The Orca or Killer Whale (Orcinus orca) is the largest species of the oceanic dolphin family (Delphinidae). It is the second-most widely distributed mammal on Earth (after humans) and is found in all the world's oceans, from the frigid Arctic and Antarctic regions to warm, tropical seas. Orcas are highly social and generally travel in stable, matrilineal family groups.
Orcas are versatile predators, with some populations feeding mostly on fish and others on other marine mammals, including large whales.
The three types of orcas are:
Resident: These are the most commonly sighted of the three populations in the coastal waters of the northeast Pacific. The resident orcas' diet consists primarily of fish, and they live in complex and cohesive family groups known as pods. Female residents characteristically have a rounded dorsal fin tip that terminates in a sharp corner. They are known to visit certain areas consistently.
Transient: The diet of these orcas consists almost exclusively of marine mammals. They do not eat fish. Transients generally travel in small groups, usually of two to six animals. Unlike residents, transients may not always stay together as a family unit. Female transients are characterized by dorsal fins that are more triangular and pointed than those of residents.
Offshore: These orcas cruise the open oceans and feed primarily on fish, sharks and turtles. They have been seen traveling in groups of up to 60 animals. Currently there is little known about the habits of this population, but they can be distinguished genetically from the residents and transients. Female offshores are characterized by dorsal fin tips that are continuously rounded.
Orca photos taken by professional nature and wildlife stock photographer Christina Craft
Nature lovers are being urged to be mindful when looking out for marine wildlife.
Police are advising orca-watchers in particular to abide by a code of conduct in relation to marine wildlife.
Police officer George Owen said: “If you are not aware of the code then it is advisable that you research it before you venture out to sea.
“Details can be easily obtained online from various websites, namely the Scottish Natural Heritage site, or you can visit your local SNH [Scottish Natural Heritage] office in Lerwick for further information.”
He urged road users who view animals from their cars to be aware of traffic and pedestrians “at all times”.
“Please remain focussed on the road and avoid coming to a sudden halt. These lapses in concentration can lead to collisions.”
Meanwhile, walkers are being urged to remain aware of surroundings, especially when near to cliff edges.
“These animals are spectacular to see in person and can be quite captivating. Please bear in mind your own safety and the safety of others whilst enjoying them.”
The advice comes ahead of a rebrand of SNH, which will see the organisation called NatureScot from 1st May.