(Latvian Public Broadcasting) The days are longer and everything is waking up after a long, hard winter. Spring is also the time when migratory birds return to Latvia. But which ones, and how can you recognize their songs? Here's another selection of the original twittersphere's greatest hits so that by the time you're swinging lazily in a sun-drenched hammock you won't even need to open your eyes to know what's up in the branches above. The recordings are courtesy of ornithologist Edmunds Račinskis, with photographs from Jānis Jansons. Yellowhammer This little sparrow-sized yellow-brown bird can be found here all year round. Interestingly, each male bird sings only one particular 'dialect song', and any area is usually inhabited by Yelowhammers singing in a single dialect.