Extreme longevity may be the rule not the exception in Balaenid whales

We fit ongoing 40+ year mark-recapture databases from the thriving southern right whale (SRW); Eubalaena australis, and highly endangered North Atlantic right whale (NARW); Eubalaena glacialis, to candidate survival models to estimate their lifespans. The median lifespan for SRW was 73.4 years, with 10% of individuals surviving past 131.8 years. NARW lifespans were likely anthropogenically shortened, with a median lifespan of just 22.3 years, and 10% of individuals living past 47.2 years. In the context of extreme longevity recently documented in other whale species, we suggest all balaenid and perhaps most great whales have an unrecognized potential for great longevity that has been masked by the demographic disruptions of industrial whaling. This unrecognized longevity has considerable implications for the basic biology and conservation of whales.,

Mark-Resight Data. From 1979 to 2021, SRW were annually surveyed in October by helicopter between Nature’s Valley and Muizenberg, False Bay along the south coast of South Africa. All individuals sighted were noted, and callosity patterns of females with calves were carefully photographed for identification purposes. Photos were compared to a long-running photo-identification catalog and matched. Over the 42-year period, this resulted in a mark-recapture data set of 2476 unique females, of which 139 have known birth years. Survey methods and photo identification details are available in (1) and (2).
Mark-recapture records for NARW spanned approximately the same period. Starting in the mid-1970s a photographic catalog of all NARWs began, and the observation effort intensified and became more organized in the 1980s. Unlike the SRW mark-recapture data, observations for NARW are assembled by a large group of collaborating scientists working across the species’ entire range. The photograph..., , # Extreme longevity may be the rule not the exception in Balaenid whales

[https://doi.org/10.5061/dryad.np5hqc01m](https://doi.org/10.5061/dryad.np5hqc01m)

The data contains annual sightings (0: not observed that year; or 1: observed that year) for uniquely marked right whales. Sighting records are as early as 1936 to the present, but most observations were made after 1975.

## Description of the data and file structure

Each row contains the sightings history for a unique whale.

Column 1 \"ID\" contains the whale ID

Column 2 \"Birth\": Year of birth, if known. If unknown, contains a 0.

Column 3 \"Death\": Year of death, if known. If unknown, contains a 0.

All remaining columns: Observations years. Contains a 1 if the animal in that row was seen, contains a 0 if the animal in that row was not seen.

## Sharing/Access information

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## Code/Software

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