As August comes to a close we say a fond farewell to the orca (or killer whale) with a bit of a bumper blog ... from Russia to the Antarctic and New Zealand to Patagonia we're covering the globe!!
Throughout August we've heard from a variety of researchers from around the world and our last project focus is on a long-term WDCS-funded project in the Avacha Gulf off eastern Kamchatka, Russia, where since 1999, researchers have been conducting photo-identification and acoustic studies on killer whales. In recent years, wide-area large ship surveys expanded the study to other regions in the Russian Far East (RFE) including: northeast Kamchatka, Commander Islands, Chukotka, Kuril Islands and northeast Sakhalin. During the field seasons 2005-2006, a total of 434 individuals were identified in the Avacha Gulf comprising at least three acoustic clans with different dialects. Most are resident-type fish-eating whales. Some transient-type marine mammal eating whales have also been recorded in Avacha Gulf and in other areas of the RFE. Transients as well as some residents show bites from the cookie cutter shark which may indicate long distance travel along the Asian coast or out to sea. Although Russian Far East killer whales can be divided into residents and transients as in the Northeast Pacific, there may be some fundamental differences due to the geomorphological characteristics of their habitat. The Russian Far East generally has a straighter shoreline with an absence of deep bays and small islands, unlike the fjordic western North American coast from Puget Sound to Alaska with its thousands of islands and islets. These differences may have an effect on killer whale distribution, size of home range, habitat use and social behavior.
Unfortunately, live captures of orca from Russian waters are still permitted to this day and in recent years at least two subadult females have been removed from the Avacha Gulf residents. A live-capture quota of 6-10 killer whales in the RFE has been granted every year since 2002 (8 for 2007) despite there being inadequate available information and data to support this decision, let alone the welfare implications of a life confined to a small concrete tank.
WDCS researchers will continue to focus their attention on these animals and to work towards a safer future for them and other cetaceans in the region.
Scientists elsewhere have recently recognized a new morph (body type) of killer whale, known as the ‘type D’ killer whale based on photographs of a 1955 mass stranding in New Zealand and six at-sea sightings since 2004. It is the most distinctive-looking form of killer whale, immediately recognizable by its extremely small white eye patch. Its geographic range appears to be circumglobal in subantarctic waters, school sizes are relatively large and although nothing is known about the their diet, it is suspected to include fish because groups have been photographed around longline vessels where they reportedly depredate Patagonian toothfish.
Briefly back to the southern resident orca (the ones in Canada!), scientists have recently reported using infrared technology to observe the orca and have found that they appear to glow in the dark! You can read the full post here!
Whilst we're here let's take a quick jaunt over to New Zealand where orca researcher Ingrid Visser gives us a brief update on what's happening with the killer whales in her neck of the woods.
"We've just had our first orca sighting of August. Incredible, given that August is normally one of the main seasons for seeing them in this area. They were travelling south and passed right by the Orca Research Centre, at Tutukaka.
One of the orca who visited yesterday is known as Funky Monkey – because of his funky dorsal fin – it is very floppy and wobbles all over the place. This is because during his teenage growth spurt the cartilage in his fin hasn’t had time to strengthen and the fin is not yet rigid like an adult male’s dorsal fin. I’ve known Funky Monkey since he was a youngster and it is great to see them growing up and watch as their lives unfold. There were approximately 10 orca in the group (I didn’t get a full head-count as they were spread out over about 2 km), including Roundtop an adult male orca who is known to frequently strand, yet typically gets off the beach without any problems."
And finally - let me leave you (and the orca blog) with some wonderful images of the seal-eating orca of Patagonia taken by WDCS's very own Rob Lott. Each year, the same orca return to feed off the seal pups, engaging a very dangerous technique of almost beaching themselves in their attempts to ambush the young pups!
And don't forget to join us again in September when it's the turn of the most magical Risso's dolphin!!