The sight of glowworms twinkling inside caves has many tourists and cavers drawn to the region. But photographer Jordan Poste took a different approach, capturing their soft illumination with a 60-hour time-lapse video.
Glowworms produce light in special organs at their abdomens, a process known as bioluminescence. They can blink or emit a constant glow, and they can use this light to warn off predators, find mates, or attract prey. The glow also helps them navigate underground or in shallow water.
A recent study found that artificial white light hampered male glowworms’ ability to detect female bioluminescent signals. This could be a problem because the survival of these insects relies on mating. In addition, excessive outdoor lighting can interfere with their habitats, distract them when searching for mates and drown out their glowing signals with excess light.
Glowworms are one of the world’s most endangered species, and their disappearance is often attributed to human activities. In addition to habitat destruction, commercial collection for their luciferin (the chemical that produces light) and pollution may be contributing factors. However, the most pressing threat is probably light pollution. Street lights, vehicle headlights, and even halogen bulbs can interfere with their bioluminescent signals by reflecting off of the insect’s body. In fact, a recent study found that artificial light can reduce the intensity of glowworms’ signals by as much as 90 to 98 percent. The authors of the study suggest that light pollution is a significant factor in declining glowworm populations, and that conservation efforts should focus on reducing the amount of outdoor light.