American Cliff Swallow
Petrochelidon pyrrhonota
The cliff swallow's average body length is 13 cm (5.1 in), and they have short legs and small bills with relatively long pointed wings. Adult cliff swallows have an overall dark brownish plumage covering both their back and wings, and they have a characteristic white forehead, rich red-coloured cheeks with a dark throat, basic white underparts and a buffy-coloured rump. In good lighting conditions, their crowns and mantle feathers are iridescent. Voice: The social structure of these cliff swallow colonies has evolved a complex vocalisation system. Five vocalisations have been identified, which are used by both juveniles and adults for different reasons. These vocalisations are structurally similar across the age groups and can be described as begging, alarm, recognition, and squeak calls, all with some variations.
ID text from Wikipedia, CC BY-SA 4.0
Cave Swallow
Petrochelidon fulva
The cave swallow measures 12 to 14 cm in length and weighs 19 g on average. The largest of the five subspecies, P. f. pallida, has an average wing length between 107.0 and 112.3 mm; the smallest subspecies, P. f. aequatorialis, has an average wing length between 93.0 and 93.5 mm. Differences between the sexes are minimal, both are similar in size and weight and are difficult to distinguish from their plumage. It has grey-blue upperparts and brown-tangerine forefront and throat. Voice: Cave swallow chicks begin giving faint calls shortly after hatching. As the chicks develop their calls become louder and more aggressive. These calls allow the chicks to communicate to the attending parent(s) their basic needs, such as hunger.
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
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Play today's Daily BirdPhotos and recordings are credited to their authors under the licence shown. Full profiles: American Cliff Swallow and Cave Swallow.