palaeopedia:The short-finned Pilot Whale, Globicephala macrorhynchus (1846)Phylum : ChordataClass :
palaeopedia:The short-finned Pilot Whale, Globicephala macrorhynchus (1846)Phylum : ChordataClass : MammaliaOrder : CetaceaFamily : DeliphinidaeGenus : GlobicephalaSpecies : G. macrorhynchusNear threatened5,5 m long and 4 500 kg (size)Oceans worldwide (map)Short-finned pilot whales are very sociable and are rarely seen alone. They are found in groups of 10 to 30, though some pods are as large as 50. In a few sitings of pods, over several hundred animals have also been recorded. Pods are primarily matrilinial, or a female-based society. Some older females have been recorded actually taking care of calves that are not their own. Males are polygynous, meaning they will mate with multiple females at one time or throughout their lives. Pods are often found with around one mature male per every eight mature females. Maturing males will often leave their birth school, but most females will stay in the same pod their entire lives. They are sometimes seen logging and will allow boats to get quite close. They rarely breach, but may be seen lobtailing (slapping their flukes on the water surface) and spy-hopping (poking their heads above the surface). Before diving, they arch their tails and raise them above the surface. When coming to the surface to breathe, adults tend to show only the tops of their heads, whereas calves will throw their entire heads out of the water. Adults occasionally porpoise (lift most of the body out of the water) when swimming particularly quickly.Females mature at about 10 years of age and will start having calves every five to eight years. A female may nurse a calf for up to 15 years as long as it is the last born calf. Their gestation period lasts just over a year, and a female will have from four to six calves in her lifetime. A calf will suckle from its mother for a minimum of two years, but most will for nearly five years. A female will usually stop reproducing once reaching the age of about 40 years The short-finned pilot whale primarily feeds on squid, but will also feed on certain species of fish and octopus. They feed nearly 1000 feet deep or more, and spend great lengths of time at depth. A pod may spread out up to a half mile to cover more area to find food. They have also been reported to “harass” sperm whales and dolphins, so marine mammals could also potentially be part of their diets. -- source link