With the online publication of Responsible Primate-Watching for Tourists, we would like to continue to promote the hobby/sport of primate-watching, and its associated activity, primate life-listing. The idea for this derives from birdwatching—one of the most popular hobbies in North America, Europe, and Australia, and increasingly elsewhere across the world. Birdwatching has been with us for a long time, and its popularity is growing. It has benefited by an ever-increasing number of guidebooks that cover the entire planet and, in the past 15 years, by the availability of new sophisticated equipment such as phone apps for bird identification using visual and sound information. The most striking example is the phone app Merlin (https://merlin.allaboutbirds.org), released for free by the Cornell Laboratory of Ornithology, that has an average of 700,000 active users per month, and counting. Huge progress has resulted from more websites connecting birders around the world, and from global bird databases such as eBird (https://ebird.org), housed by the Cornell Laboratory of Ornithology at Cornell University (USA), or regional or national databases, such as the Euro Bird Portal (https://eurobirdportal.org) where birders report their observations. All of this has been good for conservation, stimulating awareness of and love for birds, and providing many ecotourism-based economic opportunities for communities living in or near bird habitats. The passion for birds has become a multibillion-dollar industry, with at least some of the benefits accruing to the bird-rich countries of the tropics.