One of the big questions I had for the Weddell Project 2014 Antarctic field team was whether the very old Weddell mom with the study record number of pups had lived to return again to the Erebus Bay Study area, and whether she had a new pup this year. Per Weddell population study lead scientist Jay Rotella, the great news is that she has lived through another winter and returned--and she has given birth to her 22nd pup! This is a new Weddell population study record.
This is a very rare old Weddell mom. According to lead project scientist Jay Rotella, who is currently working in the field as part of the 2014 Antarctica field team, what is so remarkable about this Weddell mom is that she has had 22 total pups so far. She produced pups at ages 8, 9, 10, (3 in a row then 1 year off), 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, (16 in a row then 2 years off) 30, 31, and 32 (3 in a row for the 3 most recent years). Weddell seal moms live an average of 15 years, and usually have around 2 pups every 3 years, so this long life and frequency of pupping is very unusual.
All of the pups of SPENO 5970, as she's known in the database, were born at Hutton Cliffs. For the past several years Hutton Cliffs has been a rugged area with jumbled multi-year ice, hummocks, and rough sastrugi. This year the ice is smooth 1st year ice; and much of the seal colony can be seen for some distance on the flat terrain.
This rare old mom was born in 1983 at an area called the North Base of the Erebus Glacier Tongue. This area is relatively close to the Hutton Cliffs pupping colony, where all of this Weddell mom's 22 pups have been born over her reproductive life to date.
Because of the longterm dataset of the Weddell seal population project, the researchers are able to keep track of the Weddells in the study area and access data on over four decades of seals and several generations.
Working with the extensive database, lead population study scientist Jay Rotella was able to determine that of SPENO 5970's first 21 pups, 11 were females and 10 were males. "Of those offspring, 2 sons and 2 daughters have been seen again, which is right in line with what we'd expect based on other analyses indicating that roughly 20% of the seals make it to adulthood." Her new pup is a female.
Of SPENO 5970's surviving offspring, two daughters have returned to the pupping colonies to give birth themselves. One of those daughters is 23 years old and has produced 13 pups so far. One of that daughter's pups--a granddaughter of SPENO 5970--has gone on to have 5 pups herself.
Photo by lead scientist Bob Garrott of old mom in 2013 with her 21st pup showing the rugged terrain of Hutton Cliffs last year.
According to the database, Rotella notes that the old Weddell mom has at least 14 grandpups and 5 great grand-pups. We look forward to more photos of SPENO 5970 from the team this year as her 22nd pup gets bigger and bigger!
Photo by 2014 field team leader Terrill Paterson taken last year of old mom's 21st pup growing larger.
- Mary Lynn Price