Since the 1890s, we've been building machines that wait in our place, in the dark, for something to move. This is the story of how a thread across a trail became a sensor that can feel heat, and what we learn when we really look. In this Episode George Shiras: the Michigan naturalist and early wildlife photographer who rigged the first trip-wire camera traps in the 1890sPyroelectricity: the physical property that lets a crystal generate a faint electrical charge when its temperature changesThe Fresnel lens: how a design borrowed from 19th-century lighthouses now focuses invisible infrared light onto motion sensors in camera traps, driveway floodlights, and burglar alarmsThe Haíɫzaqv Nation's coastal wolfs: How a camera trap on the coast caught a wolf doing something scientists didn't know wild wolves were capable ofMachine learning classifiers: how citizen scientists trains algorithms to sort real animal sightings from the false alarms Colorado's gray wolf reintroduction: the closely monitored 2023 reintroduction effort and recent events Episode Music James Opie / Nihilore, CC BY 4.0Hands Clasped at the End of the WorldThe Murky DeepYou Saw the Signs But Never Acknowledged Them Additional Reading Cecco, L. (2025, November 20). Raiders of the lobster pot: Wily wolves learn to haul in Canadian crab traps. The Guardian. https://www.theguardian.com/world/2025/nov/20/canadia-british-coumbia-sea-wolves-learn-to-loot-crab-traps-for-bait Davenport, J. (2025, August 31). Wolf encounters & insights: 2025 newsletter. Churchill Wild. https://churchillwild.com/wolf-encounters-insights-2025-newsletter-by-jad-davenport/ Keller, H. J. (2000, May 11). 30 years of passive infrared motion detectors: A technology review [Paper presentation]. OPTO/IRS2, Erfurt, Germany. https://jvs.de/Carclo_Fresnel/pdf_content/2000-05_irs2paper_Hans_j_Keller.pdf Longwell, A. (2025, July 17). WATCH: Colorado Parks and Wildlife shares first footage of state's newest wolf pups. Vail Daily. https://www.vaildaily.com/news/colorado-wolf-pup-video-routt-county/ Ross, T. (2026, August 10). Colorado hunter thought wolf shot and killed in January was a coyote. The Colorado Sun. https://coloradosun.com/2026/08/10/colorado-hunter-kills-wolf-thinking-it-coyote/ Shiras, G., III. (1906, July). Photographing wild game with flashlight and camera. The National Geographic Magazine, 17(7), 367–423. Shiras, G., III. (1908, June). One season's game-bag with the camera. The National Geographic Magazine, 19(6). Shiras, G., III. (1935). Hunting wild life with camera and flashlight: A record of sixty-five years' visits to the woods and waters of North America (Vols. 1–2). National Geographic Society. https://archive.org/details/HuntingWildLifeWithCameraAndFlashlight.Volume121935Copy Slade, R. (2026, June 4). The outdoorsman who made wildlife photography a big deal for National Geographic. National Geographic. https://www.nationalgeographic.com/history/article/george-shiras-iii-wildlife-photography Support the show 💚 This show is independently produced. You can support the show by joining the show's Patreon. Patreon members get additional content and help make the show possible. You can also donate via Buy Me a Coffee. If you enjoyed this episode, please consider leaving a rating and review on Apple Podcasts or Spotify. And don't forget to sign up to receive Notes from the Machine with each episode.