We’re Not So Different After All: Male River Dolphins Attract Females With Their “Blings”

Posted on April 6, 2010 by u0901891

We men have the tendency to show off our “swagga” with our “blings” to attract the ladies. We attempt to show our “coolness” by wearing expensive watches, Armani and those Oakley shades that we all want to have. Just as we humans want to impress the opposite sex, the adult male Amazon dolphin (Inia geoffrensis), the largest of river dolphins, also carry objects as a means of sexual display to appeal their attractiveness to the female.

These pink-as-bubblegum botos (the native term for Amazon dolphin) use their long, toothy beaks to pick up weeds, piece of wood, or clumps of grass and clay that lie on the surface of the water. The pick-up action (pun intended) is followed by the thrashing of the carried object back to the surface of the water, an action which can be seen repeated several times. The adult male botos can then be seen twirling in a circle in their own axis with their fat, bulbous foreheads and elongated beak above the water.

The Amazon dolphin is unique in that no other mammal besides modern humans and chimpanzees carry objects for sexual display. This ritualistic behavior occurs during the mating seasons in the flooded Amazonian rainforests and can only be typically seen in adult male Amazon dolphins when they are among a large group of other adult males when attempting to lure the female.

Such ostentatious behavior would often result in the rise of aggression among males, which results in “beat[ing] the hell out of each other” (research indicates that they are up to 40 times more likely to get into fights than in normal situations), snapping jaws, flippers, and tails until they are “literally covered with scar tissue.” The males’ pink color–as opposed to the female’s gray color–is believed to be from scar tissue, and since a male’s attractiveness is based on how pink he is, I guess the following remark applies to both humans and river dolphins alike: Oh, the trials of love!

Glimpse of Amazon river dolphins on Youtube

For more information that emphasizes this behavior, check out this journal link on Amazon river dolphins:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2610054/

References

Choi, Charles Q. “Dolphin Bling Gets Girls.” LiveScience. TechMediaNetwork.com, 26 Mar. 2008. Web. 03 Apr. 2010. <http://www.livescience.com/animals/080326-dolphin-carry.html>.

Jenkins, Mark. “River Spirits.” National Geographic June 2009: 98-111. Print.

Martin, A. R., da Silva, V. M. F., Rothery, P., 2008, Object carrying as socio-sexual display in an aquatic mammal. Biology Letters, 4(3): 243-245.

Photo credits

1. Alicante, Camon. 2010. Photograph. Flickr. 19 Feb. 2010. Web. 3 Apr. 2010. <http://www.flickr.com/photos/tucamon/4369638183/>.

2. Martin, Tony. 2008. Photograph. Fox News. 26 Mar. 2008. 3 Apr. 2010. <http://www.foxnews.com/story/0,2933,341792,00.html>.

3. Green, Malu. 2008. Photograph. Flickr. 8 Apr. 2008. Web. 3 Apr. 2010. <http://www.flickr.com/photos/malugreen/3424361386/in/set-72157606302494638/>

Video credit

“The Mighty Amazon & River Dolphins -Wild South America – BBC.” BBCWorldwide Channel. 17 Feb. 2009. Web. 03 Apr. 2010. <http://www.youtube.com/watch?v=ta35C488dnE&feature=related>

The Dancing Bees

Posted on April 6, 2010 by u0802617

When we think of honey bees, the first thing that comes to our minds is their nasty sting. Honey bees are a subset of bees in the genus Apis. From the images above, we can see the bees flying around colourful flowers, extracting sweet nectar from them. But these creatures’ bites are far from sweet, they sting like hell!!! However, what most people don’t know is that these unattractive creatures have an artistic talent in them. They can dance!! Well it is not an actual dance, but a scientist named Karl von Frisch coined the term “Waggle Dance” to describe the way their bodies move. But what is the purpose of this dance?

Have you ever wondered how when one bee finds a food source, other bees appear at the feeding station shortly after? This shows that the bees have some kind of communication going on. Honey bees use the waggle dance to provide information about distant feeding stations to the other bees. The waggle dance shows the other bees the direction and distance to fly to find food sources.

As you can see from this diagram, the bee follows a figure 8 and waggles on the middle line of the figure 8. If the bee waggles straight up the comb, it is telling the other bees to fly towards the sun in order to find the flowers. A straight-down dance conveys to the other bees to fly directly away from the sun. Even the tempo of the dance conveys a meaning. The faster the waggle, the closer the distance of the feeding station.

This video will provide a better illustration of the waggle dance:

honey bees waggle dance

However, later experiments done showed that the waggle dance was not sufficient to aid other bees in finding the food sources. Other factors plays a part as well. Without the use of odour and visual cues in the final stages of their flight, most bees were unable to locate the food source with only the help of the waggle dance. Well this is how these creatures get their food. But as long as they waggle away from us, we are safe!!!

References:

Frisch, Karl von. 1993. The dance language and orientation of bees. Harvard Univ Press.

Riley, J. R., Greggers, U., Smith, A. D., Reynolds, D. R., & Menzel, R. (2005, May 12). The flight paths of honeybees recruited by the waggle dance. Nature Vol 435 , pp. 205-207.

“Honey bee waggle dance”- backyardbugs. Youtube Channel, 27 September 2007. URL: http://www.youtube.com/watch?v=nga4Z_HRUsU&feature=related\ (accessed on 5 April 2010)

‘Pig’ no longer a valid term of insult

Posted on April 6, 2010 by u0901398

The next time you want to yell at your little brother or sister for doing things like mistaking mothballs for Mentos chews, please note that “YOU PIG!!” or “PIG-BRAIN!” do not qualify as insults replacing the words ‘dumb’ or ‘stupid’. Yes, it has been proven, that the average human simply does not do justice to pig intelligence. In case you’re wondering—yes—such a thing actually exists.

According to Donald Broom of the University of Cambridge in England, who studies animal cognition and welfare, pigs, Sus scrofa, given a chance to experiment with mirrors first can later learn to find food based only on a mirror’s reflection.

In a test carried out by Broom and his colleagues, four pairs of pigs were “given five hours to check out a mirror in a pen. Then each pig was penned with a mirror that was angled so it reflected a bowl of apple slices or M&M’s on the other side of a partition.” When the test subjects were allowed to freely roam around the area, seven out of the eight went behind the partition and found the food. Most subjects in a control group that had no previous experience with a mirror before poked around behind it, as if they were searching for food there.

This finding “indicates assessment awareness in pigs”. Perhaps this is why, in the story of The Three Little Pigs, the third little pig had enough foresight to build his house of bricks—he probably peeked at the sorry fates of his siblings in the mirror he used to brush himself in daily and decided that he was too pretty to become a meal of the big bad wolf. Face it. Pigs ARE intelligent animals. So be sure your next insult doesn’t become an accidental compliment.

References:

“Pigs and mirrors” by J. F. Englert. The Intelligent Dog’s Guide To A Troubled Universe. URL: http://www.adogabouttown.com/?p=618 (accessed 04 April 2010)

“Pigs Use Mirrors” by Susan Milius. ScienceNews, 7 October 2009. Hosted on Science News: http://www.sciencenews.org/view/generic/id/48133/title/Pigs_use_mirrors (accessed 04 April 2010)

Donald M. Broom, Hilana Sena and Kiera L. Moynihan, 2009. Pigs learn what a mirror image represents and use it to obtain information. Animal Behaviour, 78(5): 1

MAKE WAR NOT LOVE

Posted on April 4, 2010 by u0900932

Creatures of the earth engage in various strange mating behaviors. Male giraffes drink the urine of the females; red-sided garter snakes annually form mating balls of up to 30,000 strong and the reproductive organs of male wasp spiders snap off in the female during reproduction, but ‘penis fencing’? What in the world?

Source: http://neatorama.cachefly.net/images/2007-04/flatworm-penis-fencing.jpg

‘Penis fencing’ is an unusual reproductive activity commonly practiced by the marine flatworm (Pseudobiceros hancockanus), which can grow up to about 4-6cm long. Basically, ‘penis fencing’ is an unassuming phrase that biologists use to describe the vicious battle between two hermaphrodite flatworms consisting of each of them trying to stab the skin of the other using one of its two penises. This dual may last an hour and result in gaping wounds on the body of the loser. The ritual is done to facilitate the delivery of sperm from one flatworm to another to ensure reproduction, where the first successful ‘stabber’ becomes the de-facto male and the other, the de-facto female. The de-facto female then has bear the burden of motherhood while healing her wounds.

One might wonder what motivates this seemingly placid creature to engage in such ferocious behavior against its own kind even in the absence of any kind of sex drive. Scientists suggest that it is the result of a cost-benefit analysis, where members of the hermaphrodite population weigh the benefits of stabbing, against the costs of being stabbed. The benefits of stabbing include holding control of the fertilization process and gaining direct access to the eggs under the skin of the de-facto female. In addition, the de-facto males would have the valuable opportunity to pass on their genes to even more offspring while having fewer wounds to heal. On the other end, the costs of being stabbed include expanding copious amounts of energy caring and developing the eggs whilst healing gaping wounds.

Evidently, the tremendous benefits of stabbing another vastly outweigh the costs of being stabbed, which might serve to explain why marine flatworms approach this supposed act of ‘love’ in such a primal, warlike fashion.

References:

“Fighting to mate: Flatworm penis fencing,” by Leslie Newman. PBS, n.d. URL: http://www.pbs.org/kcet/shapeoflife/episodes/hunt_explo2.html (accessed on 5 Apr 2010)

N. K. Michiels & L. J. Newman, 1998. Sex and Violence in Hermaphrodites. Nature, 391: 647.

“Flatworms penis fencing” by TheAwk.com. TheAwkblog Youtube Channel, 18 March 2009. URL: http://www.youtube.com/watch?v=5fx-YgcP8Gg (assessed on 5 April 2010)

“Spiders sacrifice genitals to ensure paternity,” by Sarah Bartlett. Cosmos Magazine, 9 Mar 2007. URL:http://www.cosmosmagazine.com/node/1093 (assessed on 5 April 2010)

“Giraffes,” by Animalcorner.co.uk. Animal Corner, n.d. URL: http://www.animalcorner.co.uk/wildlife/giraffes/giraffe_about.html (assessed on 5 April 2010)

“The Flatworms” by Lost In Arizona. Scienceray: The Great Barrier Reef: Jewels of the Sea. URL: http://s3.amazonaws.com/readers/2008/09/17/336439_5.jpg (assessed on 5 April 2010)

Babies at Risk, Cannibalism in Polar Bears

Posted on March 30, 2010 by u0802084

A male polar bear carries the head of a polar bear cub it killed and cannibalized in an area about 300 km (186 miles) north of the Canadian town of Churchill November 20, 2009. Climate change has turned some polar bears into cannibals as global warming melts their Arctic ice hunting grounds, reducing the polar bear population, according to a U.S.-led global scientific study on the impacts of climate change. Credit: REUTERS/Iain D. Williams

There has been recent coverage on cannibalistic behaviour of the polar bears (Ursus maritimus). On December 2009, it was reported in The Times that the climate change is ‘forcing polar bears to become cannibals’ (http://www.timesonline.co.uk/tol/news/environment/article6949625.ece). According to climate change campaigners, the increasing cases of polar bear cannibalism is attributed to the melting of ice and slow ice formation, leading to a decrease in platform from which to hunt seals. However, Inuit leaders (indigenous people inhabiting the Arctic regions) has classified the polar bear cannibalism occurrence as normal.

This uncommon animal behaviour has been seen before and is not the first time being documented. As early as 1985, possible cannibalism by polar bears have been recorded. It is usually the adult male that kills the young while the female tries to defend them. It was found that cannibalism among polar bears does occur under natural conditions (Lunn & Stenhouse, 1985). The reason for such occurrences are still unknown but several reasons have been suggested to explain these actions.

The initial speculation was that the adult male killed young polar bears so that the mother will breed with him. However, the male showed no interest in the adult female after the event which led to the conclusion that the killing was simply for food. Interestingly, it has been observed that the polar bears who cannibalize do not appear to be malnourished. Subsequent studies believe that infanticide may be a density dependent parameter in polar bear populations. Infanticide may be a form of population control but it does not explain the need to cannibalize on the dead cubs. There are also suggestions that geographic features play a part (Derocher & Wiig, 1999).

The reasons stated do not provide a satisfactory answer to the cannibalistic behaviour of polar bears. Although it is a natural occurrence, the climate change in contemporary world cannot be completely ruled out. To better understand the complex interacting factors of such events, more direct observational data is needed (Dyck & Daley, 2002).

A male polar bear drags the remains of a polar bear cub it killed and cannibalized in an area about 300km (186 miles) north of the Canadian town of Churchill November 20, 2009. Credit: REUTERS/Iain D. Williams

References

Lunn, NJ & Stenhouse, GB. (1985). An observation of possible cannibalism by polar bears (Ursus maritimus). Canadian Journal of Zoology/Revue Canadienne de Zoologie [CAN. J. ZOOL.]. Vol. 63, no. 6, pp. 1516-1517.

Derocher, A.E & Wiig, Ø. (1999). Infanticide and Cannibalism of Juvenile Polar Bears (Ursus maritimus) in Svalbard. ARCTIC Vol. 52, No. 3 P. 307–310 http://pubs.aina.ucalgary.ca/arctic/arctic52-3-307.pdf

Dyck, M.G & Daley, K.J. (2002). Cannibalism of a Yearling Polar Bear (Ursus maritimus) at Churchill, Canada. ARCTIC Vol. 55, No. 2 P. 190–192 http://pubs.aina.ucalgary.ca/arctic/arctic55-2-190.pdf

Blogging about animal behaviour (2010)

LSM1303 Animal Behaviour student posts

Tag Archives: group36