Super weaner
A super weaner (also super-weaner or superweaner) is an exceptionally large elephant seal at weaning age. Super weaners may reach their large sizes by stealing milk from nursing female elephant seals or by being adopted by an additional mother elephant seal.
Background
[edit]Elephant seals have an abrupt weaning process, in which the weaned juvenile seal does not receive assistance from its parents in finding food. The postweaning period is important for the seals' development, with a high mortality rate.[1]
Phenomenon
[edit]A super weaner, an elephant seal at weaning age which obtains milk from multiple females, can weigh 600 pounds (270 kg). A typical elephant seal at the same age weighs between 250 pounds (110 kg) and 350 pounds (160 kg).[2] While most mother elephant seals will bite weaned elephant seals that attempt to suckle, some will allow it for unknown reasons;[3] some super weaners also obtain the additional milk through theft.[4]
Instances
[edit]
A study carried out on Año Nuevo Island in California between 1972 and 1977 observed the existence of some recently weaned northern elephant seal pups which either stole milk from nursing females or were "adopted by foster mothers." Male pups were more persistent and successful at stealing milk, and the largest weaners were universally male,[1] including exceptionally large weaners which the study defined as "superweaners". These seals were "so large that their corpulence impeded their movements"; observation of two of them showed that their ability to acquire additional milk after being weaned was a major factor in their size.[5] The study additionally found that the large weaner seals reach their large sizes through two distinct strategies: by stealing milk from nursing female elephant seals ("milk thieves"),[4] or by being adopted by an additional mother elephant seal ("double mother-sucklers").[6]
A 2014 study published in Proceedings of the Royal Society B explored the benefits of high fat stores in female northern elephant seals, which relate to their buoyancy.[7][8] Daniel P. Costa, one of the authors, later stated that the findings might explain a known phenomenon in which super weaners are rarely seen again after departing the rookery. Costa suggested that super weaners are likely so buoyant that they have difficulty figuring out how to feed.[8]
A 2021 study, also in Proceedings of the Royal Society B, removed super weaners from modeling analyses because it utilized "the assumption that a single mother nursed a single pup throughout the average lactation period". Super weaners were defined as weaners weighing more than 170 kilograms (370 lb).[9] This study found that both male and female pups can become super weaners, although they are more likely to be male (64% of 94 super weaners measured).[9]
In popular culture
[edit]In "The Maternal Combustion", a 2015 episode of The Big Bang Theory, Leonard Hofstadter compares Sheldon Cooper to an elephant seal pup who steals milk because Hofstadter feels Cooper is getting all the attention from Hofstadter's mother in addition to his own. Cooper replies that because both mothers are seeking to give him their attention, he is not a super-weaner, but rather a double mother suckler.[10]
References
[edit]Citations
[edit]- ^ a b Reiter, Stinson & Le Boeuf 1978, p. 338.
- ^ California State Parks.
- ^ Black 2015.
- ^ a b Reiter, Stinson & Le Boeuf 1978, p. 344.
- ^ Reiter, Stinson & Le Boeuf 1978, p. 350.
- ^ Reiter, Stinson & Le Boeuf 1978, p. 347.
- ^ Adachi et al. 2014, p. 1.
- ^ a b Stephens 2014.
- ^ a b Holser et al. 2021, p. 3.
- ^ Ray 2015.
Works cited
[edit]- "Elephant Seals". California State Parks. Retrieved 2021-11-25.
- Adachi, Taiki; Maresh, Jennifer L.; Robinson, Patrick W.; Peterson, Sarah H.; Costa, Daniel P.; Naito, Yasuhiko; Watanabe, Yuuki Y.; Takahashi, Akinori (2014-12-22). "The foraging benefits of being fat in a highly migratory marine mammal". Proceedings of the Royal Society B: Biological Sciences. 281 (1797): 20142120. doi:10.1098/rspb.2014.2120. ISSN 0962-8452. PMC 4241001. PMID 25377461.
- Black, Riley (2015-01-12). "Science Word of the Day: Super-weaner". National Geographic. Archived from the original on May 7, 2021. Retrieved 2021-11-25.
- Holser, Rachel R.; Crocker, Daniel E.; Robinson, Patrick W.; Condit, Richard; Costa, Daniel P. (2021-10-13). "Density-dependent effects on reproductive output in a capital breeding carnivore, the northern elephant seal (Mirounga angustirostris)". Proceedings of the Royal Society B: Biological Sciences. 288 (1960): 20211258. doi:10.1098/rspb.2021.1258. ISSN 0962-8452. PMC 8511744. PMID 34641731.
- Ray, Lincee (May 1, 2015). "'The Big Bang Theory' recap: 'The Maternal Combustion'". Entertainment Weekly. Retrieved 2021-11-25.
- Reiter, Joanne; Stinson, Nell Lee; Le Boeuf, Burney J. (1978). "Northern Elephant Seal Development: The Transition from Weaning to Nutritional Independence". Behavioral Ecology and Sociobiology. 3 (4): 337–367. doi:10.1007/BF00303199. ISSN 0340-5443. JSTOR 4599180. S2CID 13370085.
- Stephens, Tim (November 5, 2014). "Study shows benefits of being fat (but not too fat) for deep-diving elephant seals". UC Santa Cruz News. UC Santa Cruz. Retrieved 2021-11-25.