The Loss of a Matriarch

In modern times, when a beloved celebrity dies, there is an outpouring of grief on social media; the public expresses their gratitude for the individual’s contribution to art and society and recalls their personal connections and experiences with them.  In the scientific community, a similar outpouring occurred with the death of J2, known fondly by many as Granny.  Granny was the matriarch of the endangered Southern Resident Killer whales and local celebrity among researchers, whale-watchers, and animal lovers.  She was the most famous of all southern residents, not just due to her impressive age and stature, but because of her position as the matriarch of J pod.  Her passing marks the latest in a series of deaths for the J Pod this year, prompting researchers to worry about the future of the Southern Resident Killer Whale population.

Ken Balcombe, the Senior Scientist at the Centre for Whale Research in Washington, announced her death in December after she had not been seen since mid-October.  Granny was estimated to be 105 years old at the time of her death, making her the oldest known killer whale.  Aerial photogrammetry studies conducted by NOAA Fisheries and the Vancouver Aquarium estimated her length to be 21 feet, which is above average for an adult female.  Her impressive size is thought to be an indication of greater food availability in the past, when the southern resident’s preferred prey-chinook salmon-were more abundant.

Photographs taken of J2 in September, however, show her to be in poor body condition.  These last photographs of J2 show her catching and sharing fish with a motherless youngster, J45, and highlight the unique social structure of these animals.  A paper published in Science in 2012 found that older orca females play a crucial role in the survival of their adult sons.  Sons who lose their mothers are more three times as likely to die as well.  This finding suggests that the knowledge and support of older females are driving factors in the adaptation toward long lifespans.  Female killer whales have evolved to live decades beyond their reproductive age because it is beneficial to the rest of the pod, an adaptive trait that is rarely seen in nature.  Post-reproductive females act as matriarchs to younger animals, and are essential to the cohesion and survival of their pod.  Researchers believe that they pass down vital knowledge, such as the location of foraging areas and hunting strategies, gained through decades of experience.

This matriarchal knowledge is especially beneficial to the pod in times of food scarcity, and the death of J2 has researchers concerned for the status of the rest of J Pod, who are already threatened by the decline in their main food source.  Chinook salmon makes up 80% of the diet of killer whales, but chinook numbers have dropped to a mere 10% of historical levels.  J2’s death follows that of four other whales from J Pod this year, leaving only 78 Southern Residents.  J34 was found dead near Sechelt after a member of the public found the body washed up on shore and called the Marine Mammal Response Network.  The cause of death was determined to be blunt force trauma from a vessel strike.   J28 and her calf also died in October, after reports showed her deteriorating body condition.   These recent deaths highlight the concern for the impact of limited food resources and vessel disturbance and has prompted public action; there has been a call for the breaching of four hydroelectric dams on the lower Snake River to restore chinook salmon stocks and a proposal for a whale protection zone on the west side of San Juan Island to minimize vessel disturbance.

There is no doubt that the death of Granny (J2) will spur on the efforts of researchers and activists to save her remaining family members.  She leaves behind a legacy of many decades of data that will benefit ongoing research and help to save the Southern Resident killer whale population from extinction.

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