“That’s a Really Sexy Bracelet” chronicles researchers mistakenly skewing their data by banding male Red-winged Blackbirds (Agelaius phoeniceus) with red bands. Not realizing at the time how important red coloration on males is for mate selection, females view the males signature red epaulettes as a sign of health and virility. This human intervention via banding caused those males to have an unintended twofold increase in their harem size. This is illustrated by a red-banded male Red-winged Blackbird perched on a cattail performing its mating ritual. The male is singing and has extended his tail and wing feathers to showcase his red epaulettes to attract the six females that surround him, unwittingly influencing them with his red band. Researchers have since switched to using plain aluminum bands to band birds so that their natural behavior is no longer affected.