Thursday, November 01, 2007

Dolphin Tools?

It is not often that we see nonhuman animals utilizing tools for different activities. The woodpecker finch uses cactus needles to get at food, and chimps have been observed fashioning tools to reach termites in their holes. But to think even marine animals learn to find and use tools seems pretty far-fetched.

Recently, researchers, including Michael Krützen from the University of Zurich, have noticed dolphins in Australia's Shark Bay using sponges to cover their sensitive snouts while searching for food along the ocean floor. The sponges protect the dolphin from sharp rocks along the bottom as well as from bottom-dwelling animals that can sting the dolphin as it searches for food.

Krützen and his collegues had a few hypotheses for the transmission of this behavior. To date, this 172 dolphins of Shark Bay are the only known to do the behavior and show the first observation of tool use in dolphin species. The behavior was found to have a female bias, with 1 male and 12 females exhibiting the behavior. Due to the action being found in what appeared to be a lineage from a single female bottleneck, they thought the behavior could be passed on genetically. Researchers ruled out environmental factors being a cause due to the dolphins using the sponges living with and among those that did not. Lastly, they questioned if the behavior was a result of cultural learning.

After extensive genetic testing of the lineage of sponge utilizers, researchers found that they all shared genetic markers from the maternal lineage, but this did not provide an answer to why the behavior was typically found in females. By ruling out their other hypotheses, the researchers concluded the behavior was being passed through cultural learning among some females in the Shark Bay population.

Posted by Courtney Huffman (6)



At 3:01 PM, Anonymous Anonymous said...

I don’t know if this was an intention or not, but I like how you have keyed our last class decision into this review. Those animals are using a variety of objects for play or for further advancement in their survival.
I’m interested to see more research done on this new found adaptive behavior that the dolphins of Australia’s shark bay have developed. I’m interested to learn more to why the majority of dolphins practicing this behavior are female and weather dolphins from area’s other then Australia’s shark bay have adapted the same behavior. Has this genetic link been found in only the species of bottlenecks located at shark’s bay or is the genetic link also found world wide within the bottlenecks?
I think you did a great job with this review and with sparking my interest to how this behavior with corals has developed over the years and generations.

Posted By: Rachel McMahon (6)

At 9:04 PM, Blogger PWH said...

thats just crazy. I knew dolphins were smart but I didn't know just how much. That is amazing. Very cool post.

Posted By,
Kirubakaran Sivagurunathan

At 11:42 PM, Anonymous Anonymous said...

Although this is a very amazing discovery, the use of tools by dolphins doesn't surprise me much. Dolphins are highly sophisticated mammals with a very large mental capacity. It is amazing how innovative some animals can be. The fact that the behavior may be genetic is very interesting, and it does make me wonder why it is so prevalent in females. Great work.

Posted By: Ben Tummino (6)


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