Forest Bird Monitoring Program
In 1989, the Vermont Institute of Natural Science (VINS) initiated the Forest Bird Monitoring Program (FBMP) to track long-term population trends of forest interior birds. The FBMP utilizes highly skilled volunteer birders to assess the population status of species breeding within large tracts of contiguous forest. The scope of the FBMP is unique in the Northeast, as no other long-term avian census in the region collects habitat-specific baseline data across a broad range of forest types.

Rationale
While numerous recent studies have documented declines in many species of migratory songbirds inhabiting fragmented landscapes, few data have been collected from protected forests in the Northeast to corroborate those declines. Accelerated rates of fragmentation have resulted in increased rates of nest predation and brood parasitism, which have contributed to declines in many breeding populations. When coupled with losses of forest habitats in Latin America and the Caribbean, it becomes critical to understand how these changes affect the diversity and abundance of forest birds.
To more clearly understand the effects of habitat fragmentation on birds, it is critical to collect long-term population trend data from both impacted areas and from protected, non-fragmented habitats. Data from protected sites serve as controls with which to assess population changes due to local or widespread environmental changes. VINS' Forest Bird Monitoring Program provides this important control data by sampling breeding bird populations at interior forest sites in Vermont and across the Northeast, most of which are protected as conservation lands.

Survey Methods
FBMP study sites have been established in 9 forest community types in Vermont. In addition, our offshoot project, Mountain Birdwatch, monitors birds in the high elevation montane-fir forests throughout Vermont, New Hampshire, Maine, New York, and Massachusetts. During 2 annual June visits, volunteer observers census breeding birds at 5 point count stations spaced 200 meters apart. At each station, observers record all birds seen and heard in 2 distance classes (within and beyond 50 meters) during a 10-minute sampling period.

This monitoring scheme is capable of detecting fairly small annual population declines (<5%), even for species with relatively small sample sizes and high variability, especially after 15 years of monitoring. As few as 10 years will be required to detect 2% annual declines in commonly-encountered species such as Black-throated Blue Warbler (Dendroica caerulescens) and Ovenbird (Seiurus aurocapillus). Additionally, detailed habitat information is collected at each study site allowing FBMP results to be correlated with landscape attributes, providing a better understanding of how different forest features affect bird populations in Vermont.

Recent trend analyses of the FBMP data set have revealed significant declines for several species, including Canada Warbler (Wilsonia canadensis), Black-throated Blue Warbler, and Eastern Wood-Pewee (Contopus virens). In addition to raising concerns about the conservation status of these species and reinforcing the importance of long-term monitoring, these results have spawned additional research projects. These include an investigation of Canada Warbler population demographics and habitat requirements, as well as an evaluation of the effects of 1998 Ice Storm on Breeding Birds. To view a brief summary of trend analyses conducted using FBMP data from 1989 - 2000, click here (.pdf, 263 kb).

The FBMP is a statistically powerful monitoring program that provides habitat-specific information about breeding bird populations in unmanaged, interior forests. It has already provided conservation biologists with useful results for comparison to those from other monitoring programs, in order to help guide natural resource planning for the conservation of biodiversity.

Take the FBMP Bird Identification Quiz