OK. The new BTO Nest Monitoring book brought this to my attention.
They appear to be saying there's no breeding Nightjars in Eire. I could be wrong. I'm basing this on my own reading of a small map the book provides. I can't swear there aren't a few pin prick dots on the map of Ireland.
Either way, that got me going. So, I went to BWI and checked what they said. Basically that Nightjars are rocking horse here. Best looked for in a small patch, right down in the far south east. It doesn't specifically say they do or don't breed there.
Now the head wreck: Young guy I know, over in Co. Mayo. This kid 'Gets out and about For Eire'. Up and down mountains. Through what ever landscape the direction puts before him. And he seems to think nothing too special about finding Nightjars eggs on the tracks through the vast pine plantations
So; What's going on here? Are Nightjar known to breed in Mayo? Or, could this simply be yet another case of a Dog barking where there's no one around to hear him?