A life list, or life-list, is a list of all biological species seen by a person. The action of tracking which biological species you have observed is known as lifelisting. The phrase is particularly common among bird watchers [1] and fisherman, some of whom compete with each other to have the largest list with the most unique species.[2]
Lifelisting can take many forms, as it is up to each individual what they "count" for their list and what they don't. Some birders (also known as bird watchers) will only count birds they see, while others might take a vocalization as evidence enough to add the species to their lifelist. In other cases, a birder might be in a group of people bird watching when only one person sees and identifies the bird, and the others may choose whether or not to add it to their list.
Lifelists in fishing are a bit more complicated. Since there are so many methods of fishing as opposed to the relative simplicity of birding, fisherman disagree what "counts" for their lifelist and what doesn't. Some fisherman will only count fish species that they caught on hook and line, where the hook is fair, and the fish visibly took the bait. Others are less strict, and some naturalists will even keep a lifelist with dipnets, or seines. The most popular form of lifelisting when it comes to fishing is called microfishing, where fisherman will use small hooks on rods lacking reels, targeting small species entirely by sight, often at night. This is particularly effective at building a large lifelist because there are a much greater number of species available to catch when you can target small fishes rather than just large game fish.