I’ve discovered over the years that the University of Maine campus is a great place to go birding.

I’m not just referring to the possibilities at the Ornamental Gardens – which is a great place to start – but elsewhere, in more trafficked areas, which you might not think would yield as many results.

The library, for instance. This year I’ve been observing several cliff swallows constructing their nests on the ceiling before one of the entrances. Although the campus has quieted down now that the semester is over, there is still a steady trickle of people in and out of the building, but this doesn’t seem to disturb the birds much.

This is lucky for them, for they need all the help they can get in preventing their nests from being taken over by the aggressive European house sparrow, which will also kill any young it may find in the nests.

Cliff swallows originally nested in the Western mountains. The widespread construction of bridges, highway culverts and buildings within the past 150 years has aided these birds by providing them with abundant nesting sites. As a result, they have steadily increased their range across the Great Plains and into eastern North America. However, they were still never common here in the Northeast, and their populations remain low due to the house sparrows’ usurpation of their nests.

The swallows are extremely social birds that nest in colonies. The group of six or seven nests at the library is puny compared to a typical colony of 3,500 nests found elsewhere.

Researchers have discovered that these colonies serve as information centers – birds having little success finding food will observe their neighbors to find out about the location of insect swarms, their main food source. This helps all the members of the colony find food in the quickest, most efficient way possible.

Cliff swallows can be distinguished from Maine’s other swallows (the tree, bank, barn and purple martin), by their squared-off tails and a very obvious light-colored triangular patch on their foreheads, just above their beaks. They have buff-colored rumps and deep chestnut throat patches, and their upper chests and bellies are white, whereas the barn swallow’s is a light tan. Barn swallow tails are also long and deeply forked.

The nesting cliff swallows on campus present an opportunity to observe their behavior and nesting success at close range. However, people wishing to do so must consider the welfare of the birds at all times, taking care not to disturb them. Intentional interference with the birds or their nests is unlawful, as the birds are protected under the Migratory Bird Treaty Act.

Chris Corio, a volunteer at Fields Pond Nature Center, can be reached at fieldspond@juno.com.