Welcome to the Marine Mammal and wildlife Research and Community Development Expedition blog where you can keep up to date with all the happenings and information from Kenya

Wednesday, August 25, 2010

Humpback Whales: Mating and Migration

Humpback whales are probably one of the most recognized of the marine mammals. Their well known blows and breaching make them popular with whale watchers. People are able to watch Humpbacks over the majority of the world's oceans. This is because they have an extensive migration that stretches over thousands of cold miles, and is related to feeding and mating. Humpbacks migrate north and south at different times of the year to feed, and also to breed and to have their young.

-- Humpback whale blow spotted in Wasini Channel --

Humpbacks live in distinct populations in either the north or south hemispheres. Their migration consists of travelling between high-latitude, cold water areas and low-latitude, warm water areas. This migration takes the entire year. In the winter Humpbacks can be found in low-latitude, warm water areas where they breed. These areas include; the waters off Japan, northern Australia and the nearby archipelago, the northern Indian Ocean, the east coast and certain parts of the west coast of Africa, Bermuda, and off Brazil, Panama, the Gulf of California, and Hawaii. After this season the whales spend the spring migrating u to the high-latitude, cold water areas where they live for the summer. These are the major feeding grounds for the Humpback because the cold water is very nutrient rich, and there is an abundance of krill and fish. These areas include; the southern sea by Antarctica, the Bering Sea, Atlantic Canada, and the northern sea around Greenland, Iceland, and Scandinavia. After a season of feeding the whales spend the fall moving back to the warm water areas, where calves are born and they breed.

-- We followed the mother and calf out towards the open ocean --

Breeding is also highly tied to this annual migration. The calves are born after a gestation period of around twelve months, and they are born in the warmer, low-latitude waters that the adults breed in. The calves at birth are around 13-15 feet and weigh1-2 tonnes. There are no reliable reports of Humpback females giving birth to twins. Because the Humpback populations live in different hemispheres, they have different birth peak times that coincide with that hemispheres winter, when the whales are in the warmer, tropical waters. In the Southern hemisphere the birth peak is around August, while in the Northern hemisphere the peak is February. The calves are able to begin the high-latitude migration with their mothers when they are only a few weeks old.

-- Humpbacks migrate through the region to breed and calf in warmer waters --

Here in Shimoni we have gotten the chance to see the whale migration. There have been whales in the area for at least the last month, seen by locals, but we hadn’t spotted them yet. Then, last Friday, we got our chance. We were all on base in Mkwiro, and a staff member got a call from the Science Officer in Shimoni that there were whales in the channel. We all grabbed our things and sprinted for Squirrel, our boat. We started to cross, and were almost at the Shimoni pier when we saw them. We got an even bigger treat in that sighting, for it wasn’t just one Humpback, but a mother and calf. We were all so excited, yelling like fools! The pair was heading east though the channel, and we followed them until the east end of Wasini Island. The whole experience was quite surreal, and took some time to sink in for me what had actually happened. We had seen a Humpback Whale, an animal with so many myths and stories behind them. It was a very big moment for everyone on our boat; many of the staff have gone years without being lucky enough to see a Humpback Whale, and I know that, if I see nothing else for the rest of this expo, I will be happy and feel like my time was worthwhile.