When somebody disappears abruptly, we say in English that he has "taken French leave". In a similar situation, the French would say that he has "left in an English manner". (There's another amusing example of Franco-British passing the buck. The contraceptive device known in Britain as a "French letter" is designated by the French as an "English overcoat".) So, I'll split the difference and say that my family of mésanges (common tits) has taken Franco-British leave of Gamone.
I had imagined confusedly that the parents, on the eve of their departure for Africa (or wherever they plan to spend summer), would drop in on me for a moment to show me the babies, bid me au revoir (see you next winter), and maybe even thank me for my hospitality. But no, they simply packed up their stuff (maybe during the early hours of the morning) and disappeared, without a chirp. Maybe the family of mésanges will return here next winter, with scores of others, but I'm not sure I'll recognize them. I've never been good at remembering faces. Besides, they'll all have a suntanned look after spending the summer months outdoors in a place like Africa or Arabia.