- Lacrimose Mountain Tanager
- Large-billed Tern
- Laughing Dove
- Least Sandpiper
- Lesser Blue-eared Starling
- Lesser Kiskadee
- Lesser Rhea
- Lesser Whitethroat
- Lesser Yellowlegs
- Line-cheeked Spinetail
- Little Bee-eater
- Little Blue Heron
- Little Woodstar
- Lizard Buzzard
- Long-billed Starthroat
- Long-tailed Glossy Starling
- Long-tailed Hermit
- Long-tailed Meadowlark
- Long-tailed Mockingbird
- Long-tailed Sylph
- Long-tailed Tit
- Long-whiskered Owlet