‘Cold’ butterflies get what they want from males

It’s not her fault. It’s just the way she was raised. Female butterflies who grow up in colder temperatures become more aggressive as adults, actively chasing males for sex and food, said researchers at Yale University in study published Thursday in the journal Science.

“Behavior in these butterflies is changed by the temperatures experienced during development,” said study co-author Kathleen Prudic, who looked at female squinting bush brown butterflies, or Bicyclus anynana.

Scientists wondered why some of the females had ornate wing markings that resembled eyes, like the attractive wings found in males who usually have to compete for the ladies’ attention.

When they looked closer at the upbringings of those glitzy females, they found that their early days were marred by a chillier environment than the females who let the males do the chasing.

Comparing the behavior of butterflies who grew as larvae in cozy warm climate of 27 degrees Celsius compared to 17 degrees Celsius, (80 vs 62 degrees Fahrenheit), they found that females raised in warm, moist conditions mated with males with flashy wings.

“However, the roles were reversed in cooler drier climates. Females played the role of suitors and flashed their eye spots to choosy males,” said the study.

But growing up hard could lead to happy endings for females who need to survive in the cold. Males tend to deliver not only sperm but nutrients to the female during mating, so that in the harsher cold, “these male offerings appear to lead to increased female longevity,” the study said.

“Males, on the other hand, become very careful about choosing who they give these resources to because once they do, they live shorter lives.”

AFP