March 24th - Deceased Dolphin Calf in Seabrook Island
Warning: This post talks about a deceased calf and grief and may be hard for more sensitive readers (& us at LMMN)
On March 24th, our team was notified about a (presumed) mom pushing her dead calf in Seabrook Island, SC. This mom and calf pair were reportedly seen across the past few days in the same location and by the level of decomposition in the calf, it was likely this mom had been pushing her dead calf for several days already. Because the mothers will stop eating during this time, reducing her own health, a response was initiated to attempt to safely pick up the calf and allow the mom to move on.
Team members, Nicole and Lauren, and help from folks with the St. John's Kayak Tours, found the pair and after observing mom's behavior for several minutes, slowly approached with a boat. The mom left the calf, dove down, and was not seen again. The calf was safely retrieved and brought back to the lab for necropsy. Based on unhealed umbilicus, folded dorsal fin, and fetal folds, this was likely a stillborn fetus
In the field of marine mammal biology, this is termed "epimeletic behavior", which typically involves stationing near the carcass or actively carrying it on the dorsum or melon, lifting it above the surface, holding it in the mouth, bringing it to the surface when it sinks, taking it underwater during dives, and sometimes vigorous strikes (Reggente et al., 2016).
This behavior has been related to mourning and grieving and may be intended to contribute to the recovery of individuals that only appear to be dead, with an unknown potential for rescuing an offspring or companion. These animals also have strong social bonds that provide motivation to rescue and an unwillingness to leave the dead that may lead to epimeletic behavior lasting beyond reasonable hopes of success.
One of the most well-known cases of a marine mammal exhibiting this behavior was in 2018 with a killer whale, named Tahlequah (Southern Resident, J35). People from all around the world watched as she carried her dead calf for 17 days over 1,000 miles.
It is heartbreaking for all to witness these animals grieve, but it is a clear reminder of the intelligence and sociality of these animals. It is also a reminder that we need to do our part in creating a healthier environment and ecosystem to help protect these animals and increase survival rates.
Source: Reggente, M.A., Alves, F., Nicolau, C., Freitas, L., Cagnazzi, D., Baird, R.W., and Galli, P. (2016). Nurturant behavior toward dead consepecifics in free-ranging mammals: New records for odontocetes and a general review. Journal of Mammalogy, 89.