Many species of birds require mature and older forests as habitat for breeding, migratory movements, or wintering; some also use habitats occurring during earlier stages of forest succession, including those created through such forestry unities as elearoutting. We summarise results of several
research protects which have examined the effects of various harvesting systems, plantation establishment, and silviculturel herbicide spraying in Nova Scotia and New Brunswick.

Forestry practices and biodiversity, with particular reference to the Maritime Provinces of eastern Canada
Bill Freedman et al., Environmental Reviews, 1994, 2(1): 33-77
Comprehensive, informative; species, community and guilds associated with forests of different ages are described; conservation challenges addressed. Full Paper (PDF)

Guidelines for Managing Canada Warbler Habitat in the Atlantic Northern Forest of Canada
Alana Westwood et al. 2017. for the Boreal Avian Modelling Project. Comprehensive.

Guidelines for Managing Canada Warbler Habitat in the Northeast and Mid-Atlantic Regions
Harding, C., L. Reitsma, and J. D. Lambert. 2017. High Branch Conservation Services, Hartland, VT.

John F. Kearney & Associates Social and Environmental Research
“Based in Beaver River, Yarmouth County, Nova Scotia, John F. Kearney & Associates is committed to the social and ecological health of communities…In recent years the company has specialized in the environmental assessment of the impact of wind energy facilities on birds in Nova Scotia. A number of baseline studies and post-construction monitoring projects have been conducted in this new but rapidly expanding industry. We have sought to set a high standard of sound methods, consistent data collection, and rigorous analysis in order to ensure that environmental assessments protect and conserve bird populations while contributing to the development of an environmentally sustainable wind energy industry. John F. Kearney & Associates is developing and working with cutting edge technology to acoustically monitor the vast number of birds that pass unseen over wind energy facilities during their nocturnal migrations in the spring and autumn. Acoustic monitoring is an important methodology in the emerging field of aeroecology, and the company has initiated a number of research projects on the aerial habitats of migrating birds.” The website provides results of surveys, acoustic recordings, references to literature etc

Forest birds at risk

There are six forest-linked species amongst the SAR birds for Nova Scotia; changes in forest habitat (bolded below)nare concerns for four of the six:

Canada Warbler (Cardellina canadensis) – Endangered (2013)
About 80% of the breeding range of this neotropical migrant is in Canada and significant declines have been continuing for nearly three decades. Although factors affecting declines of Canada Warbler are not well understood, loss of wintering habitat in South America and climate change may be implicated. Canada Warblers utilize wetlands, swamps, bogs and fens in forest habitats for nesting.

Rusty Blackbird (Euphagus carolinus) – Endangered (2013)
Rusty Blackbirds utilize wetlands around lake edges, bogs, swamps and edges of fens for breeding, wintering in the central parts of the United States. Slow, steady long-term declines spanning over three decades have resulted in the listing of this species as Endangered. Factors affecting the decline are unclear, however habitat changes and blackbird control programs in agricultural landscapes in the wintering grounds are believed to be major threats. About 70% of the breeding range of Rusty Blackbirds is in Canada.

Bicknell’s Thrush (Catharus bicknelli) – Endangered (2013)
Bicknell’s Thrush is endangered because of habitat change, low numbers, patchy distribution, and low reproductive potential. However, little is known about this secretive species. It breeds in Quebec, New Brunswick, Nova Scotia and the northeastern United States. In Nova Scotia, it is currently restricted largely to Cape Breton Island, although historically it was found on a few offshore islands in the southwest part of the province. Habitat has been altered in Nova Scotia over the last century by infestations of spruce budworm and forest management practic

Olive-sided Flycatcher (Contopus cooperi) – Threatened (2013)
Olive-sided Flyactcher are one of the most characteristic birds of spruce and fir swamps and bogs with open water in Nova Scotia. The plaintive call can be heard from great distance that many transcribe as `Quick Three Beer!` Long-term declines of 79% across Canada have been punctuated by more recent declines of 29% between 1996-2006. Habitat loss in the wintering grounds, changes in the insect food base and climate change are all factors implicated with the decrease in Olive-sided Flycatchers.

Evening Grosbeak (Coccothraustes vespertinus) – Vulnerable (2017)
The Evening grosbeak is a large chunky social finch with a thick bill, bright distinctive coloration, and noisy call. A flocking bird, it forages in treetops and branches for insects, seeds and berries and is a frequent visitor to winter feeders. It lives in mature mixed and softwood boreal forest. Evening grosbeak has exhibited marked long-term decline throughout most of its range over the past 20 years. The cause of the decline of Evening grosbeak is unknown. Habitat loss in its boreal breeding areas and climate change may be contributing to the long term downward trend.

Eastern Wood Peewee (Contopus virens) – Vulnerable (2013)
Eastern Wood Peewee are one of the most characteristic birds of woodlands in eastern North America, but have suffered ongoing declines over nearly four decades. Feeding almost exclusively on small flying insects, this small flycatcher nests high out on a forked limb finishing its nest with bits of lichen for camouflage. Causes of the declining numbers of Eastern Wood Pewee are unclear, but are thought to be implicated with loss of habitat in the wintering range in South America, forest practices in Canada, climate change and other factors.

Forests succession, deadwood
A couple of lists of birds observed or compiled by the late Bill Freedman and associates illustrate how forest harvesting can have strong effects on bird communities by their effects on successional habitats and dead wood. (Page on this website)

OG Species at Risk
Page on this website adapted from a section in Mosseler et al. 2003. Old-growth forests of the Acadian Forest Region. Environmental Reviews 11: S47–S77 (2003)

Conservation of three forest landbird species at risk: Characterizing and modelling habitat at multiple scales to guide management planning
Alana Westwood, PhD thesis, Dalhousie University 2016. “To effectively conserve species at risk (SAR), it is important to understand their ecology at multiple scales, including stand-level habitat associations and landscape-level distribution. The Rusty Blackbird (Euphagus carolinus), Olive-Sided Flycatcher (Contopus cooperi), and Canada Warbler (Cardellina canadensis) are listed landbird species at risk (SAR) that breed in wet forest habitat in Canada’s Maritimes. To characterize their habitat for stand-scale conservation, I surveyed vegetation cover and structure at 99 known locations in the Southwest Nova Biosphere Reserve…When comparing predicted population sizes to regional population estimates, national parks supported habitat for only 3-4% of Canada Warblers and 1-2% of Olive-sided Flycatchers. Thus it is highly unlikely that existing national parks alone are able to maintain viable regional populations. To help prevent extirpation of these species, forestry prescriptions need to be adjusted to conserve habitat, and key locations for management should be identified at a regional scale.” Also view the ongoing project: Landbird Species at Risk in Forested Wetlands

Bird Conservation Strategy for Bird Conservation Region 14 and Marine Biogeographic Units 11 and 12 in Nova Scotia: Atlantic Northern Forest, Scotian Shelf and Bay of Fundy, and Gulf of St. Lawrence
– Abridged Version – October 2013 Government of Canada
The landscape of Nova Scotia is a combination of mountainous terrain, lowland plains and coastal landforms typical of the Atlantic Northern Forest. Northern temperate forests dominate a large portion of Nova Scotia, and the most predominant forest types include spruce-fir conifer followed by mixed deciduous-coniferous forests. None of the resource-extraction industries in Nova Scotia are particularly dominant in terms of their impact on birds: forestry and agriculture are equally important, followed by commercial fisheries, electrical generation and marine transportation.
There are 62 priority bird species on land and 32 priority bird species in marine habitats. Wetlands are used by the greatest number of priority bird species (45%), while 35% use forests and 34% use cultivated and managed areas. There is a variety of current and potential threats to the region’s avifauna.Table 1 lists the Priority Bird Species.

Important Bird Areas (IBAs)
Interactive Map on IBA Canada

Bird Migration Forecasts
Cornell Lab of Ornithology. “While only truly written for the US, the “Upper Midwest and Northeast” can be read to give some information as to our future. Overall, one could add, say, two-three weeks and have some useful pointers. Also, the one-week wind direction & precip maps do cover the Maritimes and are definitely useful if you care for that sort of predictive weather info. Don’t overlook the four drop-down files under “Species on the Move”. These really remind you of the sequence of all species, based on hard eBird data.” – Rick Whitman on NatureNS listserv Mar 12, 2017

Second Atlas of Breeding Birds of the Maritimes Provinces
“This Atlas is the single most comprehensive, up-to-date information source on the status of Maritimes breeding birds. More than 260,000 records of 222 species are included in the database, including more than 8,700 records of 17 species at risk. Produced as a beautifully-illustrated hard-cover book, the Atlas is complemented by a comprehensive website where maps, results and much else are accessible online.” (Published 2016). The Introductory chapters are highly informative, available in Part 1 and Part 2. Data and descriptive information for all species are given as links to PDFs under the Table of Contents.
The First Atlas survey for the Maritimes was conducted 1986-90, published 1992. The second was conducted 2006 to 2010, published in 2016. As standardized methods were used, comparisons can be made between the two periods, and within the limits of statistical inference, declines and increases or no change are indicated for various species.

Breeding Bird Survey
The North American Breeding Bird Survey (BBS) is the primary source of long-term, large-scale population data for over 400 breeding bird species. Conducted since 1966, this standardized roadside survey relies on volunteer participation. It is coordinated in Canada by Environment and Climate Change Canada’s Canadian Wildlife Service, in the United States by the U.S. Geological Survey (USGS, Patuxent Wildlife Research Center), and in Mexico by the National Commission for Knowledge and Use of Biodiversity (CONABIO). One day a year, during the peak of the breeding season and for as many years as possible, skilled BBS observers run their assigned roadside route(s). Routes consist of 50 stops spaced 0.8 km apart along a 39.4-km route. Participants record the total number of individual bird species heard from any distance or seen within 0.4 km of each stop during a three-minute observation. These data are carefully analyzed on a yearly basis to provide information on bird population trends, relative abundance and species composition and richness at the local, regional and continental scale. BBS data are freely available, and are used by scientists, wildlife managers, educators, and students, as well as by the general public.


Nova Scotia Bird Society
“The Nova Scotia Bird Society has been a focus for birders in this province for 60 years. Serving about 600 members, we have much to offer anyone interested in wild birds. Browse through our web site for a sample of what we do”. Many resources offered in the Library section. Regular meetings with talks, field trips, sessions for beginners and more advanced birders.

Nova Scotia Bird News by Date
A page on the American Birding Association website recording posts to a listserv, with often 10 or more posts daily. View Nova Scotia’s Clearcut Refugees for an example.

MTRI Forest Bird Monitoring
MTRI (Mersey Tobeatic Research Institute) is involved with many bird monitoring projects, including: Caledonia Christmas Bird Count, Noctural Owl Survey; Landbird Species at Risk. Some results are summarized. Opportunities for volunteering.

Bird Studies Canada
“Bird Studies Canada’s mission is to conserve wild birds of Canada through sound science, on-the-ground actions, innovative partnerships, public engagement, and science-based advocacy.” It sponsors a number of citizen science projects.Search for “Nova Scotia” on the website for a variety of docs dealing with NS, e.g. A Loonie For Your Thoughts! Learning About Nova Scotia’s Lakes and Loons; Nova Scotia Nocturnal Owl Survey: Guide for Volunteers.

“eBird is among the world’s largest biodiversity-related science projects, with more than 100 million bird sightings contributed annually by eBirders around the world and an average participation growth rate of approximately 20% year over year. A collaborative enterprise with hundreds of partner organizations, thousands of regional experts, and hundreds of thousands of users, eBird is managed by the Cornell Lab of Ornithology.” Examples of uploads:
e-bird Sightings – Nova Scotia
e-bird Sightings – Halifax

Natural History of Nova Scotia: Birds (PDF) Brief overview
T11.1 Factors Influencing Birds (Page 226), T11.2 Forest and Edge-habitat Birds (Page 227),
T11.3 Open-habitat Birds (Page 231),T11.4 Birds of Prey (Page 233), T11.5 Freshwater Wetland Birds and Waterfowl (Page 236), T11.6 Shorebirds and Other Birds of Coastal Wetlands (Page 241), T11.7 Seabirds and Birds of Marine Habitats (Page 246)

New Brunswick forestry practices impact bird populations, says researcher
CBC Dec 18, 2016 “Even with the changes that have occurred in the landscape, Villard said “it is never too late” to help birds in the province. He noted there are still plenty of forests that haven’t been harvested and could be maintained.” He sees the issue as a political one and encourages the public to start asking questions about how forests are managed. Most of it is directly applicable to NS.

Hans Toom Blog
His seasonal blog posts are illustrated with some of the best bird photography anywhere.

Nova Scotia’s Clearcut Refugees
Post on this website (Mar 12, 2017). “A strong argument for the inhumanity of clear cutting is that we put at risk all animals that are forced into refugee status.” – Soren Bondrup-Nielsen

Crossland: federal Migratory Birds Convention Act ignored as habitat is cut for chips
Post on this website (July 22, 2017). “The federal Migratory Birds Convention Act is supposed to protect nests and nest habitat, but forest harvests continue unabated during the nesting season, with thousands of nests destroyed every spring. Naturalists and scientists speak of the declining chorus of songbirds compared to the past. And how is this practice allowed on our Crown lands, where the very best forest practices supposedly prevail?”

The Role of Riparian Buffers in Forest Bird Conservation
By C. Staicer et al. Final Report for Nova Scotia Habitat Conservation Fund 2005-2006 “Preliminary results are consistent with the two hypotheses of interest: (1) buffers currently on the landscape may not be maintaining several birds of conservation concern, and (2) riparian forest has greater conservation value to certain species than does upland habitat. Another field season is required to obtain a larger data set for more accurate calculation of bird densities and to determine which species are successfully breeding in buffers.”

Keep an eye out for infectious bird disease, says wildlife pathologist
CBC news, Jun 05, 2018 “Trichomoniasis was first documented in Atlantic Canada in 2007…”It looks like it can be transmitted at bird feeders and so we want people to be aware”

Are cats more destructive to Nova Scotia’s forest birds than clearcutting?
Post, June 8, 2018.”NSDNR says Yes. The science indicates that there are far more direct kills of birds by cats year to year than from forestry operations but the indirect effects of extensive clearcutting on short rotations in Nova Scotia are much more damaging in the longer term.”

Dendroica: An aid to identifying Western Hemisphere birds
“Dendroica is an interactive website developed to help students, volunteers and professionals improve their skills at identifying birds by sight or by sound, particularly so that they can participate in nature survey and monitoring programs. The site includes birds from throughout the Western Hemisphere. Participants can contribute new photographs and sound recordings so it will continue to improve over time.”

It’s not trails that disturb forest birds, but the people on them
EurekAlert Nov 12, 2018. Forest trails that are used more frequently for human recreation have fewer birds and not as many bird species – even when the trails have been used for decades. It cites this paper: Effect of Recreational Trails on Forest Birds: Human Presence Matters, by Yves Bötsch et al., 2018. In Front. Ecol. Evol., 12 November 2018. ABSTRACT “Outdoor recreational activities are increasing worldwide and occur at high frequency especially close to cities. Forests are a natural environment often used for such activities as jogging, hiking, dog walking, mountain biking, or horse riding. The mere presence of people in forests can disturb wildlife, which may perceive humans as potential predators. Many of these activities rely on trails, which intersect an otherwise contiguous habitat and hence impact wildlife habitat. The aim of this study was to separate the effect of the change in vegetation and habitat structure through trails, from the effect of human presence using these trails, on forest bird communities. Therefore we compared the effects of recreational trails on birds in two forests frequently used by recreationists with that in two rarely visited forests. In each forest, we conducted paired point counts to investigate the differences between the avian community close (50 m) and far (120 m) from trails, while accounting for possible habitat differences, and, for imperfect detection, by applying a multi-species N-mixture model. We found that in the disturbed (i.e., high-recreation-level forests) the density of birds and species richness were both reduced at points close to trails when compared to points further away (−13 and −4% respectively), whereas such an effect was not statistically discernible in the forests with a low-recreation-level. Additionally we found indications that the effects of human presence varied depending on the traits of the species. These findings imply that the mere presence of humans can negatively affect the forest bird community along trails. Visitor guidance is an effective conservation measure to reduce the negative impacts of recreationists. In addition, prevention of trail construction in undeveloped natural habitats would reduce human access, and thus disturbance, most efficiently.”

Nova Scotia a key stopping place for protecting North American birds “‘It’s not just for Nova Scotia … these birds link the Americas,’ says conservation scientist Dan Kraus”
Cassie Williams · CBC News · Posted: May 19, 2016.
How Many Birds Disappear Between Migration Seasons? We Now Have a Clue.
Audubo, By Purbita Saha Winter 2018

Denise B. Whynot , B.Sc. (Hon) thesis, Acadia University, 1996

Silviculture with Birds in Mind Options for Integrating Timber and Songbird Habitat Management in Northern Hardwood Stands in Vermont
Audubon Vermont 2011

Long‐term declines of European insectivorous bird populations and potential causes
D Bowler et al. 2019 Conservation Biology”…Our findings suggest that the decline of insectivores is primarily associated with agricultural intensification and loss of grassland habitat. The loss of both seed and insect specialists indicates an overall trend toward bird communities dominated by diet generalists.”

Evaluation of an Automated Recording Device for Monitoring Forest Birds
LISA A. VENIER et al, 2012. Wildlife Society Bulletin 36(l):30-39; 2012; “ABSTRACT Monitoring of forest songbirds via auditory detections during point surveys can be enhanced by using preprogrammed recording devices. DuringMay-July 2008, we compared boreal forest bird surveys conducted with SM-1 bird song recorders (Wildlife Acoustics, Inc.) with field surveys by observers and surveys recorded with the E3ABio-Acoustic MonitorKit(River Forks Research Corp.)in Ontario,Canada, to evaluate the utility of the SM-1 to generate reliable detections of forest birds. The SM-1 surveys identified, on average, 8.95 species, 0.76fewer species per 10-minpoint count than field surveys (x = 9.71 species) and 1.26 fewer species than the E3A (x = 10.21 species). SM-1 surveys also identified on average 11.6 individuals per 10-min count, 2.5 fewer than field surveys (x = 14.1) and 2.3 fewer than E3A surveys (x = 13.9), respectively. The lower number of SM-1 detections, however, was less than the reduction in detections made by field surveys later as compared to earlier in the breeding season. This suggests that SM-1 recorders setup early in the season would detect more birds than field surveys stretching lateinto the season. Moreover, lower detections with the SM-1 could be easily offset by collecting an additional 10-min sample on another day. Most species were detectedequally well by all 3 methods with a few exceptions. Unattended recording devices are especially advantageous in situations where the number of experienced observers is limited, where access difficult, where multiple samples at the same site are desirable, and where it is desirable to eliminate inter-observer, time-of-day and time-of-season effects. © 2011 The Wildlife Society.”

Wildlife Acoustics
“Wildlife Acoustics is the leading provider of bioacoustics monitoring technology for scientists, researchers, and government agencies all over the world.”

Those April Birds
Marcia Bonta blog, April 1, 2020. For Pennsylylvania, perhaps add 3 wks for NS

The Cornell Lab Bird Academy
Many high quality resources for the curious, the beginning birdwatcher, and the advanced birdwatcher. It offers a wide array of paid and fairly pricey online courses, 100s of free videos, a variety Learning Games (by age categories) and open lectures

White-throated sparrows change their tune from 3 notes to 2
Hina Alam · The Canadian Press on CBC

An evening of owls
Birds Canada – Atlantic Region. “A webinar made by our passionate biologists with the Nocturnal Owl Survey program in the Atlantic region! Learn how to identify Atlantic owls, cool facts about owl species, and how data collected by Nocturnal Owl Survey volunteers, as well as other research programs, contribute to our scientific knowledge of owls and their conservation. This webinar was recorded on 24 February 2021.”

In northern Maine, forestry practices create shifting habitat for migrating songbirds
By Tux Turkel The Press Herald Aug 8, 2021

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