- Division of Fisheries and Wildlife
Media Contact for Tracking the eastern whip-poor-will
Marion Larson, MassWildlife
Many people recall with nostalgia summer evenings filled with the fast staccato call “whip-poor-will, whip-poor–will” of the bird by that name. In recent years, these distinctive sounds (and birds) have become increasingly rare. Indeed, the eastern whip-poor-will (Antrostomus vociferus) population has experienced annual declines of 4.4% in New England and 6.6% in Massachusetts (since 1966), where it is state listed as a Species of Special Concern. Whip-poor-wills appear to be heavily dependent on fire-adapted pine-oak habitats for breeding, but over the past few decades, these habitats have become scarce due to forest maturation, fire suppression, and development. This change in habitat has undoubtedly contributed to the dramatic decline in abundance of these nighttime vocalists. Additionally, researchers speculate that elevated mortality rates during migration or on the wintering grounds also may contribute to population declines. However, due to their nocturnal habits, scientists lack basic natural history and ecological information on this species, with little known about the migratory and over-wintering periods.
To gain a better understanding of the eastern whip-poor-will’s annual cycle and to support bird conservation actions, we initiated a project with Dr. Marja Bakermans at the Worcester Polytechnic Institute. Using GPS technology we are documenting the migratory routes and over-wintering locations of whip-poor-wills nesting in Massachusetts. Additionally, we are studying the timing and duration of their migration as well as their movements and habitat use during both migration and winter periods.
Our banding efforts focused on three locations across Massachusetts: Joint Base Cape Cod, Bolton Flats Wildlife Management Area (WMA), and Montague Plains WMA. These sites contain the preferred pitch pine-scrub oak woodlands that whip-poor-wills use for nesting. To lure territorial whip-poor-wills into mist nets we played recordings of their songs and calls. Once captured, we recorded morphological measurements and the sex and age of each bird. Next, we attached a tiny GPS tag weighing 1 gram to the bird’s back using a leg-loop harness. During May and June of 2018, we fitted 27 whip-poor-wills with a GPS data logger. The next challenge was to recapture these same individuals a year later in order to retrieve the GPS tags and download the stored data.
This spring, with fingers crossed, we went out and set up mist nets before dusk in the same three study sites. Whip-poor-wills are most active soon after dusk, and our nets are made of a fine mesh that birds cannot see once it is dark. After sunset, we played calls to lure males (or females), which would come in to defend their territory. The staff checked nets every 20 minutes, extracting captured birds and bringing them to a centralized location for banding and data collection. Much to our excitement, the very first bird that was captured had a GPS tag, and in total, we were fortunate to recover 12 tagged birds from last year providing us with a tremendous amount of data on the birds’ migration, over-wintering locations, and habitats. We also caught and tagged an additional 19 birds for the project.
We are just starting to analyze the data, but initial information has revealed that most of our birds wintered in Mexico with one going as far south as Honduras. Interestingly, instead of taking the most direct route of flying across the Gulf of Mexico, the birds appeared to avoid that option and instead took a longer land-based route. The data collection portion of the project will be wrapped up next year after we try to capture this year’s tagged birds. We are eager to learn more and publish our results so the information can be used to develop full annual-cycle conservation plans ... stay tuned!
This story, written by MassWildlife's State Ornithologist, Andrew Vitz, will appear in the next edition of Massachusetts Wildlife magazine—coming to subscribers' mailboxes in late July. The July edition also includes articles about waterfowl research, frog hunting, and milkweeds. Learn more about the magazine and how you can subscribe.