Category: pacific ocean

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Sperm whales can take over an hour to decide together which way to go

Family of spermwhales underwater near water surface, shot from below photo credit italy sokol-dbw8sol

Generally, only spending time with their clan (numbering around 20,000), it seems that decisions about where to go, are made cooperatively in a democratic way.

Taking up to an hour to make the decision about the direction of travel, they can often travel in large groups making communal decisions about destination, route and speed, as well as when to feed and what to do about predators.

Some of these clans live over large areas, split by as much as thousands of kilometres, and it is thought to be akin to language forming in humans. Interestingly, these clans can share areas of the sea, but will only spend time with other members of their clan. Social units within clans, are based around the females, with each unit consisting of around 10 females with their offspring. These become very close, with other females babysitting young while their mothers make deep dives to feed – even suckling is done as a group.

The sperm whale has a brain which is thought to be larger than any other animal to ever live.

Over a million were killed for their very pure oil, between 1712 and 1982. There are thought to be around 300,000 in the worlds oceans, however, before whaling it is thought that there were 1.1 million.

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New DNA tests have found that blue whales have been mating with fin whales

It appears that blue whales have been mating with fin whales far more frequently than previously thought. One of the things that is both exciting and alarming, is that it suggests that whales can interbreed more easily.

While they are currently listed as endangered, and are starting to recover, of the 4 subspecies, the one found in the north Atlantic and the north Pacific is the most at risk. In otherwards, this subspecies could become extinct as a result of hybridisation.

On average around 3.5% of the blue whale DNA, comes from the fin whale.

It is perhaps odd that these species would interbreed, as blue whales weigh around 85 tonnes more than fin whales.

It had been assumed that these occasional hybrids could not go on to produce fertile offspring, but this has been shown to not be the case. What appears interesting though, is that there does not appear to be any blue whale DNA in the fin whale population, suggesting that they offspring will only ever be able to breed with blue whales.

Northern right-whale dolphin

Northern rhight whale dolphin

The northern right whale dolphin is a small, slender species of cetacean found in the cold and temperate waters of the North Pacific Ocean. Lacking a dorsal fin, and appearing superficially porpoise-like, it is one of the two species of right whale dolphin.

Northern right whale dolphins are fast swimmers. Their average swimming speed is around 26 km/h (16 mph) but they can reach speeds of up to 30–40 km/h (19-25 mph).
When travelling fast, a group looks as though they are bouncing along on the water, as they make low, graceful leaps together, sometimes travelling as far as 7 m in one leap. They can dive up to 200 m (660 ft) deep in search of squid and fish, especially lanternfish. Additionally,  also feeds on other prey items, such as Pacific hake, saury and mesopelagic fish.

It is estimated that a total of around 68,000 northern right whale dolphins inhabit the Pacific Ocean. Of those, around 26,000 (the geometric mean of their abundance estimates in US waters from 2008-2014) are placed into the California/ Oregon/ Washington stock for management purposes. Their minimum population estimate is around 18,600. Their abundances and distributions along the US coast do not only vary seasonally but also interannually, making the identification of population trends difficult.

Below is a list of any articles from this site, which mentions this species. Below that, is a video of the species in question. Below both of these we hope to add links which will help if you are looking to see this animal in the wild.

Black Dolphin

Black Dolphin (Chilean)

The Chilean dolphin , also known as the black dolphin, is one of four dolphins in the genus Cephalorhynchus. The dolphin is found only off the coast of Chile; it is commonly referred to in the country as tonina. The Chilean dolphin is small at around 1.7 metres (5 ft 7 in) in length, with a blunt head., which means that it is regularly confused with a porpoise.

The population of the Chilean dolphin, perhaps one of the least studied of all cetaceans, is not known with certainty. There may be as many as a few thousand individuals, although at least one researcher, Steve Leatherwood, has suggested the population may be much lower.

The Chilean dolphin is listed on Appendix II Convention on the Conservation of Migratory Species of Wild Animals (CMS). It is listed on Appendix II as it has an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements. The total population is thought to be under 5000.

Below, you will first find a video on this species. Under this, you will find a list of any articles that have been written on this species (or any that will be written by the time you look). Below that, I will add any links that will help you see these animals in the wild.

Pacific white-sided dolphin

Pacific white-sided dolphin

The Pacific white-sided dolphin, also called the hookfin porpoise, is an active dolphin found in the cool or temperate waters of the North Pacific Ocean.

The Pacific white-sided dolphin was named by Smithsonian mammalogist Theodore Nicholas Gill in 1865. It is morphologically similar to the dusky dolphin, which is found in the South Pacific.[6] Genetic analysis by Frank Cipriano suggests the two species diverged around two million years ago.

Though traditionally placed in the genus Lagenorhynchus. Molecular analyses indicate they are closer to dolphins of the genus Cephalorhynchus, in the Lissodelphininae subfamily, than to both the Atlantic white-sided dolphin and the White-beaked dolphin. It has therefore been proposed to move the Pacific white-sided dolphin to the resurrected genus Sagmatias together with other southern hemisphere species (hourglass dolphin, Dusky dolphin and Peale’s dolphin).  However, there is still some analysis to do, before this move can take place.  White-sided dolphins swim in groups of 10 to 100, and can often be seen bow-riding and doing somersaults. Members form a close-knit group and will often care for a sick or injured dolphin. Animals that live in such large social groups develop ways to keep in touch, with each dolphin identifying itself by a unique name-whistle. Young dolphins communicate with a touch of a flipper as they swim beside adults.

United Nations banned certain types of large fishing nets in 1933, many Pacific white-sided dolphins were killed in drift nets. Some animals are still killed each year by Japanese hunting drives

There are around 100 in dolphinarias in the USA and Japan. They are currently listed as least concern

Below is a list of any articles on the species, and below that a video of it. Under this, I will add any links that might help you see this species in the wild.

Hourglass dolphin

Hourglass dolphin

The hourglass dolphin  is a small dolphin in the family Delphinidae that inhabits offshore Antarctic and sub-Antarctic waters. It is commonly seen from ships crossing the Drake Passage, but has a circumpolar distribution.

The species was identified as a new species by Jean René Constant Quoy and Joseph Paul Gaimard in 1824 from a drawing made in the South Pacific in 1820. It is the only to have been widely accepted as a species solely on witness accounts.

Sighting surveys were conducted in 1976–77 and 1987–88. Abundance was estimated to be 144,300 individuals, based on line transect sightings in January 1977 and January 1988 in northern Antarctic waters. This is the only abundance estimate of hourglass dolphins to date.

It is currently listed as least concern on the IUCN red list.

Below you will find a video of the species, and below this a list of any articles that have (or will be) written on this species. Under this, we will over time, hope to add links which will help you see this animal in the wild.

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