The term whale has been generalized to refer to a variety of large marine cetaceans, which are mammalian animals that are adapted to aquatic life. However, from a taxonomic point of view, this designation is more limited, and only the species that are within the baleen group(baleen whales), animals that lack teeth, but instead have baleen, which are elastic keratin structures, located in the upper jaw. These beards allow them to nourish themselves by retaining food when they expel the water they have ingested, serving as a kind of filter.
This is a fascinating group, one of the reasons is that here we find the largest animals on the planet, such as, the blue whale. On our site we want you to know more about them, so in this article we specifically present information about how whales are born
How and when do whales mate?
Whales are generally seasonal migratory species, since they tend to define specific areas for reproduction and others for feeding. However, there are exceptions, such as the humpback whale that inhabits the Arabian Sea, which according to studies is considered a resident of the area. This preference of animals to reproduce or feed in a particular area is known as philopatry, and it varies from one species to another.
In general, whales move in winter to warmer waters to carry out their reproductive process, since the calves at birth require a period for thermoregulation until they can move to colder waters. The males in some cases can compete for the females, for which it is feasible that in some species there are certain confrontations to fertilize the female. On the other hand, it can also happen that in a group of whales ready to reproduce there are several males but only one female, and she copulates with all of them without any confrontation developing. In the end, the female will become pregnant with the male with the highest sperm quality and, in this sense, the males manage to produce large quantities of this liquid to try to guarantee their reproductive success.
Courtship is present in this group of animals, and can last more than an hourand include vocalizations or elaborate songs by the male, swimming with certain body movements and even rubbing against the female. During intercourse, the male takes out his penis, which is inside his body (as well as his testicles) and comes out of the genital slit only to introduce it to the female, who, once inside her, deposits the seminal fluid, quickly withdrawing it. Afterwards, the female will have been fertilized and should become pregnant.
Whales Gestation
Whales mature sexually between 5 and 10 years of age, but females do so earlier than males. Once the female has been fertile, the gestation period begins, which can last between 10 and 16 months, depending on the species of whale. To know them all, don't miss this other article about the Types of whales that exist.
On the other hand, whales tend to bear a single calf every two or three years, however, there are reports that these periods they can narrow in some species, especially when there is an increase in mortality rates of newborns or younger.
Here are some examples of the gestation period in some whale species:
- Humpback whale (Megaptera novaeangliae): 10-12 months.
- Blue whale (Balaenoptera musculus): 11-12 months.
- Southern whale (Eubalaena australis): 12 months.
- Boreal whale (Balaena mysticetus): about 14 months.
- Grey whale (Eschrichtius robustus): 13 months.
Given the gestation time that whales have, they usually give birth near or in the same season in which they reproduced.
How is a whale giving birth?
Mysticetes, like almost all mammals, are viviparous animals, so the embryo grows inside the female, from the which depends throughout this period. In the end, the calf is born fully developed and begins its process of suckling from the mother.
As we have mentioned, whales generally make long migratory journeys, so birthing can occur on these journeys or in places other than where fertilization occurred. At the time of birth, the whales can increase their swimming speed, show energetic movements and, if they do so on the surface, they can be seen blowing. Calves are usually born with their tails sticking out first, so this makes it easier to start swimming when they are completely out of their mother's body. However, this does not always happen, it can also happen that the calf has developed in such a way that at the time of birth it must do so by the head.
The period of lactation and maternal care of whales can last up to a year, in which the calf will stay with its mother to feed. The milk of the whales is a thick substance with a high content of fat and other nutrients necessary to satisfy the requirements of the calf, which will increase its weight and size considerably soon.
Next, we leave you a video where a whale appears giving birth to a calf, but first it is important to mention the current state of these incredible animals. Whales, due to their majesty, have caused great attraction to human beings, since they are even larger than the dinosaurs themselves. However, history has recorded that the indiscriminate hunting of these species has been truly irrational, to the point of putting them in risk of extinction Global warming, the impact on the oceans and the irruption in the migratory corridors of these animals also cause significant damage to their populations. At a global level, there are various initiatives and institutions responsible for generating various actions for the conservation of whales.
