Scientists have revealed that there is not one but two types of killer whale living in UK waters.
Each differs in its appearance and diet, with males of one type being almost two metres longer than the other.
The killer whales could be at an early stage of becoming two separate species, the researchers say.
The international group of scientists has published its results in the journal Molecular Ecology.
"It's exciting to think about two very different types of killer whale in the waters around Britain," says Dr Andy Foote from the University of Aberdeen, UK, who undertook the study.
"Killer whales aren't really a species that we think of as being a regular visitor to Britain, but in fact we have two forms of these killer whales in our waters," he told the BBC.
Scientists have found different forms of killer whale that occupy particular niches in the Pacific and the Antarctic, but this is the first time that they have been described in the North Atlantic.
Dr Andy Foote undertook the study along with colleagues from universities and museums in Denmark and the UK.
Killer whales (Orcinus orca), otherwise called orcas, live in family groups called pods.
As the largest member of the dolphin family, killer whales are known for their intelligence and range of hunting behaviours.
Tooth work
There was very little prior to this study to suggest that different types of killer whale would be found in the North Atlantic.
However, Dr Foote and colleagues studied teeth from remains of killer whales stranded over the past 200 years and found a difference in tooth wear.
"We found that one form, which we call 'type 1' had severely worn teeth in all adult specimens," explains Dr Foote.
"The other form, 'type 2', had virtually no tooth wear even in the largest adults."
In the wild, killer whales that "suck up" herring and mackerel display this tooth wear.
Knowing this, the researchers suspected a difference in diet and ecological niche between the two groups.
Dolphin predator
Using stable isotope analysis that gives clues to the orcas' diet, the scientists found that type 1 is a generalist feeder, consuming fish and seals.
Type 2, on the other hand, is a specialist feeder that scientists suspect exclusively feeds on marine mammals such as small dolphins and whales.
This specialisation for alternative ecological niches has also resulted in a difference in shape and appearance.
"The two types also differed in length, with type 2 adult males being almost two metres larger than types 1 males," Dr Foote says.
The researchers also found that colour, pattern and number of teeth vary between the groups.
Dr Foote says the fish feeding type 1 killer whales are found across the North East Atlantic and around Britain.
The cetacean hunting type 2 killer whales are regularly seen off the west coast of Scotland and Ireland.
New species
Genetic analysis indicates the two types belong to two different populations.
"Type 1 specimens were from closely related populations, but the type 2 whales were more closely related to a group of Antarctic killer whales," Dr Foote explains.
Comparing the findings with studies on killer whales around the world shows that killer whales have radiated to fill different ecological niches.
"It's similar to how Darwin's finches have adapted to different ecological roles in the Galapagos, but on a larger scale," Dr Foote notes.
He suggests this could be an important discovery for the future of the animals.
"They seem to have occupied completely different ecological niches and have started to diverge morphologically. This divergence may eventually lead to the two types becoming different species."
He also recommends the two types be considered "evolutionary significant units" and monitored separately in order to more effectively conserve one of the oceans most charismatic animals.
woensdag 6 januari 2010
maandag 4 januari 2010
J47 born to J35
January 4th, 2010
Annual Southern Resident Killer Whale population count reported to US National Marine Fisheries Service.
The Endangered Southern Resident Killer Whale (SRKW) population increased in 2009 to 87 individuals as of December 31, 2009, a net increase of two during a year in which three resident whales are missing and five were born. Three of the new babies were born into J pod, the most frequently observed of the three pods (J, K, and L) that frequent the Pacific Northwest inland marine waters of the Salish Sea. No sooner had the census report been made to the government than another new baby killer whale appeared in J pod, this one to a twelve year old female on 3 January 2010! For the time being, that means the SRKW population is back up to 88! We are optimistic that this “baby boom” in J pod represents a comeback for the resident population that went into steep decline in the mid 1990’s. Now, their survival and continued population recovery depends upon sufficient food supplies (wild salmon, particularly Chinook) in future years in this region. The whales are traveling as far as California and Haida Gwai (Queen Charlotte Islands) searching for these nutritious fish, but they keep coming back to the Salish Sea. If the whales could talk to us, they would probably say that our effort to promote wild salmon recovery in the Pacific Northwest is good for all of us, so lets do all that we can. And, lets clean up the pollution, too, so we can all eat healthy fish.
Annual Southern Resident Killer Whale population count reported to US National Marine Fisheries Service.
The Endangered Southern Resident Killer Whale (SRKW) population increased in 2009 to 87 individuals as of December 31, 2009, a net increase of two during a year in which three resident whales are missing and five were born. Three of the new babies were born into J pod, the most frequently observed of the three pods (J, K, and L) that frequent the Pacific Northwest inland marine waters of the Salish Sea. No sooner had the census report been made to the government than another new baby killer whale appeared in J pod, this one to a twelve year old female on 3 January 2010! For the time being, that means the SRKW population is back up to 88! We are optimistic that this “baby boom” in J pod represents a comeback for the resident population that went into steep decline in the mid 1990’s. Now, their survival and continued population recovery depends upon sufficient food supplies (wild salmon, particularly Chinook) in future years in this region. The whales are traveling as far as California and Haida Gwai (Queen Charlotte Islands) searching for these nutritious fish, but they keep coming back to the Salish Sea. If the whales could talk to us, they would probably say that our effort to promote wild salmon recovery in the Pacific Northwest is good for all of us, so lets do all that we can. And, lets clean up the pollution, too, so we can all eat healthy fish.
donderdag 24 december 2009
Wildlife researchers are proposing the creation of a unique, miniature conservation zone encompassing a key feeding area for a critically endangered population of killer whales near Vancouver Island.
The international team of scientists, includingUniversity of British Columbia biologist Rob Williams and colleagues from Britain and the United States, spent four months in the summer of 2006 painstakingly monitoring the movements of a three-pod population of killer whales in waters off B.C. and Washington state that numbers just 87 individuals -- so few that every animal has been identified from distinctive markings.
The researchers found the whales were about three times more likely to feast on Chinook salmon -- their preferred meal -- in a narrow coastal strip south of Washington's San Juan Island than anywhere else in their summer range.
In an article published in the latest issue of the journal Animal Conservation, the scientists propose strict protections for this whale-dining "hot spot," arguing that the no-go zone is small enough to establish a practical system for diverting boat traffic but
large enough to guarantee the whales unfettered feeding.
"Protecting even small patches of water can provide conservation benefits, as long as we choose the spots wisely," said lead researcher Erin Ashe, a biologist at Scotland's University of St Andrews, in a summary of the study.
Ms. Ashe and Mr. Williams said a sanctuary created in 1982 at the north end of Vancouver Island-- the Robson Bight Ecological Reserve -- has successfully protected an area where killer whales in a different population gather to rub their bodies on pebbled beaches.
The proposed Marine Protected Area (MPA) near San Juan Island -- a rectangular zone measuring about two kilometres by 12 kilometres -- would be the first reserve designed specifically to prevent human disturbance of a killer whale feeding ground.
The research team noted that creating a quiet environment is particularly important because the animals' behaviour is more affected by boat traffic while hunting prey than when moving along travel corridors or engaging in other activities.
"MPAs are valuable tools for conservation, but they are not our only tool," Ms. Ashe and Mr. Williams said, emphasizing the proposed exclusion zone for boats would be set within a broader area in the U.S.-Canada boundary waters that is already designated as a conservation area for killer whales.
"A smaller conservation area that is well-placed, effectively managed and has good compliance from boaters might offer additional protection within the broader critical habitat," they said.
The researchers acknowledged that tighter restrictions on human activity in an area popular for whale-watching and recreational boating could be contentious.
"The candidate no-go zone identified in our study is currently used for ecotourism, commercial and recreational fishing, marine transportation and research, and is adjacent to international shipping lanes," they said.
"For an MPA to be successful, there has to be broad, local support, and we hope that that can be achieved here ... There will be controversy, of course, but ... there is overwhelming support for killer whale conservation in the region."
Read more: http://www.nationalpost.com/news/canada/story.html?id=2376600#ixzz0amcKvAZk
The National Post is now on Facebook. Join our fan community today.
The international team of scientists, includingUniversity of British Columbia biologist Rob Williams and colleagues from Britain and the United States, spent four months in the summer of 2006 painstakingly monitoring the movements of a three-pod population of killer whales in waters off B.C. and Washington state that numbers just 87 individuals -- so few that every animal has been identified from distinctive markings.
The researchers found the whales were about three times more likely to feast on Chinook salmon -- their preferred meal -- in a narrow coastal strip south of Washington's San Juan Island than anywhere else in their summer range.
In an article published in the latest issue of the journal Animal Conservation, the scientists propose strict protections for this whale-dining "hot spot," arguing that the no-go zone is small enough to establish a practical system for diverting boat traffic but
large enough to guarantee the whales unfettered feeding.
"Protecting even small patches of water can provide conservation benefits, as long as we choose the spots wisely," said lead researcher Erin Ashe, a biologist at Scotland's University of St Andrews, in a summary of the study.
Ms. Ashe and Mr. Williams said a sanctuary created in 1982 at the north end of Vancouver Island-- the Robson Bight Ecological Reserve -- has successfully protected an area where killer whales in a different population gather to rub their bodies on pebbled beaches.
The proposed Marine Protected Area (MPA) near San Juan Island -- a rectangular zone measuring about two kilometres by 12 kilometres -- would be the first reserve designed specifically to prevent human disturbance of a killer whale feeding ground.
The research team noted that creating a quiet environment is particularly important because the animals' behaviour is more affected by boat traffic while hunting prey than when moving along travel corridors or engaging in other activities.
"MPAs are valuable tools for conservation, but they are not our only tool," Ms. Ashe and Mr. Williams said, emphasizing the proposed exclusion zone for boats would be set within a broader area in the U.S.-Canada boundary waters that is already designated as a conservation area for killer whales.
"A smaller conservation area that is well-placed, effectively managed and has good compliance from boaters might offer additional protection within the broader critical habitat," they said.
The researchers acknowledged that tighter restrictions on human activity in an area popular for whale-watching and recreational boating could be contentious.
"The candidate no-go zone identified in our study is currently used for ecotourism, commercial and recreational fishing, marine transportation and research, and is adjacent to international shipping lanes," they said.
"For an MPA to be successful, there has to be broad, local support, and we hope that that can be achieved here ... There will be controversy, of course, but ... there is overwhelming support for killer whale conservation in the region."
Read more: http://www.nationalpost.com/news/canada/story.html?id=2376600#ixzz0amcKvAZk
The National Post is now on Facebook. Join our fan community today.
donderdag 17 december 2009
Killer whales 'body-slam' dolphins in Australia attack
Australian surfers told of their horror as they watched a pod of killer whales attack a large group of dolphins, throwing them into the air and leaping to catch them.
Jamie Kidney said he was surfing off southern Australia's Eyre Peninsula with his friend Anton Storey when the ocean erupted into a seething mass of white water and "all hell broke loose".
"(It was) just chaos, you saw monstrous amounts of white water and then dolphins go flying up in the air, a killer whale would jump out of the water, grab it and body-slam it," Kidney told state radio.
"We look up out the back and these killer whales are just ramming dolphins out of the water and grabbing them, and this just kept going on and on and on, it was unreal," added Storey.
The pair estimated there were up to 100 dolphins under attack, and Kidney said the whales appeared to be toying with the mammals for fun before killing and eating them.
South Australian biologist Cath Kemper said it was "on the unusual side" to see killer whales attack dolphins so close to shore.
"They might have come in initially to look for snapper and maybe there were some dolphins around," Kemper told AFP.
"We've certainly had other reports of killer whales attacking seals and things but not necessarily dolphins.
Sometimes called "wolves of the sea", killer whales are top-order predators that eat anything from squid to larger marine mammals, she added.
Jamie Kidney said he was surfing off southern Australia's Eyre Peninsula with his friend Anton Storey when the ocean erupted into a seething mass of white water and "all hell broke loose".
"(It was) just chaos, you saw monstrous amounts of white water and then dolphins go flying up in the air, a killer whale would jump out of the water, grab it and body-slam it," Kidney told state radio.
"We look up out the back and these killer whales are just ramming dolphins out of the water and grabbing them, and this just kept going on and on and on, it was unreal," added Storey.
The pair estimated there were up to 100 dolphins under attack, and Kidney said the whales appeared to be toying with the mammals for fun before killing and eating them.
South Australian biologist Cath Kemper said it was "on the unusual side" to see killer whales attack dolphins so close to shore.
"They might have come in initially to look for snapper and maybe there were some dolphins around," Kemper told AFP.
"We've certainly had other reports of killer whales attacking seals and things but not necessarily dolphins.
Sometimes called "wolves of the sea", killer whales are top-order predators that eat anything from squid to larger marine mammals, she added.
donderdag 10 december 2009
Gray-colored transient killer whale spotted
On December 10, 2009 Capt Jim Maya, a whale watch operator from San Juan Island, photographed this white/gray colored transient killer whale. While nobody knows for sure why this whale is colored this way, grey and albino killer whales have been reported before.
In the 1970's, an albino orca in a Canadian aquarium was diagnosed with Chediak-Higashi syndrome and this syndrome could be the reason for the lack of coloration seen in the transient photographed by Capt. Jim on December 10th. Chediak-Higashi syndrome damages the immune system, increasing an animal's susceptibility to viral and bacterial infections. More specifically, it is an inherited genetic mutation that reduces the ability of white blood cells to destroy infectious agents such as bacteria. This mutation also reduces skin pigmentation, resulting in full or partial albinism. Chediak-Higashi syndrome has also been reported in humans, mice and cattle.
Genetic, infectious, parasitic and toxic diseases can impact the recovery of endangered species like the southern resident killer whales and SeaDoc has been working with other experts around the region to study and monitor diseases in killer whales. We thank Capt. Jim of Maya Westside Charters on San Juan Island for these photographs.
In the 1970's, an albino orca in a Canadian aquarium was diagnosed with Chediak-Higashi syndrome and this syndrome could be the reason for the lack of coloration seen in the transient photographed by Capt. Jim on December 10th. Chediak-Higashi syndrome damages the immune system, increasing an animal's susceptibility to viral and bacterial infections. More specifically, it is an inherited genetic mutation that reduces the ability of white blood cells to destroy infectious agents such as bacteria. This mutation also reduces skin pigmentation, resulting in full or partial albinism. Chediak-Higashi syndrome has also been reported in humans, mice and cattle.
Genetic, infectious, parasitic and toxic diseases can impact the recovery of endangered species like the southern resident killer whales and SeaDoc has been working with other experts around the region to study and monitor diseases in killer whales. We thank Capt. Jim of Maya Westside Charters on San Juan Island for these photographs.
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