Like other species of swallow, Tumbes Swallow forages for insects in flight.
Tumbes Swallow exhibits vigilant protection of nests. On occasions birds massed together to assist in mobbing predatory species like Peregrine Falcon (Falco peregrinus), American Kestrel (Falco sparverius), and Peruvian Pygmy-Owl (Glaucidium peruanum) (Stager et al. 2012).
Associated with nesting, adults quarrel over loose feathers, causing individual feathers to change 'hands' several times before being placed in a nest cup (Taylor, personal observations); this behavior is widespread in Tachycineta.