It's not unusual for people in workplaces and at home to have different temperature preferences. There may be biological explanations for why it seems that many women feel colder than men in the same room, and it extends to animals. New research has suggested that in mammals and birds, males and females perceive temperature differently. The work, which has been reported in Global Ecology and Biogeography, suggested that the heat-sensing systems of the sexes have an evolutionarily imprinted difference that's related to various aspects of physiology, including reproduction.
This research was based on previously published work on this topic as well as an analysis of birds and bats in Israel. Previous work by study co-leader Dr. Eran Levin has found that male and female bats tend to move to different places during the mating season, and the males prefer cooler spots. The bats found in the caves of Mount Hermon, for example, are all males during mating season, while females can be found in warmer areas by the Sea of Galilee, giving birth and raising pups there.
This phenomenon can be seen in other animals too, like migratory birds, and mammals; males often move to mountain peaks or shady spots while females prefer valleys and areas that get sun.
The scientists hypothesized that migratory birds could help reveal patterns of separation in the sexes because they move around so much, and sometimes even to different climates. To assess migratory birds in Israel, the researchers reviewed data from 1981-2018 on 13 bird species from 76 sites, and 18 bat species from 53 sites, which included about 11,000 birds and bats. This research confirmed that males prefer cooler temperatures compared to females, and at certain times, the sexes separate from each other comletely.
Since this pattern can be observed in so many different species, Levin suggested that males and females have different heat-sensing mechanisms, and that neural mechanisms and hormones may be affecting the sensations in the sexes. However, the study did not identify any of those mechanisms specifically.
Dr. Magory Cohen suggested that if males and females are separated, there is less competition for resources. Potentially aggressive males are also kept away from vulnerable babies. Females may also be producing offspring before they can effectively regulate their own body temperatures, leading them to warmer places.
"The bottom line is, going back to the human realm, we can say that this difference in thermal sensation did not come about so that we could argue with our partners over the air conditioning, but rather the opposite: it is meant to make the couple take some distance from each other so that each individual can enjoy some peace and quiet," suggested Levin and Cohen.