What was found
Researchers monitored cardiac activity in two urban-tolerant orb weavers, the Jorō spider (Trichonephila clavata) and the golden silk spider (Trichonephila clavipes), while exposing them to traffic noise.
Jorō spiders with previous exposure to loud traffic showed the strongest heart-rate increase. Golden silk spiders responded differently, with changes more closely related to their baseline heart rate than to prior noise exposure.
What makes that interesting
Presence alone can make a species look unaffected by an urban environment. Physiology can reveal subtler effects, but the scale matters: the cardiac responses here were mild compared with those caused by severe stress.
The most accurate picture is therefore neither “traffic does nothing” nor “traffic is devastating them.” These spiders showed detectable responses while also appearing comparatively resilient.
Why it matters
Noise-pollution research has focused heavily on vertebrates. Measuring hidden responses in spiders broadens the picture and gives researchers a way to compare how different invertebrate species cope with human-altered environments.