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[By Greg Breed and Peter Corkerton]<\/em><\/p>\n Southern right whales\u00a0have lifespans that reach well past 100 years, and 10% may live past 130 years, according to our new research published\u00a0in the journal Science Advances. Some of these whales may live to 150. This lifespan is almost double the 70-80 years they are conventionally believed to live.<\/p>\n North Atlantic right whales\u00a0were also thought to have a maximum lifespan of\u00a0about 70 years. We found, however, that this\u00a0critically endangered\u00a0species\u2019 current average lifespan is only 22 years, and they rarely live past 50.<\/p>\n These two species are very closely related \u2013 only 25 years ago they were considered to be one species \u2013 so we\u2019d expect them to have similarly long lifespans. We attribute the stark difference in longevity in North Atlantic right whales to human-caused mortality, mostly from entanglements in fishing gear and ship strikes.<\/p>\n Survivorship curves show female right whales can live to very old ages, but humans are causing North Atlantic right whales to die well short of their potential. Plotted for comparison is the U.S. survivorship curve for women as estimated by the Social Security Adminstration.\u00a0Greg Breed<\/em><\/p>\n We made these new age estimates\u00a0using photo identification of individual female whales over several decades. Individual whales can be recognized year after year from photographs. When they die, they stop being photographically \u201cresighted\u201d and disappear. Using these photos, we developed what scientists call \u201csurvivorship curves\u201d by estimating the probability whales would disappear from the photographic record as they aged. From these survivorship curves, we could estimate maximum potential lifespans.<\/p>\n Twenty-five years ago, scientists working with Indigenous whale hunters in the Arctic showed that bowhead whales could live up to and\u00a0even over 200 years. Their evidence included finding stone harpoon points that hadn\u2019t been used since the mid-1800s embedded in the blubber of whales recently killed by traditional whalers. Analysis of proteins from the eyes of hunted whales provided further evidence of their long lifespan. Like right whales, before that analysis, researchers thought bowhead whales lived to about 80 years, and that humans were the mammals that lived the longest.<\/p>\n In the years following that report, scientists tried to figure out what was unique about bowhead whales that allowed them to live so long. But our new analysis of the longevity of two close relatives of bowheads shows that other whale species also have potentially extremely long lives.<\/p>\n Why it matters<\/em><\/strong><\/p>\n Understanding how long wild animals live has major implications for how to best protect them. Animals that have very long lifespans\u00a0usually reproduce extremely slowly\u00a0and can go many years between births. Baleen whales\u2019 life history \u2013 particularly the age when females start breeding and the interval between calves \u2013 is strongly influenced by their potential lifespan. Conservation and management strategies that do not plan accordingly will have a higher chance of failure. This is especially important given the expected impacts of climate disruption.<\/p>\n What still isn\u2019t known<\/em><\/strong><\/p>\n There are many other large whales, including blue, fin, sei, humpback, gray and sperm whales. Like bowhead and right whales, these were also\u00a0almost wiped out by whaling. Scientists currently assume they live about 80 or 90 years, but that\u2019s what we believed about bowhead and right whales until data proved they can live much longer.<\/p>\n How long can these other whale species live? Industrial whaling, which ended only in the 1960s, removed old whales from the world\u2019s whale populations. Though many whale populations are recovering in number, there hasn\u2019t been enough time for whales born after the end of industrial whaling to become old.<\/p>\n It\u2019s possible, even likely, that many other whale species will also prove to have long lifespans.<\/p>\n What other research is being done<\/em><\/strong><\/p>\n Other research finds the\u00a0loss of older individuals\u00a0from populations is a phenomenon occurring across most large animal species. It diminishes the reproductive potential of many species. Researchers also argue this represents a real loss of culture and wisdom in animals that degrades their potential for survival in the face of changing conditions.<\/p>\n What\u2019s next<\/em><\/strong><\/p>\n We want to better understand how whaling affected the number of old individuals in current whale populations and predict when the number of old individuals will recover to prewhaling levels. Preliminary results suggest it may be another 100 years before whale populations truly recover, even for species whose populations now number as many as there were before whaling.<\/p>\n For North Atlantic right whales, our research shows that even when the population was increasing, the management actions taken were insufficient to prevent these whales from dying far too young.<\/p>\n Greg Breed\u00a0Associate Professor of Quantitative Ecology at\u00a0University of Alaska Fairbanks.<\/em><\/p>\n Peter Corkeron is an\u00a0Adjunct Senior Research Fellow, Centre for Planetary Health and Food Security, Griffith University.<\/em><\/p>\n This article appears courtesy of The Conversation and may be found in its original form here<\/a>.\u00a0<\/em><\/p>\n \t![\"\"](\"https:\/\/i0.wp.com\/images.theconversation.com\/files\/638950\/original\/file-20241216-15-pxgw77.jpg?ssl=1\")
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