How blue and fin whales feed, new research


This 2014 video says about itself:

Sri Lanka provides sanctuary to one of the greatest Blue Whale colonies in the world.

Blue Whales are the largest animal our planet has ever known. Their tongues alone weigh more than an elephant. Their hearts are the size of a car. Despite all that, we really know very little about the magnificent Blue Whale.

From Oregon State University in the USA:

How long does a whale feed? New data gives insight into blue and fin whale behavior

September 11, 2019

Researchers using electronic tags were able to monitor blue and fin whales off the coast of Southern California over multiple weeks, providing new insight into the feeding behaviors of the two largest whale species. The researchers also found evidence of differences in the feeding intensity and habitat use of males and females of both species.

“The information collected with these tags gives us a good description of the scale of whales’ feeding behavior over periods of hours, days and weeks, which is something we’ve not been able to do before,” said Ladd Irvine, a senior faculty research assistant in Oregon State University’s Marine Mammal Institute and the study’s lead author.

The whales fed mostly during the day, usually in short bursts lasting one to two hours, but would also feed continuously throughout the daytime, and in rare circumstances for an entire day.

“We were able to quantify feeding bouts, which are periods of uninterrupted feeding, and found that the duration of feeding bouts correlated with another measure of feeding success — the number of prey capture events, known as feeding lunges,” Irvine said. “That means the whales stayed longer in areas where they fed more. This allowed us to make inferences about the profitability of feeding patches, as whales should stay in an area and feed longer where prey is abundant and move on when prey becomes scarce.”

The findings, which were published this week in the journal Frontiers in Ecology and Evolution, could have implications for managing populations of blue and fin whales, both of which are listed as endangered in the United States.

In 2014 and 2015, researchers tagged eight blue and five fin whales off the coast of Point Mugu and San Miguel Island in Southern California. Both species frequent the area, feasting on krill.

Prior whale monitoring efforts had relied solely on location tracking, which tells researchers where the whales travel, but not what happens along the way. The tags used in this study, developed at Oregon State in collaboration with Wildlife Computers Inc., included GPS for movement monitoring as well as the ability to record information about the whales’ behavior every second while they were on the move. Accelerometers and other sensors on the tags measured lunge-feeding behavior as well as frequency and depth of dives.

“The hardest thing about studying whales is that you can’t really follow them when they dive below the surface” said Irvine, who is also a doctoral student in the OSU College of Agricultural Sciences’ Department of Fisheries and Wildlife. “The data collected from these tags give us unprecedented detail about what whales are doing over a longer time period than was previously possible.”

Tags remained on the blue whales an average of 22 days and on the fin whales about 14 days. It’s unclear why the tags came off the fin whales more quickly, but it could have to do with their movement and faster speed in the water, Irvine said.

The researchers found that both species of whales had similar feeding bout characteristics. During an average feeding bout, blue whales made 24 dives over a period of about 3.3 hours, while fin whales made 19 dives over 2.7 hours. The similarities are not surprising, the researchers said, as the two species are similar in size and feed in the same way. Slight differences observed may be due to preferences in terms of patch characteristics or prey type.

“This study represents a significant leap forward in our knowledge of whale foraging ecology,” said Daniel Palacios, who holds the Endowed Faculty in Whale Habitats position at the Marine Mammal Institute and is a co-author of the paper.

“By collecting data from individual whales over multiple days and weeks, we were able to obtain large amounts of new information about how feeding intensity evolves and changes in time and space, at scales that are relevant to ecology as well as management,” he said. “We were able to answer questions like how long does a whale feed? What is the size of a feeding patch? How far does a whale need to move before it finds the next patch? Do females and males feed at the same intensity? It may seem surprising, but studying whales is enormously challenging and we lacked much of this information.”

But feeding might not be the only thing on the whales’ minds, as the researchers also found differences in movements between tagged males and females of both species.

“The males made big loops offshore of Southern California, while the females stuck closer to shore. Those routes may be related somehow to breeding behavior, and could have implications in terms of exposure to human activities if whales of one sex are more likely to be encountered in specific parts of busy Southern California waters,” Irvine said.

“While the results are exciting, our conclusions about the behaviors of whales from this initial set of data from 13 animals should be viewed as preliminary,” he said. “These data are an incredibly rich description of the tagged whales’ behavior, but they ultimately represent a relatively small number of individuals, occupying a portion of their overall range.”

Ideally, similar data would be collected again from different locations or different whales to determine if the observed feeding and other behavior patterns are representative of the broader populations, he said.

“Nevertheless, this information is a huge addition to our understanding of blue and fin whale feeding ecology,” Irvine said. “Does what we saw with these individuals hold up as we continue to study them in other places and seasons? That’s a question still to be determined. We’re still just scratching the surface of our understanding of whale behavior.”

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White ‘red’ squirrel video


This 9 September 2019 video shows a red squirrel which is not red but white; probably because of leucism.

The video is from the garden of the Grafhorst family in Ommen in Overijssel province in the Netherlands.

Extinct Schomburgk’s deer, really extinct?


This August 2018 video says about itself:

The Schomburgk’s Deer (Rucervus schomburgki) was a member of the family Cervidae.

Native to central Thailand, Schomburgk’s deer was described by Edward Blyth in 1863 and named after Sir Robert H. Schomburgk, who was the British consul in Bangkok from 1857–1864.

It is thought to have gone extinct by 1938, but there is speculation that the deer might still exist.

This graceful deer inhabited swampy plains with long grass, cane, and shrubs in central Thailand, particularly in the Chao Phraya River valley near Bangkok.

This deer avoided dense vegetation. They lived in herds that consisted of a single adult male, a few females, and their young.

The wild population of Schomburgk’s deer is thought to have died because of overhunting in 1932, with the last captive individual being killed in 1938.

The species was listed as extinct in the 2006 IUCN Red List of Threatened Species.

However, some scientists consider this species to be still extant.

In 1991, antlers were discovered in a Chinese medicine shop in Laos. Laurent Chazée, an agronomist with the United Nations, later identified the antlers from a photograph he took as coming from Schomburgk’s deer.

Only one mounted specimen is known to be in existence, which currently resides in Paris’s Muséum national d’Histoire naturelle after living in the zoo there until 1868.

From Northwestern University in the USA:

Rare deer likely lived 50 years beyond declaration of extinction

Fresh antlers from Schomburgk’s deer were photographed in Laos in 1991

September 6, 2019

A rare deer species that lived in central Thailand might have come back from the dead — without the help from sci-fi-like genetic engineering.

Schomburgk’s deer (Rucervus schomburgki) was added to the extinction list in 1938. But new evidence, gleaned from antlers obtained in late 1990 or early 1991, shows that it survived for at least an additional half-century and might still be around today.

The research was published last week (Aug. 30) in the Journal of the Bombay Natural History Society. Gary Galbreath, professor of biological sciences at Northwestern University’s Weinberg College of Arts and Sciences, was involved in the work.

After the wild population died out from overhunting in 1932, the last known Schomburgk’s deer died in captivity six years later. Or so we thought. A trucker in Laos found a set of antlers, seemingly in fresh condition, in the early 1990s. He then gave the antlers to a shop in the northern Laos province of Phongsali.

In February 1991, United Nations agronomist Laurent Chazée photographed the antlers. Galbreath and his collaborator G.B. Schroering recently analyzed the antlers’ physical condition in those photos. Based on the widely spreading, basket-shaped, hyper-branched structure of the antlers, the team determined the antlers belonged to a Schomburgk’s deer. (Other Asian deer’s antlers do not have the same signature basket shape.)

Galbreath also confirmed that the antlers were fresh when photographed in 1991. The antlers — spotted with dark red to reddish-brown dried blood — had been excised from the deer’s head. The color of the blood and condition of the exposed bone marrow offered clues into the antlers’ age.

“The relative antiquity of the antler specimens can be assessed by the materials, such as dried marrow, still adhering to them,” said Galbreath, an expert in Asian wildlife. “Even the blood was still reddish; it would become black with increased age. In the tropics, the antlers would not continue to look this way even within a matter of months.”

Before they were listed as “extinct,” the deer were well documented in Thailand. Galbreath believes a small population probably also lived in a remote area in central Laos, where they just might still be living today.

Turtle trampled by dinosaur, other discoveries


This 4 September 2019 video says about itself:

A New Species of Whale & A Turtle Trodden on by a Dinosaur– 7 Days of Science

That poor turtle! That wasn’t funny at all! What are you talking about?! Oh, before I forget, here’s a link to One World.

That turtle was Plesiochelys bigleri, from the Jurassic age in Switzerland, trampled by a sauropod dinosaur. See here.

Apparently, sauropod dinosaurs were not as good in sparing turtles’ and tortoises’ lives as these modern African elephants.

Squirrels listen to birds for safety


This 2013 video from the USA is called An Eastern Gray Squirrel eating birdseed.

From PLOS:

Squirrels listen in to birds’ conversations as signal of safety

Hearing casual chatter of birds after predator call reassures squirrels to come off high alert

September 4, 2019

Grey squirrels eavesdrop on the chatter between nearby songbirds as a sign of safety. Birds chatter when they feel safe to communicate the absence of danger or share their location. This “chatter” from multiple bird species could therefore be a useful cue to other creatures that there is no imminent threat.

To test this hypothesis, the researchers observed the behavior of 54 wild Eastern gray squirrels (Sciurus carolinensis) in public parks and residential areas in Ohio in response to threat, which they simulated by playing back a recording of the call of a red-tailed hawk (Buteo jamaicensis), a common predator of both squirrels and small birds. They followed the predator’s call with a playback of either multi-species songbird bird chatter or ambient sounds lacking bird calls and monitored the behavior of each squirrel for 3 minutes.

The researchers found that all squirrels showed an increase in predator vigilance behaviors, such as freezing, looking up, or fleeing, after they heard the hawk’s call. However, squirrels that were played bird chatter afterwards performed fewer vigilance behaviors and returned to normal levels of watchfulness more quickly than squirrels that did not hear bird calls after the hawk’s call. This suggests that the squirrels are able to tap into the casual chatter of many bird species as an indicator of safety, allowing them to quickly return to getting on with normal behaviors like foraging rather than remaining on high alert after a threat has passed.

The authors add: “We knew that squirrels eavesdropped on the alarm calls of some bird species, but we were excited to find that they also eavesdrop on non-alarm sounds that indicate the birds feel relatively safe. Perhaps in some circumstances, cues of safety could be as important as cues of danger.”