During the summer months, adult animal numbers stabilize, and the drive to establish a territory means you’re likely to have the same individuals active outside your windows for the majority of summer.
If you’ve become familiar with the animals in your neighborhood, chances are you’ll see some of the same individuals again year after year.
Birds that don’t migrate and stay in residence year-round, like chickadees, often have a tendency to stay in the same area, which means you’ll be seeing the same individual birds outside your window across seasons.
When it comes to smaller animals, like lizards and insects, all bets are off for how many unique individuals are present outside your window.
Many animals have enough individual variation that you can keep track of them using their natural unique marks and scars.