There is a certain change in bird activity in the area as migration season is in full swing. Some birds are just passing by, others are arriving to spend winter here. With the changes in weather throughout the world many birds are migrating less or skipping the whole ordeal altogether (for example some turkey vultures are no longer leaving during summer - our neighboring family still does though, and they are back).
I noticed how much more bird sounds we have by the end of September and since then it just continues to multiply and change. I am using an app to identify birds by call (Merlin Bird ID is my current choice - though there are many) - simply make my phone listen and then I get a list of birds with some additional information. Then I can look them up, find them in my photos of the trees, draw them, and wonder about their names too :)
But for some of the birds I do not need an app to identify them by sound or otherwise. And the other day there was a huge argument between two groups of them which lasted for several hours. I wish I knew what it was about!