A blog about some of the Antarctica Weddell seal population study field research work and outreach efforts during the Weddell seal pupping season in the Erebus Bay region of Antarctica's Ross Sea. Weddell seal images and recordings obtained under NMFS Permit Nos. 1032-1917, 17236, and 21158. More information at http://WeddellSealScience.com
In Part Four of our longer project documentary "How Moms Matter To Weddell Seal Pups" the focus is on what project scientists are learning about Weddell pup birth timing during the pupping season. Are pups better off if they're born in the early part of the season, late in the season, or somewhere in the middle? How do differences in Weddell moms affect the time in the season when the pup is likely to be born? Turns out that the time during the season when a pup is born, and the age and experience of that pup's mom, can affect the pup's likelihood of survival to adulthood to have a pup of her own.
Weddell seals have developed many different fascinating adaptations for living and thriving in the cold icy environment of Antarctica. For example, they have evolved large strong sharp front teeth to use to rake the sea ice to enlarge and keep holes and cracks open so they can breath and access the surface of the sea ice. They also have developed the ability to hold their breath for over an hour to make long dives beneath the Antarctic sea ice.
These seals also have a special secret to getting around when they're on top of the sea ice! Here's the Weddell Seal Population Project's latest short-short video produced by Jeremy Schmidt that shows us how it's done!
In keeping with the challenging sea ice conditions this season around McMurdo Station and the Weddell seal population study area of Erebus Bay, the project’s remote sea ice camp is now being pulled a few weeks earlier than in previous recent seasons. Reports lead scientist Jay Rotella, "We have had a very good year for pup production and other data collection." Sea ice camp this season had been placed at Turtle Rock nearer McMurdo due to this year's challenging sea ice conditions. Turtle Rock is located a good distance from some of the more remote pupping colonies the field team must access in the Erebus Bay study area to do their science work. For over a decade, camp has been placed at Big Razorback Island, further out in the study area and more central to many of the pupping colonies.
HDR photo of the study's Kitchen Hut at Big Razorback Island in 2010
The sea ice this season is thinner in places and can be more troublesome for heavy equipment now. Yet the field research team’s work gathering data on the seals throughout the study area continues! This work keeps intact a multi-generational Weddell seal database unique in the scientific community, and is made possible by the many hard hours put in by the field team and the dedicated assistance of many different groups and support personnel on the Ice.
There are a few later-season pup births still taking place, and numerous pups and moms that the research team must continue to follow until the nursing period is over. The field team will work from McMurdo Station now to continue to get into the field as safely and successfully as they are able to gather necessary data.
In Part 3 of our project’s longer video, “How Moms Matter To Weddell Pups”, the presentation focuses on what the scientists are learning about how differences among Weddell moms and pups may effect the pup's survival to adulthood. And particularly when it comes to when during the pupping season the pups are born, how much they weigh at birth, and then how much at weaning. It will be interesting to learn if and how the challenging sea ice conditions this season affect the survival to adulthood of this year’s cohort of pups!
The Antarctica Weddell seal population study's remote sea ice camp is at Turtle Rock this year due in part to the sea ice conditions this season. Peak Weddell pupping season is now winding down. New pups will continue to be born for some time, but not at nearly the rate of peak season. Lead project scientist Montana State University professor Jay Rotellareports, "we don’t have internet [at our sea ice camp] and have been able to work each day without weather delays." While this has limited internet updates on the season as it has progressed, it has also allowed the field team to take full advantage of peak pupping time to get a lot of work done!
Since our last report from the ice, the field team has been able to get out into the field without substantial weather delays and put a lot of effort into finding and working with the seals in the Erebus Bay study area. Notes Rotella in his new update, "It looks to be another big year for pup production with over 500 pups [born] so far this year. It’s also a great year for getting data on time spent in water by pups and on weight gain and loss by pups and their mothers."
Here's an award winning project short video documentary that presents information on work done by the project on assessing Weddell seal pup time spent in the water. As scientists learn more every year about which pups actually survive to return as adults to have pups of their own, researchers will be able to better understand the relationship between pup time spent in the water learning to swim and other Weddell seal life skills, and Weddell pup survival to return as reproducing adults.
For viewers interested in watching stereo 3D videos, here's an award-winning project stereoscopic short documentary video on Weddell pup swimming behavior and survival. You'll need 3D glasses to get the stereoscopic effect...
The Erebus Bay Antarctica Weddell seal pupping season is now at its peak. The field research team is currently working to find all the Weddell pups born in the study area to identify, tag, and add them to the over 50 year population database. The team is weighing a select group of pups and moms to determine their current weights, and measuring the time select pups spend in the water during the approximately month and a half long nursing period.
The field researchers must travel to all the different Weddell pupping colonies in the Erebus Bay study area to do their jobs. Their travel is usually by snowmobile. This season the sea ice has been interesting and a bit challenging, yet the field team carries on during what is a very busy Weddell pupping season! We'll update you with new pup numbers as soon as field team members can access the internet.
The project scientists are gathering data to learn the extent of differences--variation--among Weddell moms and pups. As more is learned about variation in these Weddell moms and pups, the scientists are able to gather data about how many pups with particular characteristics survive to adulthood to have pups of their own. Researchers can follow the generations of pups born to particular moms, and are assessing the contributions to the population of surviving pups. The scientists are thus able to learn more about which individual characteristics have significant effects on pup survival to reproduction.
In the following Part 2 segment from our latest project documentary, "How Moms Matter To Weddell Pups", the topic of Weddell seal variation is introduced. Subsequent segments from this original 14 minute project documentary highlight the effects that such differences among Weddell moms and pups can have as to whether a pup will survive to adulthood and reproduction, and which of those moms are so successful that they have numerous pups, some of which go on to also become very successful moms...Weddell seal super moms!
Below, is an earlier project documentary on Weddell seal variation, "Being Different if You're a Weddell Seal in Antarctica". This previous documentary goes into some detail about the kinds of variation among Weddell seals that the scientists are finding. The new documentary, "How Moms Matter To Weddell Pups", takes everything a step further by presenting some of what the scientists have learned to date about the effects on pup survival of particular characteristics among Weddell moms and pups. Here is that full video for a bit of background:
Weddell seal pups spend around 6 weeks after birth with their moms nursing, gaining a lot of weight, learning to get in and out of the cold Antarctic water, learning to swim well, and learning about how best to survive to adulthood by watching their moms interact with other seals in the pupping colonies. Then at around 45 days, Weddell moms leave their pups to fend for themselves with what they've learned during the nursing period. Only some 20% of female Weddell pups will survive to adulthood to have pups of their own. Here's the latest short-short Weddell Seal Science project video by Jeremy Schmidt on "Pup Life Lessons":
It's peak Weddell seal pupping season around the pupping colonies in Erebus Bay, Antarctica right now. The Weddell seal population study field team is extremely busy finding, recording, and tagging all the new pups born in the study area. Field researchers are also busy determining how much time a selection of Weddell pups spends in the water during this first 45 days of life. The field team works throughout the pupping season to determine the mass (weight) of a select group of moms and pups with known ancestries. These pups will be weighed three times during the nursing season, once near birth, and then again at the mid-nursing period, and finally at 45 days near the very end of the nursing season right before their moms leave them to survive on their own. The scientists have learned that there is wide variation among Weddell pups in all these areas, including how old and experienced their moms are, at what point during the pupping season they are born, weight at birth, weight gained during the nursing period, and time spent in the water learning to swim well. These individual characteristics, the scientists are learning, affect the Weddell pups' chances of becoming one of those 20% of female pups to survive to adulthood and have pups of their own.