A group of contaminants known as persistent organic pollutants POPs comprises long-banned human-made substances that do not degrade in the environment. They include the infamous PCBs polychlorinated biphenyls known to cause hormonal imbalance, reproductive issues like a miscarriage , immune failure, and even cancer!
These chemicals are lipophilic , which means they bind to fat. The worst part is: the first pregnancy offload the most chemicals. Newborns do not have high survival chances because they receive so many chemicals that their bodies cannot process.
It just ends up slowly killing them. A baby orca found dead on the shore in Germany last year had crazy contaminant levels in its body, and they likely had something to do with its death. This means that governments should keep making efforts on contaminant management and clean-ups. If a killer whale mother has a miscarriage or stillbirth because of contaminants, she will have more chances to succeed in their next pregnancy if it comes quickly after the miscarriage.
It sounds traumatic, but this way, she will transfer fewer contaminants to her baby. This could have happened to J35, Tahlequah. Calves can get caught in the birthing canal. Calves that do make it through the birth canal need to swim to the surface and take their first breath immediately. It takes about hours to come out entirely, and when they come out tail first, they have time to acclimate to their new environment. Their flukes are not fully functional, nor do they have control over it yet, so they need a lot of assistance reaching the surface for a while.
Finally, male orcas can be a serious threat to newborns and their mothers. Often, they can become aroused during childbirth. With this many stressors, it is a miracle three babies were born in the fall of The COVID pandemic might have helped pregnant mothers by allowing them to search for food in a quieter environment.
We hope the three calves grow healthily and become strong adult orcas. And we need to remember: every killer whale baby counts towards the recovery of the Southern Residents.
She works on bioacoustics in marine mammals from the Gulf of Mexico. She is the co-founder of Whale Scientists. You can read more about her here. J41 catching a salmon, with her young calf J51 watching nearby, September Killer whale baby L swims alongside two other killer whales in the L pod: L41 and L85 in Image credit: Center for Whale Research. J35 caring around J47 back in J, Star, heavily pregnant in mid-October Gestation takes about 14 months, although a gestation length in captivity was recorded at days.
Killer whales have a single calf at a time, twins have only been recorded once. Newborn calves nurse for about a year before weaning. Some studies show that almost half of all newborn calves die before their first birthday. Killer whale females invest a lot of energy in raising their offspring. They carry the calf for almost a year and a half, then give birth and nurse for another 12 months. During that time, mothers teach their calves to hunt and include their offspring in the social network of their pods.
Because these animals are not monogamous, it is assumed that the fathers exhibit no parental involvement after mating. When a killer whale calf is born into a pod, it relies on its mother for nutrition and support. Calves remain in their natal pod after independence. Killer whale mortality rate varies with the age of the animal. The reason for these high mortality rates is unknown, but predation is not considered a primary threat during this time.
After six months, mortality rates steadily decline as killer whales learn how to protect and nourish themselves. Mortality rates are said to be the lowest around 12 to 13 years in males and 20 years in females.
The average lifespan for a female in the wild is around 63 years, with a maximum of 80 to 90 years. Male life expectancy is a bit shorter, with the average lifespan being around 36 years, with a maximum of 50 to 60 years.
Killer whales are highly social and social structure is complex. They travel in pods which can contain several to as many as 50 individuals. There has even been reports of hundreds of individuals in one pod, but this was a temporary association between a group of smaller pods.
Killer whales have limited dispersal from the maternal pod and young whales are always part of their mother's pod. Individuals in pods swim within meters of each other and coordinate their activities.
They may share prey and rarely leave the pod for more than a few hours. Killer whales teach pod members through apprenticeship. Skill in hunting and parenting are among the skills taught to younger whales. Home range size is unknown, but some studies have shown that killer whales live with their pods together in their home range for many years. While home range size is unknown, they have been documented to swim up to km a day.
There are 3 categories of vocalizations used by killer whales: whistles, discrete calls, and clicks. Vocalizations are used both for communication and navigation. They use discrete calls and whistles when communicating within and among pods. Each pod has their a discrete dialect that sounds slightly different from that of other pods.
This dialect has been shown to stay the same in a pod for up to six generations. Clicks seem to be used only for echolocation. Killer whales do have good vision, but in dark water their vision is not helpful in catching prey or navigating. As in other toothed whales , killer whales use sonar to perceive their aquatic environment. The whale's ears are very small openings behind the eyes, which have no outer flap.
The killer whale hears the whistles and clicks through an auditory bulla earbone complex in its lower jaw. The sound waves enter through the jaw where they then enter into the earbone complex. In this auditory bulla, there are bones that are like the bones found in the human ear. They waves travel trough these bones, then enter into the brain via an auditory nerve.
Bower, ; Deeke, et al. Killer whales are exceptionally successful predators. Orcinus orca diet is difficult to study and is most frequently assessed through looking at stomach contents. They eat a wide variety of large prey including: seals , sea lions , smaller whales and dolphins , fish , sharks , squid , octopi , sea turtles , sea birds, sea otters , river otters , and other animals.
Killer whales eat on average 45 kg of food a day, but they can eat much more than that. They swallow small prey whole, but tend to tear up larger prey before consumption. Killer whales are social hunters, as are wolves and lions. They often hunt in packs and use coordinated social behavior and communication to hunt prey larger than themselves, such as larger whales.
Heintzelman, ; Mann, et al. Killer whales have no natural predators, although young killer whales may be attacked by other killer whales or large sharks. They are at the top of the marine food chain. Humans sometimes prey on killer whales, but not in great numbers. Killer whales are top predators in most marine ecosystems and impact the populations of common prey, such as seals and sea lions in breeding areas.
Killer whales are host to some endoparasites and ectoparasites. They are host to killer whale lice Cyamus orcini , trematodes Fasciola skiranini , cestodes Trigonocotyle spasskyi , and nematodes Anasakis simplex. A disease that affects killer whales and is often studied is toxoplasmosis Toxoplasma gondii. While this parasite is often benign, it can have serious and fatal effects. Chadwick, ; Murata, et al.
Killer whales are hunted and used for a number of things. In various parts of the world, they are used for oil and meat. Meat is sold for human consumption or used for fertilizer or bait.
There are no known adverse effects of Orcinus orca on humans. According to the IUCN red list there is insufficient data about killer whale populations to assess their status. Whale calves will continue to feed off the milk for up to 2 years until it becomes self-sufficient to find its own food. Female whales will nurse underwater, but very close to the surface. Many animals raise their young until they mature to self-sufficiency, but this is not the case for orca whales, also known as killer whales.
One an orca whale calf reaches maturity, it will stay in the pod of whales with the mother for life, even after the offspring has offspring of its own. Despite the countless whale watching trips around the country and researchers involved in studying whale behavior and activity, the birth of a humpback whale has surprisingly never been seen before. Although an actual humpback birth has never been recorded, there is evidence suggesting that humpback whales give birth during their migration to warmer waters from colder regions, similar to other species.
Despite our limited knowledge of humpback whales, it is obvious that the mother and calf have a very close relationship.
Whale calves are always close to their mothers and significantly rely on them for food and constant protection. How Long is the Average Lifespan of a Whale? May 15, Do All Whales Have Teeth? June 18, Whale Sexual Maturity Even though whales live a long time on average, between 30 to 70 years!
Caring for Calf The mortality rate for calves is extremely high during the first year of its life, so mother whales make sure to keep a very close and protective eye over them especially after they are born. A Scientific Enigma: The Birth of Humpback Whales Despite the countless whale watching trips around the country and researchers involved in studying whale behavior and activity, the birth of a humpback whale has surprisingly never been seen before.
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