is 90% polarized. In experiments investigating polarized light as a signal in mating, it was found that when a female's wings were shown behind a depolarizing filter, she was approached at a significantly lower rate than when her wings were shown behind a non-depolarizing filter. It has been suggested that the high degree of iridescence displayed by H. cydno can be attributed to their forest understory habitat, which generally has less-direct sunlight. Multiple matings H. cydno females are known to mate multiply, thus engaging in polyandry. There are many possible benefits to females mating multiply that may conclude more robust progeny, more allocation of resources, or other benefits. Physiology Macrolide scent gland extracts Research done on H. cydno in Costa Rica suggests that the species has 12- and 14-membered macrolide scent gland extracts which have a C-18 skeleton. They are derived from linolenic, linoleic, and oleic acids and have an S configuration. According to the study, other species' desire and ability to hybridize with H. cydno was not affected by their possession of macrolide scent gland extracts. Social behavior In an experiment by Mirian Medina Hay-Roe and Richard W. Mankin, field-collected H. cydno females were found to produce wing clicks when interacting with members of the same species. Wing clicks are made in short sequences of three to ten clicks, at a speed of approximately ten clicks per second. They demonstrated this behavior during the day and at roosting time, when individuals came close to one another so as to almost touch one another's head or wings. This behavior was also observed during aggressive interactions with H. erato females. When an experimental group of H. cydno were moved to a greenhouse and allowed to reproduce, the first generation of adults born in the greenhouses did not demonstrate wing-clicking behavior. The frequency of wing clicking peaked at 1075 Hz, which is close to the 1200-Hz frequency peak of auditory sensitivity in H. erato. This further suggests that communication both between and within species may be facilitated through this behavior. References cydno Butterflies described in 1847