Calves remain in their natal pod after independence. When a killer whale calf is born into a pod, it relies on its mother for nutrition and support. Because these animals are not monogamous, it is assumed that the fathers exhibit no parental involvement after mating. During that time, mothers teach their calves to hunt and include their offspring in the social network of their pods. They carry the calf for almost a year and a half, then give birth and nurse for another 12 months. Killer whale females invest a lot of energy in raising their offspring. Key Reproductive Features: iteroparous year-round breeding gonochoric/gonochoristic/dioecious (sexes separate) sexual viviparous Range age at sexual or reproductive maturity (male): 10 to 13 years. Range age at sexual or reproductive maturity (female): 6 to 10 years. Some studies show that almost half of all newborn calves die before their first birthday.īreeding interval: Females breed every 3 to 10 years.īreeding season: Breeding can occur at any time of the year, most often in the summer. Newborn calves nurse for about a year before weaning. Killer whales have a single calf at a time, twins have only been recorded once. Gestation takes about 14 months, although a gestation length in captivity was recorded at 539 days. The result is 4 to 6 offspring over a 25 year span. Females have a calf every 6 to 10 years and they stop breeding around the age of 40. The youngest female whale on record to give birth was 11 years old. Female killer whales begin to mate between 14 and 15 years of age. Males reach sexual maturity between 10 and 13 years old. Females reach sexual maturity between 6 and 10 years of age. However, most breeding happens in the summer, and killer whales are typically born in the fall. Killer whales can reproduce whenever females enter estrus, which can occur mutiple times a year. While killer whales are difficult to study in the wild some of their reproductive habits have been recorded and studied in captive whales. Mating System: polygynandrous (promiscuous) cooperative breeder Killer whales are polygynandrous both males and females have multiple mates throughout a season or a lifetime. Other Physical Features: endothermic homoiothermic bilateral symmetry This fin curves over either to the right or left side. In males, the erect dorsal fin can reach up to 1.8 m high in females and immature males this dorsal fin is only about 0.9 m high. Female average body size and weight is slightly smaller than that of males. The average weight for a male killer whale is 7200 kg. Newborn calves are from 2 to 2.4 m long and weigh about 136 kg at birth. The average length in females is 7 m with a maximum length of 8.5 m. The average length for a male adult is 8 m, with the maximum length at 9.75 m. Also, the white on the calf's underside has a yellow tint to it until they reach 1 year old. In calves, their black is somewhat grey up to a year old. In both sexes there is a "saddle spot" which is a grey spot behind the dorsal fin on the back. There is also a white spot above the eye. They are black on the dorsal surface, white extends from the bottom of the chin to just beyond the anus on the ventral surface. Killer whales have streamlined, black and white bodies. Perception Channels: visual tactile acoustic echolocation chemical They waves travel trough these bones, then enter into the brain via an auditory nerve.Ĭommunication Channels: visual acoustic In this auditory bulla, there are bones that are like the bones found in the human ear. The sound waves enter through the jaw where they then enter into the earbone complex. The killer whale hears the whistles and clicks through an auditory bulla (earbone complex) in its lower jaw. The whale's ears are very small openings behind the eyes, which have no outer flap. As in other toothed whales, killer whales use sonar to perceive their aquatic environment. Killer whales do have good vision, but in dark water their vision is not helpful in catching prey or navigating. Clicks seem to be used only for echolocation. This dialect has been shown to stay the same in a pod for up to six generations. Each pod has their a discrete dialect that sounds slightly different from that of other pods. They use discrete calls and whistles when communicating within and among pods. Vocalizations are used both for communication and navigation. There are 3 categories of vocalizations used by killer whales: whistles, discrete calls, and clicks.
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