Field Report From Prof. Jay Rotella:
We have a new record for the oldest Weddell seal ever recorded. Our new record-setter is 33 years old and with her 21st pup. She broke the longest-known lifespan record by 1 year, and she’s just 1 pup short of tying the record for the most pups produced in a lifetime, which is 22. She’s also a great reminder of just how faithful many of the animals in our study population are to the Erebus Bay colonies.
This female, who’s currently wearing yellow tags numbered 8281, has been documented in the study area in 32 different years starting with 1990, the year she was born and first tagged. She has been in the study area in every pupping season from 1995 through 2023. That’s 29 years in a row and includes 1995-1997, when she was a pre-breeder, 1998 when she had her first pup, 20 other years when she had subsequent pups, and 5 years when she skipped reproducing. She is also interesting in another way.
She has produced 14 sons and 7 daughters, which is obviously not a 50:50 sex ratio for offspring that’s the population-level average. We have found that the mothers who are more productive do tend to produce a greater proportion of sons.The idea behind that being that if you are in great shape and can produce a high-quality son, he can go on to sire many pups in this species in which the top males can breed with multiple females and in which females produce at most a single pup per year except in the very rare cases when twins are produced.
A map of her annual locations shows that she has been quite faithful to the Hutton Cliffs area, which is where we tend to see most, but not all, of the supermoms and something we plan to look into further in the next few years. Many of her annual locations are so close to one another that the markers on the map tend to fall on top of one another, which is why you don’t see all 29 locations on the map at the resolution of the image provided.
Comments