With the cold season of the year, the battle for the right heating setting begins in many living rooms: Would you rather turn it up a bit to make it cozy and warm, or would it be better to save heating costs and defy the cold with an additional layer of clothing? However, the conflict goes beyond financial aspects, it also touches on questions of gender equality. As some studies have now found, women on average feel more comfortable than men at slightly higher temperatures. According to a Chinese survey, the difference in the comfortable temperature is around one degree Celsius – biologically speaking, conflicts on winter evenings are practically programmed.
However, the reason for the different temperature perception is largely unclear. The biologists Eran Levin and Tali Magory Cohen from Tel Aviv University have now approached the question from a rather unusual direction. They investigated whether there are different comfort temperatures in males and females in the animal kingdom – and thus possibly an evolutionary explanation.
Male bats stayed on a cool mountain, the females liked it warmer
The team found what they were looking for in birds and bats. The bat expert Levin noticed in previous studies that colonies divide into males and females, especially during the breeding season. While the male specimens can then be found on the cool Mount Hermon in northern Israel, the females are drawn to the warmer Sea of Galilee further south.
The team then systematically investigated the phenomenon: The researchers analyzed data from a total of 11,000 bats and migratory birds that had been collected over the past 40 years – for example, to provide the animals with rings for research purposes. Overall, the journal included Global Ecology and Biogeography published study with 13 species of migratory birds and 18 bat species. This enabled the biologists to measure certain temperature preferences in both bats and migratory birds. In general, the males were more likely to be found in cooler locations, while the females preferred warmer environments.
The fact that the differences exist in so many different species leads the researchers to suspect evolutionary reasons behind them. The different temperature sensations in males and females could therefore ensure that they avoid each other at certain times. Especially when offspring are born, the females need a lot of rest. The different comfort temperatures could naturally ensure that males go their own way at such sensitive times.
According to the scientists, birds and bats are well suited to researching different temperature perceptions, as they can react quickly to their environment – and simply fly to warmer places when they freeze. Gender-specific temperature preferences are also known in mammals. Male ibexes are drawn to higher, cooler altitudes than female ones during the day. Female dwarf lemurs prefer – in the presence of conspecifics – warmer environments, while male lemurs are more likely to be found alone in colder places.