Day In The Life: Skinny Females!

Molly McCormley at UC Santa Cruz Long Marine Lab, CA--As the females nurse their pups, they slowly become skinner and skinner until they look like a completely different seal! Females loose about 35 percent of their body weight during the breeding season! These are the skinny females! 

 

 

This is a skinny female on the beach at Año Nuevo State Reserve.  Notice how much smaller she is than the female behind her and how much bigger her pup is!  Her pup will be weaned in the next couple of days.  Photo: Molly McCormley

 

After being on the beach for a month fasting AND nursing a very hungry pup, females are itching to get back out into the open ocean so they gain back their coveted blubber layer.  Before they leave the beaches, females must mate so that they can give birth next year.

Not only is the alpha male looking to mate, but there are at least 3, possibly more, beta and loser males who are waiting for their chance, too.  As a female prepares to leave, whatever male is closest (alpha or beta) will normally mate with her. If there aren’t other males threatening his harem, he may escort her to the ocean. However, there are a lot of males out there, and alphas don’t often vacate their harems willingly!  If a female is left to cross the beach solo, the other males will fight for their chance to mate.  The males even go as far as to swim after her sometimes, though they usually give up the chase way before the female makes it out past the waves!

 

A male is attempting to mate with a female.  This particular male however was a beta and was chased away a few seconds later!  photo: Molly McCormley

 

 

As these skinny females head out to the open ocean, they leave behind their pup! Their pup, now a weaner, is left to fend for itself.  No more parental care will take place.  Females now focus on their long migrations, getting big and fat, and avoiding predators.

 

Today, skinny northern elephant seal females are embarking on their first of two annual migrations, the 70 day foraging trip up to the North Pacific Transition Zone. To of our own elephant seals, Poppy and Ellie, are still transmitting and can be seen traveling out to the transition zone.  Soon, they will return, molt off their fur, and then leave for their 7 month journey to sea. Females will travel all the way up into the northern pacific ocean after the molt, which can be around an 8,000 mile journey round trip.  This means that they are swimming about 4,000 miles out and back! That’s a long journey!

This is a harem that the females live in while on the beach.  Notice the alpha male close to the group while a beta is farther away, hoping for a chnace to mate.  If you look at the group you can tell how close the females are to leaving by how skinny they are!  Photo: Ashley Pearson

 

 

This is a shot of a skinny satellite tagged female (G1261) just after she weaned her pup! She's ready to head out to sea! Photo: Nicole Teutschel

 

 

 Stay tuned for more Day in the Life blogs! If you’d like to learn more check out the E Seal species page and the Elephant Seal Homcoming Days Page!