Well-designed monitoring programs provide essential information on distribution, abundance, and population trends. They are used to:
- elucidate species-habitat relationships and measure responses to environmental change.
- evaluate the efficacy of management actions and to adjust them as needed.
- assist in the successful recovery of once-imperiled populations (e.g., Common Loon, Peregrine Falcon).
A useful monitoring program requires repeated, standardized surveys conducted over time.
- Each survey should yield precise and unbiased estimates of the number of individuals present in the population.
- Collecting ancillary data (e.g., weather, habitat conditions) can identify possible causes of observed changes in population size.
By these standards, and despite many ongoing monitoring efforts, populations of many species in Vermont are not adequately monitored.
- Species restricted to patchy or unusual habitats: grasslands, shrublands, boreal forest.
- Species not amenable to survey by traditional methods and require specialized techniques: marshbirds, some aerial insectivores (swallows, swifts), woodpeckers, raptors, owls, nightjars.
The Atlas has a unified but flexible approach, and can provide valuable insights into distributional changes for most breeding species.
- Distribution, although not a perfect index of abundance, is often a close correlate.
- However, data are collected only every 25 years, and distributional changes are often a late, trailing indicator of population size.
Additional, specialized monitoring is needed to sufficiently track Vermont’s bird populations.
- Many programs can be coordinated and largely carried out by citizen scientists.
- A comprehensive program that addresses key gaps in monitoring programs for birds would compliment Atlas data
- Prioritize species for which Atlas data raise “red flags” but are not currently adequately monitored. These include:
- Uncommon to rare, declining ducks and waterbirds (Common Moorhen, Green Heron, Northern Pintail, Blue-winged Teal, Green-winged Teal, Common Goldeneye, American Black Duck)
- Owls (Long-eared Owl, Great Horned Owl, Northern Saw-whet Owl, Eastern Screech Owl)
- Grassland birds (Upland Sandpiper, American Kestrel, Vesper Sparrow, Eastern Meadowlark, Bobolink)
- Shrubland birds (Brown Thrasher, Eastern Towhee, Field Sparrow)
- Aerial insectivores (Cliff Swallow, Bank Swallow, Chimney Swift, Olive-sided Flycatcher)
- Boreal birds (Boreal Chickadee, Gray Jay, Yellow-bellied Flycatcher, Lincoln’s Sparrow, Rusty Blackbird)
- Raptors (Red-tailed Hawk, Red-shouldered Hawk)
- Other species with apparent declines for unknown reasons, including Spotted Sandpiper, Yellow-throated Vireo, Canada Warbler