Baleen whales’ ancestry, new study


This video from Australia says about itself:

How suction feeding preceded filtering in baleen whale evolution

29 November 2016

A remarkable 25-million-year-old whale fossil called ‘Alfred’ has provided long-sought evidence of how whales evolved from having teeth to hair-like baleen – triggering their rise as the largest creatures on Earth.

From ScienceDaily:

Baleen whales’ ancestors were toothy suction feeders

May 11, 2017

Summary: Modern whales’ ancestors probably hunted and chased down prey, but somehow, those fish-eating hunters evolved into filter-feeding leviathans. An analysis of a 36.4-million-year-old whale fossil suggests that before baleen whales lost their teeth, they were suction feeders that most likely dove down and sucked prey into their mouths. The study also shows that whales most likely lost the hind limbs that stuck out from their bodies more recently than previously estimated.

Modern whales’ ancestors probably hunted and chased down prey, but somehow, those fish-eating hunters evolved into filter-feeding leviathans. An analysis of a 36.4-million-year-old whale fossil suggests that before baleen whales lost their teeth, they were suction feeders that most likely dove down and sucked prey into their large mouths. The study published on May 11 in Current Biology also shows that whales most likely lost the hind limbs that stuck out from their bodies more recently than previously estimated.

The specimen, which researchers unearthed in the Pisco Basin in southern Peru, is the oldest known member of the mysticete group, which includes the blue whale, the humpback whale, and the right whale. At 3.75-4 meters long, this late Eocene animal was smaller than any of its living relatives, but the most important difference was in the skull. Modern mysticetes have keratin fibers — called baleen — in place of teeth that allow them to trap and feed on tiny marine animals such as shrimp. However, the newly described whale has teeth, so the paleontologists dubbed it Mystacodon, meaning “toothed mysticete.”

“This find by our Peruvian colleague Mario Urbina fills a major gap in the history of the group, and it provides clues about the ecology of early mysticetes,” says paleontologist and study co-author Olivier Lambert of the Royal Belgian Institute of Natural Sciences. “For example, this early mysticete retains teeth, and from what we observed of its skull, we think that it displays an early specialization for suction feeding and maybe for bottom feeding.”

Mystacodon’s teeth exhibit a pattern of wear that differs from more archaic whales, the basilosaurids. Many basilosaurids were probably active hunters, similar to modern orcas, with mouths that were suited for biting and attacking, but Mystacodon has a mouth more suited for sucking in smaller animals, leading the researchers to conclude that Mystacodon most likely represents an intermediate step between raptorial and filter feeding and between the ancient basilosaurids and modern mysticetes.

“For a long time, Creationists took the evolution of whales as a favorite target to say that, ‘Well, you say that whales come from a terrestrial ancestor, but you can’t prove it. You can’t show the intermediary steps in this evolution,'” says Lambert. “And that was true, maybe thirty years ago. But now, with more teams working on the subject, we have a far more convincing scenario.”

Mystacodon bolsters that argument by displaying features of both basilosaurids and mysticetes. “It perfectly matches what we would have expected as an intermediary step between ancestral basilosaurids and more derived mysticetes,”says Lambert. “This nicely demonstrates the predictive power of the theory of evolution.”

Lambert and his colleagues think that Mystacodon may have started suction feeding in response to ecological changes. In illustrated reconstructions, Mystacodon is depicted diving down to the sea floor in a shallow cove, but based on this initial analysis, the researchers aren’t sure to which extent Mystacodon was adapted to bottom feeding. “We will look inside the bone to see if we can find some changes that may be correlated with this specialized behavior,” says Lambert. “Among marine mammals, when a slow-swimming animal is living close to the sea floor, generally the bone is much more compact, and this is something we want to test with these early mysticetes.”

The fossil’s pelvis offered another surprise: Mystacodon had fully articulated, tiny vestigial hind limbs that would have stuck out away from the whale’s body. Previously, paleontologists had thought that whales lost the hip articulation during the basilosaurid phase of their evolution, before baleen whales and modern toothed whales diverged. Though Mystacodon’s hind limbs were already tiny and well down the path toward being vestigial and useless, their articulation with the pelvis suggests that mysticetes and modern toothed whales may have lost this feature independently.

“For a long time, our comprehension of whale evolutionary history was hampered by the fact that most paleontologists were searching for bones relatively close to home, in Europe and North America,” Lambert says. “However, key steps in whales’ evolution happened in areas now occupied by India, Pakistan, Peru, and even Antarctica.” Lambert and his colleagues plan to return to the excavation site in Peru to see if they can find more whale fossils from different epochs.

See also here.

Humpback whale mothers whisper to calves to avoid predators


This video says about itself:

Baby Humpbacks Need 150 Gallons of Whale Milk a Day

4 February 2016

Whale milk is some of the richest milk available to any mammal. A baby whale will drink 150 gallons of it a day to sustain its dramatic growth.

From Functional Ecology:

High suckling rates and acoustic crypsis of humpback whale neonates maximise potential for mother–calf energy transfer

Summary

1. The migration of humpback whales to and from their breeding grounds results in a short, critical time period during which neonatal calves must acquire sufficient energy via suckling from their fasting mothers to survive the long return journey.
2. Understanding neonate suckling behaviour is critical for understanding the energetics and evolution of humpback whale migratory behaviour and for informing conservation efforts, but despite its importance, very little is known about the details, rate and behavioural context of this critical energy transfer.
3. To address this pertinent data gap on calf suckling behaviour, we deployed multi-sensor Dtags on eight humpback whale calves and two mothers allowing us to analyse detailed suckling and acoustic behaviour for a total of 68-8h.
4. Suckling dives were performed 20-7 7% of the total tagging time with the mothers either resting at the surface or at depth with the calves hanging motionless with roll and pitch angles close to zero.
5. Vocalisations between mother and calf, which included very weak tonal and grunting sounds, were produced more frequently during active dives than suckling dives, suggesting that mechanical stimuli rather than acoustic cues are used to initiate nursing.
6. Use of mechanical cues for initiating suckling and low level vocalisations with an active space of <100 m indicate a strong selection pressure for acoustic crypsis.
7. Such inconspicuous behaviour likely reduces the risk of exposure to eavesdropping predators and male humpback whale escorts that may disrupt the high proportion of time spent nursing and resting, and hence ultimately compromise calf fitness.
8. The small active space of the weak calls between mother and calf is very sensitive to increases in ambient noise from human encroachment thereby increasing the risk of mother–calf separation.

Rare bowhead whale off Dutch coast


This video says about itself:

This adventure film features Scott McVay, an authority on whales, and filmmaker Bill Mason. The objective was to film the bowhead, a magnificent inhabitant of the cold Arctic seas brought to the edge of extinction by overfishing. With helicopter and Inuit guide, aqualungs and underwater cameras, the expedition searches out and meets the bowhead and beluga.

Directed by Bill Mason – 1974

On 10 April 2017, for the first time ever, a bowhead whale was seen off the Dutch coast.

Wilma Bronke and Ingrid Pul saw it near Vlissingen in Zeeland province.

Probably, this is the same bowhead whale as the one seen off the Belgian coast on 31 March. That was the first time ever for this species in Belgium as well.

Dead whales feed other animals


This video says about itself:

Dead Whale Carcass Feast – Blue PlanetBBC Earth

26 February 2017

In Alaska, humpback whales feed on plankton in the shallow water. When one whale perishes in the treacherous waters, scavengers on the coastline such as black bears, wolves and gulls feed from the carcass.

This video says about itself:

Sharks Feasting On A Whale Carcass – Blue Planet – BBC Earth

3 March 2017

Rare footage of Sleeper Sharks, Hagfish and a whole succession of deep sea scavengers feasting on the carcass of a 30 tonne Grey Whale.

Humpback whale in Dutch harbour


This video is called Two Beautiful Humpback Whales Dance – Animal Attraction – BBC.

Dutch NOS TV reports that today a humpback whale swims in the navy harbour in Den Helder.

According to SOS Dolfijn, the whale appears to be healthy and will probably find its way back to sea.

Whales, seals feed on Antarctic krill


This video says about itself:

10 February 2017

Fur seals and whales feast on billions of krill. A chance to see fantastic images of the most abundant whales in the Southern Oceans, Minke Whales, and the awe-inspiring Humpback Whales that also visit the freezing Southern Seas in the summer.

‘EXTREMELY HIGH LEVELS’ OF TOXIC POLLUTANTS FOUND IN DEEPEST PARTS OF WORLD’S OCEANS “The study, published Monday in the journal Nature Ecology and Evolution, reportedly provides the first evidence that man-made pollutants have reached the planet’s most far-off areas, according to those behind the research.” [HuffPost]