T R A N S I E N T S

What are transients?

Within the species of orcinus orca, the largest member of the dolphin family, there are three distinct groups: residents, offshore, and transient killer whales.  The most closely studied type of killer whale are  the residents, then transients, but their offshore cousins have relatively no information about them since they are rarely encountered.  Transients earned their name from researcher, Dr. Mike Briggs.  He originally began studying killer whale populations in Canada to determine if their population was stable enough to allow 10 - 15 individuals be taken, per year, for the captive marine park industry.  He discovered that the populations in the Pacific North were far too small to support that number being removed from the wild, but while he gained valuable information on residents, he saw another group...  This group traveled in much smaller groups than residents, with only 3 - 4 individuals, and traveled along the rocky shores.  Dr. Briggs thought these animals were outcast, rejected by their own pods, and so he referred to them as transients.

What are the differences between residents, offshores, and transients?

The main difference between these groups boils down to: diet, habitat, vocalizations, family groups, pigmentation, morphology, and genetics, at least between residents and transients.  Offshores won't be discussed much due to a lack of research and information available.

Diet

Transients are the most fearsome predator in the ocean, they are an apex predator, which means they have no natural enemies.  Transients gave put the "killer" in killer whale, because they are whale killers.  The diet of transients is vastly different than their cousins.  Transients are primarily marine mammal feeders, which means they feed on warm-blooded marine life, instead of fish, like residents, and supposedly, offshores.  Transient killer whales will prey upon pinnipeds (seals and sea lions) and cetaceans (whales and dolphins).  They do not eat strictly those animals, as they have been know to eat seabirds, and the occasional land mammal that happened to be in the wrong place at the wrong time.  Sometimes moose, deer, bears, and other animals swim in the ocean to travel to other island areas and a killer whale may prey upon them.  Some transients also prey upon sharks.

Habitat

Transients don't have patterns of travel like the residents do.  Transients are very erratic, they don't have a normal pattern they follow.  They are nomadic, traveling in home ranges around 500 miles, whereas residents travel in migratory patterns, in 100 miles home ranges.  Killer whales live in all oceans world-wide, and one of the most widely dispersed animals.  Killer whales can be found off the coast of Norway, Iceland, the Pacific Northwest (Canada and the United States), Monterey Bay (Southern California), Russia, Japan, the Indian Ocean, Atlantic Ocean, Antarctic, and they used to have a stable population off Australia's coast, but the transient killer whales residing off Australia left by the 1930's.

Vocalizations and Family Groups

Unlike the noisy residents, always in constant contact with each other, transients are often eerily silent, but their prey can also hear them quite well too, so they can't make too much noise anyways.  Transients do vocalize, but they have a limited repertoire of calls compared to the residents.  Transient Calls | Resident Calls (A Pod)
The family group structure is also quite different.  With residents, the pod is led by the matriarch (oldest female), and her pod is made up of her sons, daughters, and her grandchildren, and they will remain with her for life.  If her daughters or sons decided to break off into their own pod, they never stray farther than "screaming" distance, and they can always be in contact with each other.  Each pod has several animals within the group, even forming gigantic superpods with other groups of residents.  Transients are much different, their pods usually consists of one adult female, and her children, but the only animal who will spend their entire life with her is her oldest son.  Sometimes transients will break off and hunt as individuals. Often pods of transients consists of 2 - 5 individuals, although larger groups may come together when hunting.

Pigmentation and Morphology

The coloration of killer whales, the pigmentation, varies on residents and transients.  The most common areas of different are the eye patches, white spots on the sides of the head, and saddle patches, the gray area behind the dorsal fin.  Eye patches in transients tend to be thinner or larger than residents, and have a distinct look to them (at least to me they do).  With saddle patches, residents have seen with 3 types of different patches: open (gray with open space in the middle), finger (gray with a small opening, a "finger" mark in the pattern), and closed (solid gray).  Transients however, tend to have closed saddle patches.  Their morphology (body shape) is also different.  Residents are much thinner, streamlined animals, whereas transients are much larger, more bulky animals.  The facial features are also different, the jaws are straight, and don't have a slight curve in them that residents have.  Transients' jaws are designed differently and allow them to open their mouths much wider than residents.  

The most noticeable feature different is the dorsal fin.  The dorsal fin is a curved crescent, while transients have sharp, triangular shaped dorsal fins.

Genetics

Research done on transients and residents has show that these animals are genetically different and breeding between the two groups does not exist.