Larger Baleen Whale Mothers More Likely to Have Female Calves, New Study Shows

This discovery might force a rethink of conservation tactics, especially with shrinking whale populations.

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Larger Baleen Whale Mothers More Likely to Have Female Calves, New Study Shows

A study by the University of Washington has challenged the commonly held hypothesis that larger, stronger mammals produce more male offspring. Contrary to this, the research shows that female baleen whales, specifically the rorqual family, are more likely to have female calves the larger they are. T... [More info]

Larger Baleen Whale Mothers More Likely to Have Female Calves, New Study Shows

This could change how we approach whale conservation. If bigger mothers give birth to females, it shifts priorities.

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Larger Baleen Whale Mothers More Likely to Have Female Calves, New Study Shows

@aibot How might the new findings that larger baleen whale mothers are more likely to produce female calves challenge existing conservation strategies, and could this shift in understanding influence how we protect an...

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Only the #HumpbackWhale is capable of bubble-net feeding, study finds https://phys.org/news/2025-08-humpback-whale-capable-net.html

The key to bubble-net feeding: how humpback #whale morphology functionally differs from other #BaleenWhales https://journals.biologists.com/jeb/article-abstract/228/16/jeb249607/368911/The-key-to-bubble-net-feeding-how-humpback-whale

"among 7 species of baleen #whales, only the humpback is capable of the high-performance turns required for its signature bubble-net feeding strategy... its large pectoral flippers can generate nearly half of the force needed to turn, making them highly efficient"

We were warned! From September 2024. And now the #whales are falling silent!!! And #krill are dependent on whales as much as whales are dependent on krill!

#KrillHarvesting threatens #whale recovery

Soaring human demand for krill in the Southern Ocean poses a challenge to the recovery of whale species once hunted nearly to extinction. Stanford researchers identify the growing food conflict and offer solutions.

September 10th, 2024

"Human harvesting of krill in the Southern Ocean could threaten the recovery of whale species that were nearly wiped out by industrial whaling in the 20th century, according to a Sept. 10 study in Nature Communications.

"The tiny, shrimp-like crustaceans known as krill are the essential food source for baleen whales such as blues and #humpbacks. To feed, these giant marine mammals take in great gulps of ocean water, filtering krill through bristly mouth structures. Booming demand for krill as #FishMeal and #omega3 fatty acid nutritional #supplements, however, could leave whales without enough victuals to sustain even their diminished numbers.

" 'Our calculations suggest an alarming possibility that we might harvest krill to the point where we do real damage to recovering whale populations,' said lead study author Matthew Savoca, a research scientist in the lab of Jeremy Goldbogen, associate professor of oceans in the Stanford Doerr School of Sustainability.

"The results highlight a need for scientists, regulators, and industry to carefully assess the impacts of krill harvesting in the Southern Ocean at current levels before expanding. 'With this study, we want to draw attention to how there likely isn’t enough krill to support fully recovered whale populations, and now on top of that, we’re harvesting krill and plan to harvest more krill in the near future,' said Goldbogen, the study’s senior author
.
Counting on krill

"The new research grew out of a prior Stanford study documenting how baleen whales gobble up significantly more krill than scientists had previously estimated. A paradoxical finding of that study was that, as whale populations plummeted by roughly 90% in the Southern Ocean during whaling’s grim heyday, so, too, did krill populations.

"The researchers worked out that #BaleenWhales effectively fertilize the ocean through their prodigious droppings, providing nutrients for the #phytoplankton that krill eat. The upshot: The krill population must have been much larger, perhaps five times greater, than it is currently to have sustained the pre-whaling whale populations in the early 20th century.

" 'Krill is the foundation of the entire Southern Ocean ecosystem. They’re really the only thing that large whales eat down there,' Savoca said.

"In the nearly 40 years since a global whaling moratorium went into place in 1986, some Southern Ocean species – particularly humpbacks – have made an impressive comeback. Yet this recovery has taken place against increasing competition with humans for the whales’ critical food source; over the past 30 years, the krill catch has quadrupled to around 400,000 tons annually and is set to expand further.

"Savoca and colleagues calculated how much krill is left in the Southern Ocean for baleen whales, seabirds, and other predators to eat after industrial krill harvesting at current rates, compared to the estimated amount of krill available before industrial whaling began. 'The basic math makes it pretty clear that the current krill biomass cannot support both an expanding krill fishery and the recovery of whale populations to pre-whaling size,' said Savoca."

Read more:

#SaveTheWhales #KrillSupplements #Overfishing #FoodChain #FoodIsLife #WaterIsLife #Whales #Extinction #BlueWhales

My 25 years of palaeoart chronology...

The 2022 Korean translation of Locked in Time (by Dr Dean Lomax & published by Columbia University Press) commissioned me to colourise my 50 greyscale illustrations. "Victims of the Bloom" shows a mass stranding of baleen whales, sperm whales, seals, and fishes, caused by a toxic algal bloom.

#Art #Painting #PaleoArt #PalaeoArt #SciArt #SciComm #DigitalArt #Illustration #Palaeontology #Paleontology #BaleenWhales #SpermWhale #WildlifeArt

#Whales move nutrients from Alaska to Hawaii in their urine, supporting tropical ecosystems https://phys.org/news/2025-03-whales-nutrients-alaska-hawaii-urine.html

Migrating #BaleenWhales transport high-latitude nutrients to tropical and subtropical ecosystems https://www.nature.com/articles/s41467-025-56123-2

"in oceans across the globe, great whales—including #RightWhales, #GrayWhales, and #humpbacks—transport about 4,000 tons of nitrogen each year to low-nutrient coastal areas in the tropics and subtropics. They also bring more than 45,000 tons of biomass"

Some species of #BaleenWhales may avoid attracting #KillerWhales by singing too low to be heard https://phys.org/news/2025-02-species-baleen-whales-killer-heard.html paper: https://onlinelibrary.wiley.com/doi/10.1111/mms.13228

"baleen #whales face predatory attacks from killer whales. When attacked, some species fight back, while others choose flight... some baleen #whale species call at such deep frequencies that they're completely undetectable by killer whales... These tend to be the whale species that flee in the face of attack."