Report From The Field By Dr. Jay Rotella On Record-Setting Old Weddell Mom And 23rd Pup:
The team documented a record-tying and record-setting female Weddell seal this week. A Weddell seal mother wearing blue tags with the numbers 0550 on them (we refer to her as 0550C - “C” denotes the tag color, it's “C” for cerulean), was sighted at the Hutton Cliffs colony with a newborn pup. While tagging her pup and recording the information on the pup and mom, our field computer let us know that the mom is 32-years old and has had 22 pups in previous years.
Photo by Parker Levinson of record-setting oldest Weddell Seal SuperMom with her 23rd pup.
Such numbers are so rare to see that we looked up the full details on this mom at the end of the day on a computer with the full database for all the marking and resighting data that have been collected on almost 30,000 seals from 1978 to present. What we learned is that 0550C ties the record for the longest known lifespan: only 1 other seal (also a female with a pup) is known to have survived to 32 years of age even though thousands were tagged long enough ago to have had the chance. And by giving birth to her 23rd pup in 2022, she sets a new record for the number of pups produced by a single female in a lifetime.
Photo by Parker Levinson of record-setting oldest Weddell Seal SuperMom with her 23rd pup.
Earlier researchers on the project tagged 0550C in 1990 at the Turtle Rock colony. She was next sighted as a pre-breeder when she was 5-years old at Turtle Rock quite close to where she was born. She returned to Turtle Rock again the next year and produced her first pup at age 6, which is a year or 2 younger than what’s typical for age at first reproduction. At 7 years of age, she produced a pup at Turks Head, which is about 5 miles away in a straight line. Since then, she has typically given birth to a pup at Hutton Cliffs and done so in every year.
Map of annual locations of new Weddell SuperMom prepared using Quantarctica by Dr. Jay Rotella.
In fact, she has produced a pup in 23 of the last 27 years. Further, she has been sighted multiple times during every pupping season from 1995 through 2022. The accompanying map, which was produced in Quantarctica, shows her annual locations. The number next to each colored dot indicates her age when she was at that location. The color of a dot indicates her breeding state: pink is for years when she did not produce a pup (i.e., when she was a pup, a pre-breeder, or was skipping reproduction), red indicates where she was when she was a 1st-time mom, and green is where she was when she was an experienced mother. Many of the dots are on top of one another because her pupping locations have been in such similar spots and the dots are on top of one another for quite a few years.
Photo by Parker Levinson of new Weddell SuperMom showing worn teeth.
Our field crew leader, Parker Levinson, patiently photographed the mom and her pup with a telephoto lens, above. Based on seeing the mom and her pup in the field and reviewing the photos, her pup looks very healthy, and 0550C looks generally healthy as well. But she definitely shows some signs of aging. Notably, her left eye is a bit cloudy and has a growth in the corner of the eye. And, her upper canine and outer incisor teeth show quite a bit of wear, which is not surprisingly given that mothers gnaw the ice with their teeth to open breathing holes and to make nice smooth ramps that make it easier for young pups to exit from the water after swimming when just a couple of weeks old. However, we didn’t see any evidence of any abscess or fractured teeth, both of which were reported in Weddell seals, in a 1969 paper that Ian Stirling wrote about tooth wear in the species.
Photo by Parker Levinson of record-setting oldest Weddell Seal SuperMom with her 23rd pup.
We are interested in looking up how many of her daughters and sons have shown up again since being born and if any of her daughters have been seen with pups. Perhaps some of them might be strong reproducers as well. Perhaps she will return again in 2023 and other future years and produce even more pups. Of course, only time will tell. One has to be patient to learn about such females: 32 years is a pretty long time!
- Dr. Jay Rotella, Lead Scientist on the Weddell Seal Population Study
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