Orca

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Orcinus orca - One of the most iconic creatures in the sea, an apex predator that can be found worldwide. Orcas are highly social marine mammals with their distinctive black and white markings living in long-lasting family groups called pods with as many as 20 to 30 individuals, but groups of up to 150 have been seen when pods merge to create super pods. Orca are in fact a type of dolphin.

Average Life Span:  The lifespan of an orca (killer whale) varies significantly between sexes and is also dramatically different between wild and captive populations.

In the wild: 

• Females generally live longer than males. 
  • Average female lifespan: Around 46 to 50 years, but many individuals live well into their 60s.
  • Maximum female lifespan: Some female orcas have been estimated to live as long as 80 to 100 years. "Granny" (J2), a well-known Southern Resident orca, was estimated to be over 100 years old at the time of her presumed death in 2016, though later estimates put her age closer to 65-80. More recently, "Ocean Sun" (L25) is estimated to be nearing 100.
  • Average male lifespan: Around 30 to 38 years.
  • Maximum male lifespan: Males rarely live beyond 50 to 60 years.

These figures come from long-term studies, particularly of the well-documented resident populations in the Pacific Northwest, where individual orcas have been photo-identified and tracked for decades.

In captivity:

•  The lifespan of orcas in captivity is generally much shorter than in the wild.
•  While some facilities claim comparable lifespans, independent research and data strongly suggest that captive orcas die at a significantly younger age.
•  The average lifespan of captive orcas has often been cited as being around 14 to 20 years, with very few living beyond 30 years.
•  As of 2024, Corky II is the oldest and longest-kept captive orca, at approximately 59-60 years old.

The reasons for the shorter lifespan in captivity are believed to include stress from confinement, unnatural social groupings, limited space, lack of diverse prey, and susceptibility to certain illnesses. 

Size: 13 to 20 ft  (3.96 to 6.1 m)

Weight: 500 to 1000 lbs (227 to 454 kg)

Diet: The diet of an orca (killer whale) is incredibly diverse, making them one of the most versatile predators on the planet. However, it's crucial to understand that their diet is not uniform across all orcas. Instead, different populations, known as ecotypes, have specialized diets and hunting strategies, which they pass down through generations within their pods.

Here's a breakdown of the main types of prey orcas eat, often depending on their ecotype and geographic location:

1. Marine Mammals:

• Seals and Sea Lions: A primary food source for many "transient" or "Bigg's" killer whale ecotypes, particularly in the North Pacific. They employ various hunting techniques, including "wave-washing" to knock seals off ice floes and even temporarily stranding themselves on beaches to snatch prey.
• Dolphins and Porpoises: Smaller cetaceans are also regular prey for mammal-eating orcas. 
• Whales (including larger species): Orcas are known to hunt other whale species, including minke whales, gray whale calves, and even large baleen whales like humpbacks and blue whales, often by working together in coordinated attacks. 
• Other marine mammals: This can include walruses, sea otters, and even dugongs in some regions.

 2. Fish:

• Salmon: A crucial part of the diet for "resident" killer whale ecotypes, especially in the North Pacific. Chinook salmon are a particularly preferred, fatty species. 
• Herring and Mackerel: Important for some populations in the North Atlantic (e.g., around Norway and Iceland), where orcas have developed specialized "carousel feeding" techniques to herd fish into tight balls before stunning them with tail slaps.  
• Cod, Halibut, and other groundfish: Also consumed by fish-eating orcas.
• Toothfish: In Antarctic waters, some ecotypes, like the Ross Sea Type C orcas, are known to primarily eat Antarctic toothfish.

 3. Cephalopods:

•  Squid and Octopus: These are part of the diet for various orca populations, though less common than fish or marine mammals for most. 

 4. Other Prey: 

•  Sharks and Rays: Orcas are known to prey on a variety of sharks (including great whites) and rays. They sometimes target the highly nutritious liver of sharks. 
•  Seabirds: Occasionally, orcas will catch seabirds, including penguins (especially in Antarctic waters). 
•  Sea Turtles: Less common, but have been documented. 

 Key Concepts Regarding Orca Diet:

•  Ecotypes: This is the most important concept. Orcas are not a single, homogeneous species in terms of diet. They have evolved into distinct "ecotypes" that specialize in different prey types. These ecotypes differ not only in diet but also in hunting techniques, vocalizations, social structure, and even subtle physical characteristics. They generally do not interbreed or interact. 
•  Cooperative Hunting: Orcas are highly intelligent and social animals. They often hunt in pods, using sophisticated and coordinated strategies to catch their prey. 
•  Learned Behaviors: Hunting techniques are learned and passed down through generations within pods, contributing to the distinct diets of different ecotypes. 
•  Top Predators: Orcas are apex predators, meaning they are at the top of their food chain and have no natural predators. 
•  Dietary Specialization and Conservation: The high degree of dietary specialization makes some orca populations vulnerable to declines in their preferred prey species. For example, the Southern Resident killer whales in the Pacific Northwest are highly dependent on Chinook salmon, and their population is struggling due to salmon declines.

 In summary, while an orca can eat a wide variety of animals, what a specific orca eats depends on which ecotype it belongs to and its geographical location.