Sparrow using Swallow Nest. : r/Ornithology
What type of bird builds nests on window sills? - Quora
House Sparrows Taking Over Cliff Swallow Nests
NestWatch Managing House Sparrows and European Starlings - NestWatch
Identify please. There is what I believe a house wren coming and going. : r/ Ornithology
Identifying Bird Nests on Farm Structures
Cliff Swallow - Montana Field Guide
House Sparrows Kill Native Birds Here's How to Save Them
Plumages, Molts, and Structure - Barn Swallow - Hirundo rustica - Birds of the World
Breeding - Barn Swallow - Hirundo rustica - Birds of the World
Swallow - Wikipedia
Where do house sparrows nest? - Quora
I saw 3 Bank Swallows using the same burrow. Any idea what's going on here? Is it a throuple? Is it a previous year's offspring helping out or what? : r /Ornithology
ADW: Petrochelidon pyrrhonota: INFORMATION
House Sparrows Taking Over Cliff Swallow Nests
Cliff Swallow : Minnesota Breeding Bird Atlas