Entries in whales (13)

Tuesday
Feb182014

Counting Whales From Space

Scientists from the British Antarctic Survey have developed a method of identifying and counting Southern Right Whales Eubalaena australis using a combination of satellite photography and image processing software.

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Thursday
Jan092014

Conjoined Gray Whale calves found in Mexico

The remains of two gray whale calves joined at the waist were discovered off Baja California, the half tonne 4 metre long twins almost certainly wouldn’t have survived, it is thought that this is first incidence in the species.

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Tuesday
Sep242013

A window into the past: Blue whale ear wax

New layers of earwax are deposited year on year in the middle ear of blue whales. It is now possible to use these fatty sources to chart the blue whale’s lifetime accumulation of pollutants.

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Monday
Sep022013

Whale's skin is similar to humans!

Whales can spend up to six hours on the surface of the ocean between their dives to the depths, enjoying the warmth of the sunlight as it pierces through the water. So, how do these marine mammals protect themselves from the UV rays?

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Monday
Jul082013

Navy sonar disrupts large whales

Research has discovered that blue and beaked whales’ hunting and feeding is disturbed by navy sonar. By fitting tracking and sound recording tags to 17 blue whales and 2 blue whales, teams of researchers were able to find this out, according to two published studies.

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Monday
Jun172013

Storing oxygen; how marine mammals make deep dives

A paper in Science this week unravels how marine mammals such as whales and dolphins can remain submerged for such long stretches of time.

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Wednesday
Apr102013

How whales survived the Ice Age

Recent research into ancient mammalian species has identified DNA that shows how bowhead whales survived the last Ice Age when compared to larger cold-adapted mammals such as mammoths.

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Thursday
Nov082012

First Sighting of Rare Whale 

The rare spade-toothed beaked whale (Mesoplodon traversii) has been seen for the first time on a New Zealand beach. The species was previously only known from bones from incomplete skulls that scientists had found over 140 year period, in 1872, 1950 and 1986. This new sighting occurred after a mother and her male calf were washed up and stranded on the beach.

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Friday
Oct212011

A unicorn whale?

 

You would probably recognise them by their distinctive appearance, but how much do you know about the toothed whale, the narwhal? It turns out researchers are also vague about the specifics of a narwhal’s life and how it may change as a result of global warming.  

The WWF are trying to establish how Arctic melting is affecting ice – associated species such as the narwhal. Dr. Peter Ewins of WWF-Canada and his team tagged nine individuals in August of this year to try and establish how the elusive narwhal would cope with shrinking sea ice. Dr. Ewins is waiting on the results of their movement patterns to compare with anecdotal evidence of local Inuit’s to try and initiate a successful conservation plan. This is because narwhals are classed as near threatened by the IUCN, with their population at only approximately 50,000 - 80,000 individuals due to hunting practices for their meat and tusk.

Their long, helical tusk was thought to have initiated the fairytales of unicorns and who could blame anyone for being inspired by this mysterious species! The tusks originate from their left canine tooth and males can have tusks that reach up to 3m in length and in 1 out of 500 males, two are produced! Females also possess a tusk, but it is shorter and is not helical in shape. It is thought the tusk has evolved via sexual selection in a similar process to that of the peacock and its feathers. In addition to this, you may have thought the tusk could be used to break through ice patches enabling the narwhal to migrate with ease. However, it is thought the tusk is only used as a visual display to others as they are very rarely observed using their tusk in aggressive behavior.

They are the preyed upon by polar bears, orca and of course, humans, which further depletes their population. In addition to this, narwhals have a highly specialized diet (and therefore restricted) possibly hampering the recovery of their population in the future. When the results from this study are published it will provide greater knowledge to the scientific community when the time comes for a conservation plan for this unique species.

Haley Dolton  

Tuesday
Oct182011

Time to chill out with Sir Attenborough 

Photo courtesy of Ashley Coates

That’s right, David is back on our screens on the 26th of this month to bring us another stunning wildlife series; Frozen Planet. Little snippets of this series have been released to the media and general public over the past few days and it looks to be just as cool as the locations it's set in! A few species have already made an appearance in wildlife news recently such as crafty killer whales and thieving penguins. To get us all in the mood for the new series, here is a mini food chain detailing why some species make good predators and why some make tasty prey!

Polar bears are one of the apex predators within this food chain. Males are very large and can reach up to 350 – 680 kg and 7.9 – 9.8 ft. in length, with females measuring half that length. Because of their large size, it makes it possible for them to smash into ice dens of seals and tear into prey easily. This is assisted by shorter claws on their feet and their extremely large paws, which can measure approximately 30cm across! Their keen sense of smell also helps them when hunting prey. Polar bears are able detect unburied seals from nearly 1 mile away and buried seals under 3 ft. of snow!

Killer whales are another apex predator that drift in and out of the icy waters surrounding Antarctica and the Artic. They have a varied diet depending on which subspecies they are and their geographical location. Killer whales make excellent predators due to their high intelligence and ability to work as a team. Just recently, new images of killer whales working together to knock a seal off of an ice float have been released. A team of killer whales will rush towards an ice float causing a wave to appear that is powerful enough to knock an unsuspecting seal into the mouth of another member of their pod. They work together like this in many clever hunting situations displaying team work that some think is reinforced by their own ‘culture.’

Weddell seals are the preferred prey of apex predators as they are not as aggressive as crabeater and leopard seals, so the chance of injury by them is not as likely. Weddell seals measure between 8.2 - 11.5 ft. long and can weigh between 400 – 600kg. They are insulated with a thick layer of blubber which not only keeps them warm, but also attracts predators.  Their energy rich blubber is vital for them to stay alive because food is so hard to come by. The weddell seal does have a few tricks for avoiding gaping jaws, which are also used when hunting for their own prey. They can dive to depths of approximately 2,300 ft. and can hold their breath for around 80 minutes! That’s a very long time to play hider or seeker!  

The Frozen Planet team filmed the Adélie penguin stealing stones from neighbour’s nests to put in their own. Unfortunately for them, penguins make a tasty snack for seals and killer whales (but without the wrapper and bad joke – if you exclude that one!) Penguins may make up the bulk of a predators diet perhaps due to their sheer numbers, making them easier to locate. In the Ross Sea region of Antarctica, there are currently around 5 million Adélie penguins! This may make them an attractive option for many in such a harsh environment.

With these species featured (and I’m sure a lot more) together with the great camerawork from the BBC, I know what I will be doing on Wednesday nights!  

By Haley Dolton

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