- Killer whales are highly social. Some populations are composed of matrilineal family groups that are the most stable of any animal species.
- The killer whale is one of 35 species in the oceanic dolphin family, which first appeared about 11 million years ago.
- Killer whales are the largest extant members of the dolphin family. Males typically range from six to eight metres long and weigh in excess of six tonnes. Females are smaller, generally ranging from five to seven metres and weighing about three to four tonnes.
- The heart beats at a rate of about 60 beats per minute when the orca is at the surface, dropping to 30 beats per minute when submerged.
- Females breed until age 40, meaning, on average, they raise five offspring. The life spans of wild females average 50 years, with a maximum of 80 to 90 years. Males sexually mature at the age of 15, but do not typically reproduce until age 21. Wild males live around 29 years on average, with a maximum of 50 to 60 years.
- Worldwide population estimates are uncertain, but recent consensus suggests an absolute minimum of 50,000. Local estimates include roughly 25,000 in the Antarctic, 8,500 in the tropical Pacific, 2,250 to 2,700 off the cooler northeast Pacific and 500 to 1,500 off Norway. Japan's Fisheries Agency estimated 2,321 killer whales were in the seas around Japan.
Hey there, time traveller!
This article was published 4/9/2014 (2702 days ago), so information in it may no longer be current.
Part of Remi Allen's Tuesday was spent killing time with killer whales.
The 23-year-old Churchill resident received a nice surprise when several orcas made their way into Hudson Bay earlier this week. The excitement started when Dwight Allen, Remi's father, received a call from a friend inquiring about the killer whales in the bay.
The Allens immediately stopped what they were doing at their business (they own and operate Sea North Tours, a marine tour business), headed out to the marina and jumped in their six-metre Zodiac boat.
"We were probably out there for a good 20 minutes before we saw something," Remi said Thursday.
"Dwight spotted dorsal fins and at this point, we were probably a kilometre and a half out. It wasn't the calmest day, so we were in some big swells.
SEA NORTH TOURS PHOTO
Killer whales, or orcas, were once a rare sight in icy northern waters. But Churchill residents got a surprise Tuesday, Sept. 2, when a pod of the mammals showed up near the bay to feed on belugas.
"The estuary was just too shallow for them to come in."
Allen said he knew before they jumped in the boat that orcas were out there. The beluga population -- the undercard of Churchill's eco-tourism draw -- is usually sporadic this time of year. But on Tuesday, it was bumper-to-bumper beluga traffic in the shallow water where the Churchill River spills into the bay.
"They know that was the safe haven there," Allen said. "As we made our way out, there were all these belugas coming up. They were all packed in there. Get out in the bay and not a trace of them."
Allen estimates as many as 11 killer whales were out in the bay, a congregation made up of a full-sized male (bull), females, smaller adults and calves. At one point, one of the younger whales came up above the surface just a metre from the boat.
"They showed absolutely no fear towards us at all," Allen said.
"As long as I matched their speed, they didn't care if I was in the middle of their pod. They were surfacing all around us."
SEA NORTH TOURS PHOTO
Remi Allen and his father Dwight Allen, of Sea North Tours in Churchill, jumped in their six-metre Zodiac boat and headed out to the marina to watch for the whales on Tuesday.
At one time, instances of killer whales in Hudson Bay were extremely rare. As climate change affects the North, the frequency of sightings has started to increase, said David Barber, a Canada Research chair of Arctic systems science at the University of Manitoba, who specializes in Arctic marine systems.
"We have a lot less sea ice now than we used to have," Barber said. "And the amount of open water, or the duration of the open-water season, has been increasing over the last 30 years. The sea ice is a habitat and/or barrier to marine mammals in the Arctic.
"What's been happening over the last decade or so is that killer whales are now penetrating further into the Arctic and staying there longer."
Barber said their large dorsal fin made it difficult for the killer whale to manage in ice-heavy water. With that threat gone, and an abundance of new food available, northern waterways are now an attractive dinner spot.
That was the case Tuesday, when Allen found out what happened when the pod went deep into the water out of sight, only to surface a short time later.
"We ripped over to where they were, over in Button Bay, and we saw this big bloodstain in the water," he said. "I guess when they were down they killed a beluga. You could smell the blubber in the air. And the (killer whales) were moving on to the next one, like nothing had happened.
"It was pretty incredible to see."
adam.wazny@freepress.mb.ca