Geographic Area Covered by the Nighthawk Survey

The roots of the current SuAsCo/Nashua Nighthawk Survey go back to the 1960s in the SuAsCo Valley when fall nighthawk migrations were tracked from the top of Round Hill in Sudbury, the fields of Heard Farm in Wayland, the drumlin at MA Audubon in Lincoln, Great Meadows in Concord and other nearby areas. During the 1990s the survey effort expanded to other points in the Assabet, Sudbury, and Concord River basins and in 2003 a computerized, near real-time data reporting and analysis system was introduced to integrate the results from the various observation points.

The new reporting system immediately and fundamentally changed the survey perspective in two basic ways. First, the panoramic overview of the new database left little doubt that the great bulk of fall nighthawk migrants were following the major waterways through the SuAsCo valleys. And second, it quickly became apparent that the SuAsCo Valley was simply a small piece of a much larger network of nighthawk migration routes in the area and that if our ultimate goal was to track and analyze nighthawk populations and migration routes over time, then survey horizons would have to be significantly broadened both westward and northward to capture the true scope of total nighthawk flows. Accordingly, in 2004 the survey area was expanded westward to include the Nashua River basin and in 2005 it was pushed both westward to include the northern two-thirds of Massachusetts beyond the Nashua River to the Connecticut River and northward to include the Nashua River in lower New Hampshire. And in 2006, the northward march continued with the addition of the Merrimack River basin up to Concord (NH) with its three major tributaries, the Contoocook, Piscataquog, and Souhegan Rivers, and to the west the lower Connecticut River basin with its two major tributaries in southern NH, the Ashuelot and Cold Rivers

The survey area as it is now constituted thus covers roughly the lower one-third of New Hampshire and the upper two-thirds of Massachusetts and is bounded on the east by the Sudbury, Concord, and Merrimack Rivers and on the west by the Connecticut River. The total coverage area amounts to approximately 3,300 square miles.

Below is a list of the three major river basins and principal tributaries of each within the survey area with web sources of additional information for each river.

Massachusetts Rivers

Map of Massachusetts River Watersheds

1. Merrimac River Basin
• Massachusetts Executive Office of Environmental Affairs - Merrimack River Watershed
• Merrimack River Watershed Council
1. SuAsCo Rivers
• Massachusetts Executive Office of Environmental Affairs - SuAsCo Watershed
• SuAsCo Watershed Community Council
2. Nashua River
• Massachusetts Executive Office of Environmental Affairs - Nashua River Watershed
• Massachusetts Executive Office of Environmental Affairs - Nashua River Basin Flow Inventory
• Nashua River Watershed Association
3. Souhegan River
• See Souhegan River references under Merrimack River Basin in New Hampshire.
2. Connecticut River Basin
• Connecticut River Watershed
• Connecticut River Watershed Council
1. Millers River
• Massachusetts Executive Office of Environmental Affairs - Millers River Watershed
• Millers River Watershed Council
2. Chicopee River
• Massachusetts Executive Office of Environmental Affairs - Chicopee River Watershed
• Chicopee River Watershed Council map
3. Upper Blackstone River Basin
• Massachusetts Executive Office of Environmental Affairs - Blackstone River Watershed

New Hampshire Rivers

NH Designated Rivers Map

1. Connecticut River Basin
• NH Department of Environmental Services - Connecticut River
1. Ashuelot River
• NH Department of Environmental Services - Ashuelot River
2. Cold River
• NH Department of Environmental Services - Cold River
2. Merrimack River Basin
• NH Department of Environmental Services - Lower Merrimack River
• NH Department of Environmental Services - Upper Merrimack River
1. Contoocook River
• NH Department of Environmental Services - Contoocook River
2. Nashua River
• Nashua River Watershed Association
3. Piscataquog River
• NH Department of Environmental Services - Piscataquog River
• Piscataquog Watershed Association
4. Souhegan River
• NH Department of Environmental Services - Souhegan River
• Souhegan River Watershed Management Plan 2006