Upside-Down Whales May Be Moms Needing a Break from Nursing

Mothers of southern right whales occasionally float in an inverted position, a behavior that scientists suggest might help them conserve energy and limit nursing. A study released on July 6 in Mammalian Biology examined 75 hours of drone footage featuring 59 pairs of mothers and calves at Head of Bight, South Australia. The findings revealed that mothers rested 33% of the time, whereas calves rested only 13%. Approximately 25% of mothers were observed floating upside-down, a behavior noted 19% of the time, particularly during lactation. This may hinder calf feeding and relates to the energy demands of reproduction. Since the 1980s, the population of southern right whales has rebounded to between 12,000 and 15,000 individuals, prompting researchers to advocate for enhanced protections in calving areas, such as vessel exclusion zones.