Ruddy Woodcreeper vs Plain-brown Woodcreeper

The Ruddy Woodcreeper and Plain-brown Woodcreeper are similar in appearance but can be distinguished by bill shape and behavior. The Ruddy Woodcreeper has a short, stout, fairly straight bill and is highly dependent on army ant swarms, while the Plain-brown Woodcreeper has a black bill and is not an obligate ant follower.

1. Bill Shape: Look for the Ruddy's short, stout, straight bill versus the Plain-brown's black bill. 2. Facial Markings: Note the Plain-brown's weak supercilium and malar stripe. 3. Behavior: Observe if the bird is following an army ant swarm, suggesting Ruddy Woodcreeper, or foraging independently, which may indicate Plain-brown Woodcreeper.

Both species are similar in size, typical of woodcreepers.

The Ruddy Woodcreeper has grayish lores and lacks prominent facial markings, while the Plain-brown Woodcreeper features a weak supercilium and a prominent malar stripe. The Plain-brown is also more rufescent overall.

Ruddy Woodcreeper is often found with army ant swarms, whereas the Plain-brown Woodcreeper forages both with and without ants, sometimes with monkey troops.

Both species inhabit similar forest environments, often in mixed-species flocks.