Two Pregnant Orcas in Washington State’s J Pod
By Anna Michael
(Holly Fearnbach/SeaLife Response, Rehabilitation and Research SR3, and John Durban/Southall Environmental Associates)
Scientists believe that three orcas of Washington’s J Pod are pregnant. Aerial drone imaging showed photos of two orcas with protruding stomachs, shown above. The possibility of new orcas is especially exciting because of the endangered status of the species, with only seventy three Southern residents remaining.
The J pod consists of twenty four orcas that live off the coast of Washington state, and they can typically be spotted around San Juan Island. In orcas, pods consist of extended families of females and their offspring and have been found to contain up to four generations. The K and L pods are usually found in the same area. Together, the J, K, and L pods comprise the 73 members of the Southern Resident killer whales.
While locals and scientists are thrilled by the pregnancy news, they also have the responsibility of keeping the expecting mothers safe. Unfortunately, orcas have a high rate of failed pregnancy. Furthermore, it has been shown that our Southern Resident orcas have a lower fecundity rate compared to the orcas off the coasts of British Columbia and Alaska. Because of this, Washington has implemented policies to protect the pregnant orcas. For example, the state now requires vessels to stay 300 m away from pregnant or at risk orcas. This should benefit the pregnant orcas because noise from boats affects hunting success, and can even make an orca avoid eating it’s caught prey.
A study by the University of Washington revealed that Chinook salmon supply was the most significant factor affecting orca pregnancy success. Researchers used orca scat, or waste, for hormonal analysis and identification of sex and pod. The scat was identified by a program called Conservation Canines. Boats followed orca pods, and the dogs were trained to sniff and detect orca scat from the bow of the boat. After collection, researchers analyzed levels of four key hormones: progesterone, testosterone, glucocorticoid, and thyroid hormone. The progesterone and testosterone levels in the scat demonstrate the orca’s reproductive status. Glucocorticoid and thyroid hormone are both signs of stress, and the levels reveal whether the stressor is nutritional, or external like boat traffic. After sample analysis, scientists found hormonal signs of nutritional stress as an upwards trend over the previous seven years (2010-2017). Pregnant orcas increase food intake by 25% at the end of pregnancy, so it is imperative that they have access to a decent Chinook salmon supply as well as appropriate hunting conditions.