The scientists aren’t recommending intervention, even if the perpetrators tend to be the same few individuals. “We don’t know how natural it is,” says Ursula Siebert, a veterinary pathologist specializing in wildlife population health at the University of Veterinary Medicine Hannover who was not involved with the work. “It can definitely be hard to watch,” Langley adds. “But the life of a seal—and indeed any wild animal—is tough.”

Brood reduction isn't common in grebes, but I saw it anyway, and thought maybe I didn't get the straight dope from Disney movies growing up.

Wonder if the male killer is of the same bloodline? Lions often opportunistically kill offspring of other males to reduce competition for their own offspring and to bring females into estrous.

EDIT: FWIW I asked claude and it says

> Gray seals have a promiscuous, harem-based mating system, but paternity is diffuse and males don't guard specific females long-term the way lions do. A bull has little way of "knowing" which pups are his rivals' offspring vs. his own.

So seems unlikely (according to claude).