By Nick Lund, Maine Audubon
The long-awaited results from the new Maine Bird Atlas are finally here! Thousands of observers collaborated between 2018 and 2022 to collect information about Maine bird populations, resulting in the first comprehensive census since 1983 when the Atlas of Breeding Birds in Maine was published. The findings reveal some dramatic changes for Scarborough’s birds.
The atlas was a collaborative effort directed and funded by the Maine Department of Inland Fisheries and Wildlife, with coordination, editing, and publication led by Maine Natural History Observatory in partnership with Maine Audubon and Biodiversity Research Institute. It is not only a bird book, but it also represents the largest natural history collaboration and statewide resource assessment ever undertaken in Maine.
Photos clockwise from top: Willet photo: KenCanning; Glossy Ibis Photo: Megan Maher/Maine Audubon; Saltmarsh Sparrow Photo: Mitch Hartley/USFWS; Nelson’s Spar-row: Remydee1 – Own work, CC BY-SA 4.0
The Scarborough-specific findings are noteworthy. Topping the list is the continued importance of Scarborough Marsh. Maine has lost between 25 and 50% of its saltmarsh habitat since European settlement, according to the atlas, and a whole suite of bird species uniquely adapted to saltmarshes remain threatened by habitat loss from development, disturbance, and especially sea-level rise, which increases the frequency of nest flooding during higher tides.
Populations of one saltmarsh-dependent species, the Saltmarsh Sparrow, are declining by as much as 12% annually. The species was listed as Endangered in Maine in 2023 and is currently under review for federal protection. Scarborough Marsh is just one of two locations in Maine where Saltmarsh Sparrows were found breeding in both the 1983 and 2022 atlases. Other marsh birds like the Nelson’s Sparrow and Willet rely on Scarborough Marsh as one of their few nesting areas in Maine.
The new atlas also highlights Scarborough Marsh’s role as a beacon for rare or expanding species. Climate change is facilitating the northward expansion of several species of marshland bird, and Scarborough Marsh is often where they show up first. Small numbers of Glossy Ibis were recorded breeding in the Scarborough Marsh area in the first atlas, but the species has undergone a 500% increase in its Maine breeding range since then, one of the species that has expanded the most since 1983.
Elsewhere, one of the major revelations of the new atlas is the growing impact of suburbanization. Scarborough, like many greater Portland communities, is highly suburbanized. What were once large forest blocks are being replaced by lawns, fragmented forest, and edge habitat. This new habitat is good for some birds that thrive in dense shrubbery, ornamental trees, and backyard feeders, as well as those species that prefer forest-edge habitat. Carolina Wren, Northern Cardinal, American Crow, Blue Jay, and American Robin have all expanded their breeding populations in Maine since 1983.
Species that require large blocks of contiguous forest, on the other hand, like Ovenbird and Hermit Thrush, as well as those species that are impacted by lights and noise, like Eastern Whip-poor-will, have declined. Cumberland County lost more than 23,000 rural hectares since the prior atlas, representing 39% of its total rural land base, and every region of the state experienced between 15 and 30% of rural land loss. These are just a few of the hundreds of stories included in the new Maine Bird Atlas. Together they paint a fascinating picture; at times frustrating, hopeful, and inspiring.
More about the Maine Bird Atlas…
The results of this project are meant to help guide and inform management decisions and support habitat protection efforts for Maine birds. An online data portal is being developed for use by the public, conservation practitioners, students, land managers, or anyone who wants to be able to access and build upon this work. The atlas is available to pre-order and the book is expected to be available in November. Visit maineaudubon.org/naturalist for more information.
Scarborough Marsh Audubon Center
92 Pine Point Road | 207-883-5100
