Report Cliff Swallow Sightings

Cliff swallows © David McIntyre
Cliff swallows © David McIntyre

Cliff swallows, a once-common species in New England have been undergoing a long, slow decline in Massachusetts. Our best estimates of their breeding status and trend in Massachusetts comes from the Breeding Bird Atlas 2, and that suggests that there is cause for concern. The breeding footprint of Breeding Bird Atlas 2 was less than half that of Breeding Bird Atlas 1; they currently are thought to occur primarily in the western part of the state, with a few sites in Essex County. They have all but disappeared from the Cape and Worcester Plateau.

As agriculture has declined in northeast, so have the cliff swallows. Other factors contributing to their decline are introduced house sparrows, which out compete swallows and usurp their nests, and the possibly that pesticide use is influencing their prey is also suspected.

We are conducting a state-wide survey this spring to determine where cliff swallows are breeding in the state, and you can help! Identifying breeding sites is the first step in addressing the decline in this species.


We want enthusiastic folks to help us map both old and currently active colonies. It is simple: if you find a colony or know where an old colony was, use the directions below to drop a pin on a map, and answer a few questions. That’s all you need to do.

Have a look at our Quick Guide to cliff and barn swallows or our identification guide to help you identify the two species. Cliff swallows are fast, aerodynamic fliers. Their breeding “song” is an unmusical, yet endearing squeak that sounds like a rusty gate. Cliff swallows also generally fly higher than other swallows, making tighter turns, as they feed on swarming insects that rise on thermals.


Cliff swallows arrive in Massachusetts in late-April and continue to funnel in through May. Our goal is to identify sites where cliff swallows are actively breeding. Look for swallows from the beginning of May through mid-July. They are active all day, but early morning and evening are their most active hours.


Barn © Mara Silver
© Mara Silver

Cliff swallows like a nice view! You are most likely to find them in areas with open fields, commonly near agricultural areas, nesting under the eaves of barns or occasionally under bridges. They build nests of mud, and sometimes you will find them gathered by puddles gathering nest material.

It is easy to confuse cliff with barn swallows—remember: barn swallows nest inside buildings, cliff swallows nest outside. Barn swallows have longer tails too.

If you have seen them at a particular site in years past, go back and check again at that site. Cliff swallows often return to the same traditional colony, year after year. Farmers are often a great resource for information about locations of breeding cliff swallows as well. We want information regardless if the site is currently occupied or not.

How to Help

If you see swallows flying around a building, check it out from the road! Be respectful and please don’t peer into someone home with binoculars.

Listen for the twitter-squeak breeding call and look for a bottle-shaped mud nest placed under eaves. Some may be old nests that are not used anymore. Try to determine which are occupied by checking to see if the birds are flying in and out of the nests. It may take a few visits to accurately determine the status of a nest.

If you locate a cliff swallow nest sight, or know of a historic site, please report in via our mapping tool.

How to Report 

  • Sign in using the button above to report a sighting. An account is created for you so you can come back later and tell us more about your cliff swallow sightings. 
  • Place the map locator as precisely as possible over the nest site.
  • Fill in the questions.
  • Revisit the site if you think it was an active nest site.

Project Partners

This project is a partnership with Mass Audubon and Dr. Andrew Vitz, the Massachusetts State Ornithologist at Massachusetts Division of Fisheries and Wildlife.