Sexual maturity in whales and dolphins

Ah puberty, those awkward years on the road to sexual maturity. It’s not clear if whales and dolphins must also suffer the dramatic ups and downs of the human teenager, but some do have to suffer big differences between the sexes when it comes to the actually timing of sexual maturity. In several posts we’ve… [read more]

Elephant seals: ocean aliens have landed!

Picture an elephant crossed with a seal and add in a little “District 9” alien. The result: the male northern elephant seal or Mirounga angustirostris. The elephant part of the description helps convey the sheer mass of the male elephant seal, plus the shape of its nose. According to the book Elephant Seals by Carole… [read more]

California, Galapagos and Japanese sea lions

I have finally made it to the “C” section of the Encyclopedia of Marine Mammals! Wow, blogging my way through the encyclopedia is going to take awhile. And so the C’s begin with the California, Galapagos and Japanese sea lions. My impression is that they were all grouped together in the C’s because California sea… [read more]

Antarctic Fur Seals

Antarctic fur seals or Acrtocephalus gazella hang out in intense cold around islands in the South Atlantic and Indian Oceans near Antarctica. Simlar to other pinnipeds, Antarctic fur seals possess an intense sexual dimorphism in size between males and females. According to the Encyclopedia of Marine Mammals, males are 1.5 times longer and weigh four… [read more]

Amazon River Dolphin: the pink dolphin

The Amazon River dolphin or Inia geoffrensisis is known locally in Brazil as boto or botovermelho. Vera da Silva, author of the Encyclopedia of Marine Mammals’ article, seems to prefer this name. Throughout the article the dolphin is referred to as “the boto.” Good nicknames for the boto could be Pepto Bismo or the Mary Kay crusader… [read more]

Aggressive Behavior in Marine Mammals: can’t we all just get along

Reading the article on aggressive behavior in the Encyclopedia of Marine Mammals is a serious downer. Don’t get me wrong, most of the information is standard wild animal behavior, which the author, Claudio Campagna, nicely summarizes in the introduction. “Aggressive or agonistic behaviors represent a conglomerate of social responses, including male disputes over territorial boundaries, female fights to protect… [read more]