PAB is an acronym that seems neutral but hides one of the rarest and most tragic behaviors that can be observed in the animal kingdom. It actually stands for postmortem attentive behaviora definition which, in simple words, indicates all those behaviors of care and attention that are applied to a deceased loved one – usually a mother with a dead puppy.
PAB has been observed in many primates, in African elephants and also in giraffes, and now we must add an unexpected animal to the list: carnivorous, predatory, tending to be solitary. We are talking about leopard seals, protagonists of a study published on Polar Biology which documents several cases of PAB observed in Patagonia.
Mourning In mammals. PAB is a rare but not exceptional behavior, and has been observed in a fair number of land mammals: in addition to those mentioned above there are also dingoes and pigs. In marine mammals the behavior is less widespread, or rather less observed: it is no coincidence that those in which it is seen most frequently are large cetaceans (whales, dolphins and porpoises), which are carefully monitored and often filmed to document their behaviour.
The case of pinnipeds. PAB, however, is much rarer in pinnipeds (seals, sea lions and walruses): so far only six episodes in total have been documented. That’s why the photos and videos captured by the University of Rhode Island team are so exceptional: they document several episodes of PAB featuring female leopard seals caring for their dead pups for weeks at a time. One of these (particularly unlucky with little ones) has even repeated the gesture several times over the years, demonstrating that it is a well-rooted behavior and not a coincidence.
What is mourning for? Leopard seals are usually solitary animals, so watching mothers care for dead pups is doubly interesting. Also because the behavior itself does not, apparently, have any advantage, nor does it bring benefits to the animal: the authors of the study call it “maladaptive trait”, which is the opposite of “adaptive” – it is therefore a characteristic that only brings disadvantages.
This is why the team hopes, by continuing their observations, to understand what is behind the PAB in leopard seals: one hypothesis is that the behavior has a chemical origin, and is a sort of extreme reaction to the flood of hormones produced in the female’s body after giving birth.