In the huge, open waters off Californias coast, a newly determined group of transient killer whales (Orcinus orca) utilizes specialized searching methods to capture marine mammals. Now, a research study published in PLOS ONE analyzes whales in the Monterey Submarine Canyon– among the West Coasts inmost canyons– using insights into their unique searching techniques.
” In our study, transient killer whales appear to use the deep Monterey Submarine Canyon system to hunt marine mammals, while in Norway and Iceland, killer whales populations appear to utilize specific habits to confine Atlantic Herring in shallow coastal waters,” McInnes said.
The Monterey Submarine Canyon offers an unique background for these orcas to utilize their specialized searching approaches. In contrast to their peers who hunt in shallower seaside waters, these orcas tactically utilize the deep canyons topography to corral and catch marine mammals such as California sea lions, grey whale calves, and northern elephant seals.
This specific ecotype can be categorized even more into 2 distinct groups: the inner coast orcas, which hunt in shallow seaside locations, and the external coast orcas, known for their deep-water foraging activities. The behaviors and habits of the external coast orcas stay less understood due to the fact that finding killer whales in the open sea is extremely tough work for marine biologists.
To clarify this, McInnes and his fellow researchers analyzed data from marine mammal surveys performed from 2006 to 2018, together with observations from whale-watching eco-tours in between 2014 and 2021. They concentrated on the foraging patterns of outer coast short-term killer whales in and around Californias Monterey Submarine Canyon, understood for its steep shapes.
A killer whale hunts outdoors ocean. (Credit: Wikimedia Commons).
McInnes explained that although the sizes and shapes of the dorsal fins and the saddle patches on these whales are generally similar to those seen in short-term and offshore types of killer whales, theres visible variety in their fin shapes. Some whales have fins that are pointed, resembling those of short-term killer whales, while others have more rounded fins, like those found on offshore killer whales.
Orcas around the world show distinct populations or ecotypes, each with special social structures, dietary choices, and hunting methods. Amongst these, the short-term killer whales are proficient at taking advantage of marine mammals. These whales are called short-term since they are more evasive, taking unforeseeable travel routes like sea wanderers, as opposed to their resident counterparts.
” Different killer whale populations worldwide forage utilizing different habits that are specifically adjusted to searching prey in different habitats,” the University of British Columbias Joshua McInnes, the research studys first author, informed ZME Science.
In another research study published in the journal Aquatic Mammals, also out today, McInnes and coworkers go into more information about an unique whale population outdoors ocean off California and Orego. They found some of the whales had cookie-cutter shark bite scars. These are parasitic sharks that live in the open ocean, which means the orcas themselves also roam really far from the coast. In one of the monitored encounters, the orcas were seen attacking a herd of 9 adult female sperm whales. In other instances, they were seen victimizing sea turtles.
The distinct searching methods seen off of California are believed to be passed down culturally amongst the whales, highlighting the function of social knowing in their effective searching practices. Regardless of comprehensive observations, the exact technique by which transient killer whales use the shapes of the Monterey Submarine Canyon for hunting stays murky.
” It is still uncertain how short-term killer whales have the ability to use the contours of the Monterey Submarine Canyon to hunt,” McInnes stated. “This habits has been observed for several decades in this study area and in adjacent canyon systems along the coast. Our study is the first to quantify environment use patterns of transient killer whales in Monterey Bay using a geospatial analysis.”.
” Furthermore, mammal-eating killer whales in the Crozet Islands and along the exposed coasts of Patagonia utilize deliberate stranding to get southern elephant seals and southern sea lions off the beach.”.
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McInnes explained that although the sizes and shapes of the dorsal fins and the saddle spots on these whales are generally similar to those seen in transient and offshore types of killer whales, theres visible range in their fin shapes. Some whales have fins that are pointed, resembling those of transient killer whales, while others have more rounded fins, like those found on overseas killer whales. Some whales show big, evenly colored gray saddle patches, while others have smooth, narrow saddle spots, which are more normal of killer whales living in tropical areas.
” It is still uncertain how short-term killer whales are able to use the shapes of the Monterey Submarine Canyon to hunt,” McInnes stated. Our research study is the very first to quantify habitat use patterns of short-term killer whales in Monterey Bay using a geospatial analysis.”.
