Breanna Putman began questioning whether what she wore affected animals during a study of urban nature. “We were encouraged to wear these bright neon orange T-shirts to identify us as scientists,” she recalls. “I wondered if wearing them in urban habitats and not in rural habitats would mess up my results.”
“We basically found out that, yeah, it could,” says Putman, an ecologist at UCLA.
She already knew that when people wore red or orange, they could get closer to cardinals, flickers and other birds with feathers that matched. Scientists explain this with the species confidence hypothesis. “Being attracted to their own body color may help birds identify partners within their own species, instead of mating with a different species,” Putman says.
So she decided to see if the same held for lizards, starting with western fence swifts. Males of this species have bright blue markings on their throats and bellies, and Putman and colleagues report in PLOS ONE that wearing dark blue made it easier to catch these lizards.
Putman wore T-shirts of different colors ― dark blue, light blue, red and gray ― and measured how close she could get to the lizards before they fled. Then after they ran away, she tried to catch them.
“Lizards responded to color in surprising ways,” she says. When she wore dark blue rather than red, they let her get twice as close before fleeing and were twice as easy to catch once they had fled. Next she wants to see if clothing colors affect behavior in other lizards such as the green anole, which has a reddish-pink skin flap on its neck.
Animals often see people as predators and flee immediately. This work suggests that hikers and ecotourists could minimize disturbances to animals by wearing appropriate colors.
And now that she knows lizards respond to what she wears, Putman has adjusted her own behavior accordingly: “I always wear the same colored shirt across all my study sites.”
Image: Ingrid Taylar, Flickr
Reference: Putman BJ, Drury JP, Blumstein DT, Pauly GB (2017) Fear no colors? Observer clothing color influences lizard escape behavior. PLoS ONE 12(8): e0182146. https://doi.org/10.1371/journal.pone.0182146