Seals engage in social distancing, probably to prevent diseases

Seals practice social distancing much like humans did during the Covid-19 pandemic, possibly as a disease prevention mechanism. This insight comes from a study conducted by the Royal Netherlands Institute for Sea Research (NIOZ), Wageningen University & Research (WUR), and Swiss Federal Institute of Technology Lausanne (EPFL), NH Nieuws reported.

The Dutch Wadden Sea is home to two species of pinnipeds: the grey seal and the harbor seal. Both species were heavily hunted in the past but have since rebounded. Current counts estimate around 6,500 grey seals and nearly 8,000 harbor seals. Grey seals are larger, with males measuring up to 3 meters and weighing 350 kg, while harbor seals reach lengths of 1.6 meters and weight approximately 87 kg.

Through aerial images of the Wadden region, scientists measured the distance between seals and their immediate neighbors. The findings suggest that harbor seals maintain greater distances than gray seals.

#Seals 🦭↔️| Social distancing with seals? Researchers investigate: "By measuring the distance of every seal to its neighbours, we found that harbour seals stay at larger distances from conspecifics than grey seals do", says Anne Grundlehner @WURmarine. https://t.co/kXTYLKc51T pic.twitter.com/kh5R2HEgBj

— Wageningen U&R (@WUR) August 9, 2023

Jeroen Hoekendijk, one of the researchers, indicated that this behavior might stem from the harbor seal's higher susceptibility to diseases. Between 1988 and 2002, the Wadden region experienced two notable outbreaks of the Phocine Distemper Virus (PDV). During these periods, nearly half of the harbor seal population died, in stark contrast to the gray seals, which were largely unaffected, according to the researcher.

By maintaining distance, the spread of diseases becomes more difficult. This is similar to the social distancing humans practiced during the pandemic.

However, it would be wrong to believe these animals remember the outbreaks and thus maintain distances. "It's not about memory. It might be an evolutionary adaptation where those who keep more distance are less likely to fall sick," Hoekendijk pointed out.

Hoekendijk was surprised by the results. "We had a suspicion that the harbor seal keeps its distance from its peers, but the fact that they actually practice social distancing is a surprise."