The Conservation Science program at the Cornell Lab of Ornithology recently published the first in a series of habitat management guidelines designed to help land managers and owners manage and protect habitat for birds. A Land Manager’s Guide to Improving Habitat for Scarlet Tanagers and other Forest-interior Birds rolled off the presses this past December, offering specific habitat management guidelines resulting from one of the Lab’s first citizen-science projects, Project Tanager. The publication of these guidelines shows how effectively citizen-science projects can contribute directly to bird conservation, but more importantly, the guidelines provide land managers with science-based recommendations that they can use immediately.

As the preface of the 24-page booklet explains, these guidelines are written for two types of land managers: those responsible for large landscapes, such as public lands or entire states, and private landowners who manage small blocks of forest. The booklet first discusses the general concept of forest fragmentation-the process by which large, contiguous forests are broken into small parcels by agriculture, logging, or development. Scientists have known for some time that fragmentation can severely reduce the ability of a forest to support healthy breeding populations of many bird species, so the booklet offers general guidelines for managing forests to benefit many forest-interior birds. These general guidelines include preventing the fragmentation of large forest tracts, minimizing the creation of edge habitats, establishing forested corridors to reduce isolation of small patches, and maintaining structural and plant-species diversity within existing forests.

Then, the booklet focuses specifically on the habitat-area requirements of the Scarlet Tanager. Because habitat requirements for this species vary geographically, recommendations are tailored to conditions in different regions of the tanager’s range. Four “Regional Profiles” provide a map and description of available forest types, Project Tanager results showing forest types used by Scarlet Tanagers, estimates of the amount of mature forest required to sustain breeding Scarlet Tanagers, and a regional summary that briefly presents the most important management strategies for that location. This regional approach provides land managers with information that will be directly applicable to their own areas.

Central to each profile are “Minimum Area Tables.” These tables have several uses, for example, predicting the impacts that proposed management actions or land-use changes will have on the suitability of habitat for breeding tanagers or determining the degree of reforestation needed to increase the likelihood of attracting tanagers to a forest patch. The tables must be used carefully and correctly, however, because the suitability of any given forest patch for supporting tanagers depends not only on the size of the patch but also on the amount of forest remaining in the surrounding landscape, as well as the distance from the patch to the nearest forest of at least 100 acres. For example, a 20-acre woodlot may be unlikely to support tanagers if it is surrounded by agricultural land, but a similar woodlot located close to a large, extensively forested park may be almost as likely to support tanagers as the park itself. Indeed, the complexity of the relationship between tanagers and their habitats is one of the key findings of Project Tanager.

Why did the Lab choose the Scarlet Tanager for its first forest-bird project and first set of habitat guidelines? First, this conspicuous species represents a whole community of forest-dwelling Neotropical migratory birds. Scarlet Tanagers are part of a community of species that share similar habitat requirements and geographical distributions. By meeting the needs of Scarlet Tanagers, land managers also will be improving habitat for dozens of other forest-dwelling birds.