researchers studied the food‑obtaining behavior of the bird known as parus major. in the wild, the birds can obtain food by finding it themselves or by taking advantage of the efforts of other birds via scrounging (e.g., stealing the food of others, joining food patches found by others). to investigate this behavior, researchers set up a puzzle-box where the bird slides a door to the side to reveal food, and the door stays open long enough for a non-solving bird to also take some of the food. the researchers used radio-frequency identification (rfid) tags to individually track data for each bird. they also used cameras to distinguish when a bird employed the producing strategy of solving the puzzle from when a bird surrounded by taking food after a different bird solved the puzzle. the researchers examined if the birds tended to generalize across the producing and scrounging strategies, if they specialized in a strategy, or if they showed some other pattern of food‑obtaining behavior. the histogram shows the proportion of each bird's total visits to the puzzle box that were scrounges. the frequencies indicate the number of birds whose visits to the box have the specified proportion of scrounges. only birds with at least 50 visits are included.