It’s not a good time to be a polar bear. Climate change threatening their natural habitat and lifestyle is just one of the major concerns facing this endangered species—now, scientists uncovered a link between their exposure to pollutants and a weakening in their penile bone. This obviously can cause some issues in the mating habits of the bears.
The research by a team at Aarhus University in Denmark discovered this correlation after studying penile bone specimens, known as baculum, from 279 polar bears from Greenland and Canada. Baculum—a bone lacked by human males, but found in other mammals like raccoons, bats, and mice—essentially works to aid the penis during reproduction.
In their study, scientists measured exposure to polychlorinated biphenyls (PCBs), a pollutant that is known to accumulate in Arctic areas, and low baculum bone density in polar bears. The baculum is apparently quite easy to acquire, as they’re often kept by hunters as a symbol of their score. While they can’t directly slap a cause-and-effect label on PCBs and weak polar bear penises, the researchers note previous studies have proven other pollutants have also led to smaller penis and testes sizes in the bears.
The researchers hypothesize that lower bone density in the baculum can lead to… well, breakage during copulation.
They also think climate change—which most directly affects the food supply the polar bears are dependent on—is being amplified by these high levels of pollutants, making this an excessively tough environment for the animals to survive.