As we come to the
middle of the winter season the majority of the cows that are going to pup on
the Southeast Farallon Island (SEFI) this year have made it to the colony and pupped. Although
a few stragglers may still arrive some of the first cows that arrived back in
December have already weaned. Typically
northern elephant seals cows nurse their pups for about 24 days before
returning to the sea to make their way back to feeding grounds in the northern
Pacific Ocean. During this short time pups will gain 150-250 pounds or around
10 pounds a day! When their moms leave pups will be a hefty 300 pounds but they
need this large energy reserve to survive while they learn to swim and forage
for themselves.
Like mother like son
So far in the colony eight
pups have successfully weaned and are affectionately called "weaners". One of these weaners, “06”, is the daughter of
Venus. Venus arrived to SEFI on December 25th and had her
pup on December 28th. During a particularly stormy day in early
January Venus decided that the beach she and her pup were on was too exposed to
the large waves and made the unusual choice to move her pup to another beach.
This move turned out to be a good choice and she nursed her pup for 26 days
before leaving on January 23rd. To have successful
pups, cows not only have to pick a good pupping location, they also have to commit
a huge amount of energy to nursing. Northern elephant seals do not eat while
they are hauled out and cows will lose 500-700 pounds during the pupping
season.
Venus when she first
arrived (Stamped -06)
Venus and her pup “06”
after 3 weeks of nursing
“06” is one of our
first weaners of the season and has almost finished her first molt.
It has
been a challenging season for some of the other cows and pups of the in the
colony. Several pups have been lost due
to large swell events and others have been caught in the crossfire between fighting
males. This has left some cows without pups but plenty of milk. This
circumstance has enabled some pups to become what are known as super weaners.
Super weaners (or double mother suckers) are pups that were weaned from their
moms but then continued nursing off of other cows. With all the extra milk
super weaners’ weight can reach upwards of 600 pounds. Check out the youtube video from the hit TV series "The Big Bang Theory" when they discusses super weaners: https://youtu.be/FaTfNiXHTCg?t=1m25s
Currently in the
colony we have two weaners that are on their way to becoming super weaners.
Shelly’s pup “03” and Jane’s pup “20” have both found new cows that lost their
own pups early in the season who are willing to nurse them. Weaner “20” was
nursed by his mom Jane for 26 days but after Jane left on February 4th
“20” was spotted nursing from cow Maddy. Maddy protects “20” like he was her
own and has been nursing him for a week already.
Weaner “20” nursing
from his new mom Maddy
The second super
weaner “03” was weaned around the same time as Venus’ pup “06” but has been
continuing to nurse from his new mom Frances for almost two weeks. “03” is
definitely the largest of all of the pups and weaners on the beach and is even
starting to rival some of the cows in size. Only time will tell if all the
extra nursing will give this King of the Pups a competitive advantage later in
life but hopefully he will return to SEFI in the future so we can
continue to follow his progress and see if he becomes King of the Beach.
Super weaner “03”
Written by 2016 SEFI
Winter Research Assistant Cassie Bednar
