Tree Swallow (Tachycineta bicolor)
About the Tree Swallow
The tree swallow (Tachycineta bicolor) is a migratory bird of the family Hirundinidae. Found in the Americas, the tree swallow was first described in 1807 by French ornithologist Louis Vieillot as Hirundo bicolor. It has since been moved to its current genus, Tachycineta, within which its phylogenetic placement is debated. The tree swallow has glossy blue-green upperparts, with the exception of the blackish wings and tail, and white underparts. The bill is black, the eyes dark brown, and the legs and feet pale brown. The female is generally duller than the male, and the first-year female has mostly brown upperparts, with some blue feathers. Juveniles have brown upperparts, and gray-brown-washed breasts. The tree swallow breeds in the US and Canada. It winters along southern US coasts south, along the Gulf Coast, to Panama and the northwestern coast of South America, and in the West Indies.
Ecology and behavior
As a member of Hirundinidae, this bird is associated with open air over water, fields, towns and wetlands. It generally feeds by aerial insects. These habits determine where the bird is easiest to observe and explain why a recording often gives the first clue to its presence. Recorded examples on this site are linked to Canada, United States. Local vegetation and weather can change the impression of the voice, but field identification still depends on the same evidence: the perch, surrounding cover and behavior of the calling bird.What to listen for
Calls are short, light and twittering; group rhythm is the main clue. The available recordings are labeled as song, call. On the first listen, follow repetition and phrase length. On the second, decide whether the tone is clear, buzzy, burry, harsh, rounded or thin. On the third, trace pitch direction and the gaps between phrases. A strong field note describes the complete sound before naming the species. Note whether the bird stays hidden or uses an exposed perch, whether phrases accelerate, and whether the voice belongs to a boundary between two habitats. Those details make the recording useful during a real encounter.A field note on this voice
Listening context
The recordings shown here come from Canada, the United States. Because exact recording dates are not available for this conservative note, it is best not to treat any month or season as guaranteed. Local weather, latitude, habitat and breeding cycles can all change when a bird is most vocal. Use the region as a starting point, then look for supporting evidence in the field. Habitat, perch height, light conditions and observed behavior often provide more reliable context than a broad seasonal guess.
Time of day
The exact recording time is not available for this sample. Early morning is often a productive time to listen because many birds sing more regularly then and sound may carry well, but that is a general observation rather than a rule for this species. Birds may also vocalize later while feeding, moving through cover, interacting with nearby individuals or responding to disturbance. Listen for the same kinds of sounds at different times and compare the surrounding behavior.
What this vocalization may suggest
This page contains a song rather than a simple call. Songs are often longer, more structured and more repetitive than short calls. A clear phrase repeated at regular intervals can be associated with breeding activity or the defense of space, although the exact meaning should be confirmed by observation. Shorter or more abrupt notes may accompany movement, alertness or contact between birds. Changes in pace, volume or tone can sometimes reflect heightened interaction, while an evenly spaced delivery may simply be routine.
Understanding pitch
High notes do not automatically indicate courtship, and low notes do not necessarily signal alarm. Pitch works alongside rhythm, repetition, volume and tone. A high, clear phrase may be a territorial song, while high, irregular notes might suggest agitation; some low, soft sounds may simply help birds stay in contact. Rather than focusing on pitch alone, observe what the bird is doing before and after the sound. The most useful field note combines the voice with place, habitat, time and behavior.
Editor's note
These interpretations are intended as listening guidance based on the available recordings and context, not as proof of an individual bird's intent. When exact dates or times are unavailable, this note deliberately avoids claiming them. Strong observations record the date and time, habitat, perch height, weather and behavior before and after the vocalization.
A real field recording of the Tree Swallow. Press play and focus on the rhythm and pitch of each phrase.