No, not the ornithological ones. It’s a term in Irish history for the Irish soldiers who served in foreign armies from the 17th to 18th centuries. I’ve also seen it used to refer to Irishmen serving much later than that in the French army in Sedan in 1870 and the Sino-French war in 1884-1885.
Why am I thinking about this? Easy. On NPR’s Weekend Edition Sunday today I heard Ry Cooder and the Chieftains’ Paddy Moloney talking about a battalion of Irish-American conscripts who deserted the US Army and joined the Mexican Army during the Mexican War in the 1840s to fight against the invading Americans. Cooder and the Chieftains have released an album commemorating their efforts. You can hear the entire album for a limited time at the NPR website. If you like the kind of music the Chieftains have been putting forward for the past fifty years or so, I’m betting you’ll like this. I did.