orcas
Whale Wednesday: Evolution is Cool Edition
Killer whales may be evolving into two separate species in the North Atlantic, says new research out of the UK. (Who knew orcas were common in UK waters, anyway?)
The researchers discovered that the two groups, which they have creatively dubbed "Type 1" and "Type 2" have different wear on their teeth, suggesting different diets and thus different ecological niches. Then, genetic analysis confirmed that the two types of killer whale belong to different populations.
The scientists compared the findings to how Darwin's finches adapted to fill unique ecological roles.
So what does this mean for the future of the North Atlantic killer whales? If Type 1 and Type 2 become separate species, they would require separate conservation monitoring efforts.
And if that happens, hopefully the powers that be will think of some catchier names for them.
Whale Wednesday: Stuck on Salmon
New research out of Canada indicates that some killer whale populations prefer king (a.k.a. Chinook) salmon so much that the whales will actually die when salmon numbers fall. Here's the curious part: killer whales, as apex predators, have their pick of other fish or even other large marine mammals, but still some populations appear to be dependent upon king salmon as their primary food resource. Another study from Hawaii found that killer whales can identify king salmon even when they are swimming alongside Coho and Sockeye salmon. And even in the winter, when king salmon make up just 10 to 15 percent of the salmon in the water, killer whales use echolocation to pick out their favorite fish. That's some impressively picky eating. A recovering picky eater myself, I fully relate. And king salmon are undeniably delicious. Who can blame them? But suffering king salmon populations spell trouble for the orcas. The pollock industry catches enormous amounts of king salmon as bycatch. And due to the low populations, the 2008 king salmon fishing season was cancelled in Oregon and California, and again in 2009 in California. With king salmon lovers abound on land too, something's gotta give.
Whale Wednesday: Orca Outing
Orcas live and travel in pods, which are groups of ten to twenty animals – this is not new information. However, researchers in Russia recently spotted superpods, groups of up to 100 killer whales. These meetings last anywhere from a few hours to a half day and are characterized by common social behaviors – mating, flipper rubbing, synchronized swimming – but to a higher degree than typically observed. What do these social clubs mean and why do they matter? They may simply be another avenue to socialize. Since their large numbers may actually scare off prey, they don’t seem to be an effective way to hunt. Perhaps most importantly, they may be a chance for whales from different pods to meet up and check out potential mates. With calf mortality rates as high as 50 percent in the first six months, any research into understanding orca reproduction is critical in maintaining healthy populations.
Whale Wednesday
Welcome to Whale Wednesday, the first ever hump(back) day feature devoted to cetaceans. I'm taking a cue from Oceans4Ever, the masters of alliterative weekly features, like Make a Difference Monday and Freaky Fish Friday. Hopefully this will become a semi-regular feature -- what's not to love about whales, after all? Today, three scintillating stories about cetaceans: 1. The Seattle Times reports on the first scientific review of the effort to reintegrate Keiko, the "Free Willy" orca, into the wild. The paper, which appears in the journal Marine Mammal Science, shows that while Keiko wasn't accepted by other orcas and had to be fed frozen fish until he died in 2003, he lived a longer life span than any other captive male orca. Turns out Willy's freedom was only possible on screen -- having been captured at the age of 2, he had been held in captivity too long to make it on his own.
