andorinhão-de-rabo-curto vs maria-te-viu

The Short-tailed Swift and Yellow-crowned Tyrannulet are unlikely to be confused due to their distinct shapes and behaviors. The swift is a fast-flying aerial insectivore with a streamlined body and short tail, while the tyrannulet is a small perching bird with a stubby bill and semi-concealed yellow crown.

Look for flight behavior: Swifts are constantly in flight, while tyrannulets are often perched. Note the tail: Short-tailed Swift has a notably short tail compared to the perching Yellow-crowned Tyrannulet. Check for wingbars and crown: The tyrannulet has yellowish white wingbars and a semi-concealed yellow crown, which the swift lacks.

The Short-tailed Swift is larger and more streamlined compared to the smaller, more compact Yellow-crowned Tyrannulet.

The Short-tailed Swift has a uniform dark plumage, whereas the Yellow-crowned Tyrannulet features yellowish white wingbars and a dark gray face.

The Short-tailed Swift is often seen in fast, direct flight high in the sky, while the Yellow-crowned Tyrannulet is more likely to be perched or flitting among branches.