Third trip to Paris in September of 2022, but first time I did any birding there.
Bois de Boulogne and Jardin du Luxembourg were the green spaces I birded, and just walking along the Seine, looking at the gulls. 
Overall it was OK for birding, but I did pick up some lifers, such as Eurasian Green Woodpecker, European Robin, Eurasian Jay- all lovely birds. Got great looks but images so-so as I didn't have my big lens.