Night hike reveals the glow of night: lichens, moths, and citizen science in Patuxent River Park

In a winter night hike along the Patuxent River watershed, NPR’s Shortwave follows naturalists as they explore the forest after dark. Using UV lights, the group reveals fluorescent lichen patches, identifies yellow Pixine subscearia and orange Pixine cerridiata, and explains fluorescence as a sunscreen against ultraviolet damage. The night unfolds with moths drawn to mercury lamps, an owl-calling demonstration, and moments of playful discovery among adults who behave like kids on a field trip. The episode also spotlights iNaturalist and city-wide bio blitzes, underscoring how community science deepens our relationship with land, biology, and the magic of a winter night outdoors.

Introduction: A winter night hike with naturalists

The episode sets the scene with Emily Kwang and Burley McCoy taking listeners on a night hike through the Patuxent River watershed in Maryland. Bundled in winter coats, they join a crew of naturalists and scientists who are eager to observe the forest when most life quiets down. The group is described as a community of observers who collect data, share observations, and educate others about the environment. The setting along the Patuxent River, which flows toward the Chesapeake Bay, provides a gateway to winter ecology and the thrill of nocturnal discovery.

As the night unfolds, the hosts emphasize that this is not about conquering the wild but about quietly listening, learning, and noticing the life that remains active under the cover of darkness. The segment also introduces the idea that winter, far from barren, is a time for energy conservation and a shift in how organisms thrive in cooler, darker months.

quote

"winter is all about slow down, rest, conserve your energy" - Burley McCoy

Bioluminescence and fluorescence: lichens under ultraviolet light

The episode dives into a patch of tree bark where lichen glows under a UV flashlight. Serenela Linares, a mushroom expert and nature-walk leader, introduces the science of fluorescence in lichen, explaining that different colors signal distinct species. Natalie Howe, an ecologist with the USDA, clarifies that fluorescence is a protective response that helps lichens resist ultraviolet light damage. The hosts and experts discuss how two primary lichens—Pixine subscearia (yellow) and Pixine cerridiata (orange)—glow in neon hues when illuminated by UV light, turning an ordinary patch of bark into a living biology lesson. The moment combines field observation with an accessible explanation of how organisms adapt to sun exposure and environmental stressors.

quote

"lichens fluoresce as a protective response against ultraviolet light damage from the sun" - Natalie Howe, ecologist with the USDA

Nighttime life, owl calls, and Moth watching

As the night deepens, the naturalists divide into small groups, moving through pockets of forest, tracing sounds, and discussing winter adaptations. Matt Felperin, a roving naturalist with Nova Parks, announces owl calls and shares a mnemonic for attracting barred owls: "Who cooks for you, who cooks for you all?" This interaction becomes a vivid example of how field techniques and local knowledge empower people to observe wildlife. The segment highlights the social dimension of outdoor science, showing grown adults engaging with nature with childlike curiosity—touching damp logs, following microhabitats, and marveling at tiny creatures like isopods and juvenile crustaceans. The night becomes a space for hands-on learning and shared wonder rather than a strictly scripted science narrative.

quote

"Who cooks for you? Who cooks for you all?" - Matt Felperin, roving naturalist with Nova Parks

iNaturalist, bio-blitz culture, and community science

The episode foregrounds iNaturalist as a practical tool for identification and connection, with Anna Kahanui, co-founder of Capital Nature, describing how a community can document biodiversity through apps and citizen science events. The conversation connects the personal joy of observing a forest at night with broader movements like the City Nature Challenge, a multi-generational event that makes science accessible to families and neighbors. The segment emphasizes the value of noticing life forms, recording observations, and learning to name species as a way to deepen one’s relationship to land and seasonal cycles. The idea is to make science a shared, everyday activity rather than something confined to laboratories or classrooms.

quote

"iNaturalist is the app that helps you ID things in the natural world" - Anna Kahanui, co-founder Capital Nature

Bioluminescent fungi and insights into winter biology

The night’s final highlight is the discovery of a honey mushroom and its bioluminescent properties. Serenela Linares explains that in summer these fungi glow with a green light known as foxfire, a phenomenon that may help attract nocturnal animals for spore dispersal. She notes that in winter the bioluminescent activity can wane, illustrating how environmental conditions shape fungal life cycles. The discussion uses the mushroom as a focal point to introduce broader questions about why some organisms glow and how bioluminescence might serve ecological roles in the forest—an invitation to consider the winter forest as a dynamic, luminous ecosystem rather than a dormant landscape.

quote

"in the summertime, honey mushrooms produce a green light known as foxfire" - Serenela Linares

Takeaways: winter ecology, energy, and how to join the next bio blitz

The episode closes by tying the night hike to larger themes of winter ecology and energy conservation. The naturalists encourage readers to explore local nature challenges, such as the City Nature Challenge, and to engage with their communities to observe and protect biodiversity year-round. The conversation reinforces the idea that curiosity, patience, and collaborative learning can transform even a cold, dark night into a productive and joyful scientific experience. The hosts remind listeners to check links on the NPR site to participate in events and to follow Shortwave for future episodes, underscoring the ongoing relationship between public media, science, and local engagement.

quote

"winter is all about slow down, rest, conserve your energy" - Burley McCoy