REMARKABLE NESTING AND BROODING SITE FIDELITY EXHIBITED BY THE THEROPOD DINOSAUR PETROCHELIDON PYRRHONOTA (APODIFORMES, MANIRAPTORA, COELUROSAURIA) DURING HEAVY CONSTRUCTION AND DEMOLITION ACTIVITIES IN DINOSAUR NATIONAL MONUMENT

Birds (i.e. the still living theropod dinosaurs) can be a touchy lot, especially when it comes to disturbances around a nest. They are generally sensitive to noise and activities occurring in the nesting area, especially when these are on a sustained basis. So it is quite remarkable to have watched Cliff Swallows (Petrochelidon pyrrhonota) nesting under the eaves of the gull-wing roof of the Quarry Visitor Center.

The quarry construction began in late April well before the swallows arrived to nest. The building has been the site (both inside and out) of pounding, yelling, hammering, large gas-powered lifts raising and lowering people and equipment, the building of the giant box enclosing the quarry face, a great deal of truck and car traffic,  large pneumatic pavement busters, jackhammers, abatement teams with their exhaust systems, construction dumpsters being filled with wood, metal, light fixtures, and all sorts of recyclables, cutting and removing of windows and frames, tearing out of drywall, tearing out of 2x4 framing, tearing up of roofs, and tearing down of cinder block walls, etc. but NONE OF THIS has had any effect on the three colonies of birds that selected the eaves as the place to build their nests, lay and hatch eggs, and feed their young. Up close I observed  birds flying in and out of nests within 5 feet of welders in a crane basket using acetylene torches to cut away upright I-beams. The birds even carried on as normal while the 28,000 pound crane was pulled out from the Quarry Visitor Center, passing only a few feet below their nests (see red arrows in photos pointing out part of one colony).

Cliff Swallows have been nesting under the Quarry Visitor Center eaves as long as I have been at the Monument (30+ years) and were doing so well before I arrived. Obviously they find it an appealing location. However, not to abandon the nests during the outrageous amount of construction going on within feet of them is truly remarkable. But then again, would you really expect anything less of a theropod dinosaur?

Photos courtesy of Dinosaur National Monument.