Although the location of the breeding or mating ground for North Atlantic right whales is unknown, researchers believe mating takes place in the winter months during large courtship groups called Surface Active Groups or SAGs. Although SAGs are seen on the spring, summer and fall feeding grounds throughout the whales' range, it is unlikely that these SAGs result in conception since females give birth between December and early March after a gestation period of 12-13 months. Therefore, actual mating must take place from November through February. Courtship groups on the feeding grounds have been known to last up to 6 hours. They include as many as 50 animals of which only one or two are females. Courtship groups are believed to be initiated by a focal female whose calls attract the males. The female then makes mating difficult by swimming on her back or diving away from the group. Males compete to reach her, actively pushing others away. When the focal female rolls upright to breathe, a male will attempt to copulate with her although copulations can also occur at the surface with the female upside down. Since multiple copulations take place during courtship groups, it is speculated that sperm competition plays a role in right whale reproduction. Supporting that theory are the size of the male testes and penis: at >800 kg, the testes are the largest in the world and the penis is among the longest, up to 3 m. In both categories they are the largest relative to body size among baleen whales. Genetic studies have shown that female right whales mate and produce calves with several different partners during their reproductive lifespan.
Here are a ton of pictures from today...
Here is a video as well I took today
THANK YOU so much to everyone who joined us, it was an incredible trip!! It total we saw about 15-20 right whales or ~5% of the world's population!!
Cheers,
Danielle
Thanks for the post, Danielle. What a perfect close to the season.
ReplyDeleteMike
Thanks Mike......but we are not done yet ;) We are whale watching with regular trips until October 16 and charters for another week after that.
ReplyDelete