Whales mating and reproduction By: Marjorie Flores
How do they do it? • As most mammals, whales reproduce sexually. Fertilization is internal and males have a copulatory organ and females a reproductive system. • The young are fed directly through the placenta as they develop in their mother’s wombs. After birth they feed on their mother’s milk. They basically do it the same way we do it.
Where are they? • Their body structure is design to hide their organs, both genitals and nipples to have a streamlined bodies, to swim better. • A whales penis is very long, depending on the specie, it can measure a couple of meters long. The males penis is hidden in the genital slit located midway between the anal slit, at the base of the belly and the navel. • To differentiate a male from a female, the genital slit needs to be examine, for females the slit is at the base of the belly, near the tailstock. The slit of the female contains both the vagina and the anus and it’s refer to the “genitoanal slit”. The nipples are located on either side of the slit, where a fold of skin encloses them.
What does it take? • In order for whales to find their mate they need to fight for the female. Competition is very confrontational and intense. • They are very aggressive, they can kill the other whales by just fighting for the female whale. They use all their body part as weapons. Another strategy to try to get the female, is to produce great amount of sperm for the female.
What does it take? Cont. The female has a choice in all of this, too. She can pick her mate and they always go for the bigger male, so their genetics are pass on to their offspring. It believed that some whales play song to attract the female and the female chooses that who sings the loudest. If the female is not ready to copulate or does not like her mate, she will bring her Genital slits out of the water or try to find a way for the male not to get close to it.
Intimacy • Like human, male whales get erected by the increase in blood pressure in this area and muscular contraction. • It can be controlled by muscles and encounter the female’s. • Hopefully they were successful parents.
Waiting for the little one! • Once the female is impregnated, gestation time in most whales take about 10 to 12 months. Certain species, like the sperm whale, killer whale and Pilot whale, it can last up to 16 months. • Most births take place tail first, but can also occur head first. Tail first its a lot more convenient, so they calves can breath. • They nurse their calves. They raised their calves for a certain time period.
Gestation Time and weigh • Blue whale- 11-12 months. Calves are 25 feet long and weight 6-8 tons. • Bowhead whale- 12-16 months. Calves are 17 feet long and weight 5-6 tons. • Grey whale- 13.5 months. Calves are 15 feet long and weigh 1-1.5 tons. • Humpback whales- 11-12 months. Calves are 14 feet long and weight 2.5 tons. • Minke whale- 10 months. Calves are 9 feet long and weigh 1,000 pounds. • Right whale- 12 months. Calves are 16-19 feet long and weigh 6-7 tons • Baluga whale- 14-15 months. Calves are 4-5 ft long and 100-150 pounds. • Narwal whale- 10-16 months. Calves are 5.25 feet and weigh 176 pounds. • Killer whale(orca)- 16-17 months. Calves are 6-8 feet long and weigh 600 pounds. • Sperm whale- 16 months. Calves are 13 feet long and weigh 1 ton.
Reproduction Times • Most whales reproduce during spring time or warm weather. • Females can reproduce every two to three years and reach sexual maturity around the age of 5 years (blue whales).
Sources • http://www.baleinesendirect.net/eng/1/1-3-5-6.html • “Whales of the world” by: Tom Ritchie • http://www.animalcorner.co.uk/marine/whales/whale-reproduction.html • http://www.whale-images.com/data/media/2/baby-pictures_6.jpg • http://earthobservatory.nasa.gov/Newsroom/view.php?id=23987