第(8/17)页mily bonds than residents transients vocalize in less variable and less plex dialects female transients are characterized by more triangular and pointed dorsal fins than those of residents the grey or white area around the dorsal fin， known as the “saddle patch“， often contains some black colouring in residents however， the saddle patches of transients are solid and uniformly grey transients roam widely along the coast; some individuals have been sighted in both southern alaska and california transients are also referred to as bigg"s orca in honour of cetologist michael bigg the term has bee increasingly mon and may eventually replace the transient label the transient ecotype is estimated to have diverged 700，000 years ago there are at least three different “stocks“ of transients off north america， the at1 stock which occurs from prince william sound to kenai fjords， the gulf of alaska\/
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