Only 73 southern resident killer whales remain in the wild, and the species reproduces very slowly, making conservation efforts painstakingly slow. Fortunately, a pair of marine biologists with keen eyes spotted an encouraging sight in the waters off the coast of the Pacific Northwest. The biologists were observing killer whales in the Salish Sea when they noticed that three of the endangered whales are pregnant.

Killer whales, or orcas, give birth to one calf at a time, every three to ten years, so three pregnancies is an exciting event. The three whales had noticeable bulges below their rib cages, indicating pregnancy, but there is no way to know how far along they are in their 17-month gestation period.

Holly Fearnbach and John Durban, the biologists who made the discovery, were in the region using aerial drone technology to monitor the southern resident killer whale population. Killer whale social pods are categorized by their maternal ancestor. There are three in the Pacific Northwest: J, K, and L. The pregnant whales have been identified as J pod members J36, J37, and J19.

Threatened by food shortages, chemical pollution, and ships, the total southern resident killer whale population is at its lowest point since the 1970s. Unfortunately, the whales also have a high rate of miscarriage, so the researchers plan to continue to monitor the pregnancies closely.

Officials are asking all boaters to avoid the area if possible and urging them to follow Be Whale Wise regulations and stay at least 100 years away from marine animals.