Penguin Prostitution

On the rocky shores of the Antarctic continent, a female Adélie penguin has a large number of potential male partners to mate with. I have often heard that these penguins are monogamous,

Michael Van Woert, NOAA NESDIS, ORA, Feb 1998.
Ross Sea, Antarctica

during the mating season and even throughout their life. Also, I have commonly heard that female penguins will participate in prostitution, and exchange sexual favors for pebbles and stones for their nest. I have often wondered which is true? Are they monogomous or are they sexually promiscuous organisms.
            According to TravelWild Expeditions, Adélie penguins arrive with their colony to their breeding grounds starting in early October. Penguins at the age three and older will attempt to breed during the season. Males will spend a lot of time and energy building a nest. The nest is a shallow depression that is lined with stones and pebbles. The stones are used to hold the egg up out of freezing ice water in the event of flooding. Keeping the egg out of cold water will ensure that the egg will not freeze. Often, males will grab stones from the shores of the continent, and are even known to steal pebbles from other nests. Once the male is finished, he will stand on top of the nest and call for a female. A wandering female will check out the nest he’s prepared. If she deems the nest suitable, the two will complete a series of calls and movements. Afterwards, the male will mount the female and the pair will mate.
            On average, two eggs will be laid by the couple, and the parents will take turns incubating the egg over the course of roughly 35 day incubation period. According to the article Adélie Penguins, penguins will base their eating habits depending on if the young has been hatched. Before the egg hatches, adults will walk 50 miles away to gain access to food, but when the young penguin is born they will travel only 12 mile away for a meal. Since penguins are marine birds, and are better adapted at moving in water than the land, one mate can be without its partner for more than two to four days at a time.

Brent J. Sinclair - Chown SL, Sinclair BJ, Leinaas HP, Gaston KJ: Hemispheric Asymmetries in Biodiversity—A Serious Matter for Ecology. PLoS Biol 2/11/2004: e406. doi:10.1371/journal.pbio.0020406

            However, whether if both mates are present at the nest of not, some females have been caught by scientists participating in what appears to be acts of prostitution.  According to an excerpt from Mating in a Material World, scientists have recorded a small number of individual females who will run off to a single males nest. She will lie down in the center of the nest, and he will mate with her. Once he copulates, the female will stand up, grab a stone with her beak and bring it to her nest.  In certain cases, the female will “flirt” with the single male, and he will allow her to simply take stones from his nest. The female can take multiple stones from a single males nest during these events, and the male will not oppose or fight the female.
            The behaviors of prostitution in these penguins have both positives and negatives impacts on both the male and female. The biggest negative to prostitution would be that sex requires a lot of energy; to gain energy you need resources. In the cold Antarctic, food can be hard to come by, especially if they had just experienced a harsh winter. The two most obvious benefits: The female gets additional stones for her nest, and the single male has a chance of getting his genes into the next generation. The more rocks in the nest, the better the nest will be at protecting the egg or young penguin from suffocating or drowning. If the single male successfully fertilizes the egg the female lays, he will be able to get his genes in the next generation, but not have to expend any time or energy in caring for the offspring. If by chance, the male dies in between breeding seasons, the new pair could mate in the next breeding season. However, the exact reason for the prostitution among Adélie penguins is not known.
            Therefore, it appears that sexual behaviors vary from penguin to penguin. Although most females remain monogamous throughout the breeding season, and even throughout their lifetimes, prostitution has been documented taking place by some females in Adélie penguin breeding colonies. There are also some benefits which explain why both males and females would participate in such behaviors; such as trying to ensure that their genes make it to the next generation. On the other hand, some penguins may not follow the prostitution, because they cannot expend the energy that they have on sexual promiscuity. Overall, prostitution in Adélie penguins does actually occur, but is not a very common practice.
 

 A short excerpt on Penguin Prostitution

For Further Reading on Adélie penguins

http://animals.nationalgeographic.com/animals/birds/adelie-penguin/

Further Readings on Penguins

http://www.livescience.com/27434-penguin-facts.html

Further Readings on Animal Prostitution

http://en.wikipedia.org/wiki/Prostitution_among_animals

References  

"Mating in a Material World." McKee, Maggie. California Academy of Science and National Wildlife    Federation. February 1, 2005. Web. http://www.nwf.org/news-and-magazines/national-wildlife/birds/archives/2005/mating-in-a-material.aspx

"Adélie Penguins." AdelTravelWide Expeditions. International Association of Antarctica Tour Operators. 2014. Web. https://travelwild.com/antarctica-wildlife/adelie-penguin/

Are Five Seconds Enough

Comic by http://upload.wikimedia.org/wikipedia/commons/3/33/Five_second.png

           You and your friend are watching a movie on your couch at home, and have made popcorn for a nice movie snack. As the opening credits are scrolling on your television screen, you’re about to take that first buttery handful, when the popcorn in your hand falls onto the floor. You count, “one…two…” as you scoop up the popcorn and put it into your mouth. Your friend stares at you, to which you reply “five second rule”. The five second rule states that any food dropped on the floor is safe to eat, as long as you pick it up off the floor within five second. The reasoning: microorganisms cannot transfer from the floor onto food in five seconds. I grew    up with this phrase in my home, and I became curious to see if there is any validity to it.
             According to Dr. Paul Dawson, a food scientist at Clemons University, there is no validity to the five second rule. First, they tested to see how long Salmonella could survive in a non-favorable environment. They discovered that the bacteria could live up to four weeks on dry surfaces. Next, they dropped a “wet food” (bologna) and a “dry food” (bread) on three different types of surfaces: wood, tile, and carpet. They found, that bacteria had transferred to the food upon contact on all types of surfaces. However, the most bacteria were transferred from contact with the tile flooring, and carpet transferred the least. Also, wet food was able to obtain more bacteria. In the report Why The Five Second Rule Should Be The No Second Rule: Eating Habit Myth Exposed, stated that the bologna, which had fallen on tile had 68.6% of the bacteria transferred; while the bread had 48.7% of the bacteria transferred.
            Aston University also reported nearly identical results. However, they compared the bacteria contents of wet food on the floor for 3 seconds and 30 seconds. They discovered that wet food on the floor for 30 seconds had “contained up to 10 times more bacteria than food picked up after 3 seconds”.
            From these two experiments, it is clear that the five second rule does not have any valid evidence to support it. Although Aston University had proven that the more time spent on the floor, the more bacteria can develop on the food, it must be over a significant amount of time. Five seconds is simply not enough time. However, the ancestors of humans, like all other animals, have eaten food off of the ground, and have been digesting bacteria for millions of years. Therefore, our stomach is able to handle ingesting certain bacteria. I have eaten food off the floor multiple times in my life, and have never contracted any serious illnesses. So, use your best judgment. If the ground is dirty and the food is wet, then you may not want to eat the food. On the other hand, if you think your snack is yummy enough, and you simply don’t care, bon appetite. 

To see the experiment yourself: Here is a video from the T.V. show Mythbusters.
http://www.discovery.com/tv-shows/mythbusters/videos/five-second-rule-minimyth.htm
 
References
Clemson University. (2014). Why the Five-Second Rule Should Be the No-Second Rule: Eating Habit Myths Exposed. (http://www.clemson.edu/academics/programs/creative-inquiry/projects/spotlight/food-myth.html)

Greenemameier, Larry. (2014). Fact or Fiction?: The 5-Second Rule for Dropped Food. http://www.scientificamerican.com/article/fact-or-fiction-the-5-second-rule-for-dropped-food/

Nature’s Frankenstein Creation

            One day, a friend and I were having a conversation about the topic of evolution versus creationism. They had told me, that the duck-billed platypus is the perfect example of why evolution cannot possibly be a theory, they stated “there simply is no other creature like it. If everything is supposed to be related, how can this species fit anywhere in the tree of life”?

            The duck-billed platypus is a creature that doesn’t seem to make any sense. It has the bill and webbed feet of a duck, the tail of a beaver, and a body covered in brown fur; similar to otters. Also, they have different behavioral characteristics that are commonly found in birds and reptiles. They are one of the few living mammals that lay eggs instead of giving birth. Also, the male platypus has a barb on its hind foot, which is capable of transmitting poisons. You may find yourself thinking that there is no way a creature like this actually exists in the real world. However, this strange and fascinating creature has been around longer than our own species.

Photo from: http://www.genome.gov/dmd/img.cfm?node=Photos/Animals/Platypus_duck_billed_Getty&id=79095)

            Now that you’ve actually seen this creature for yourself, you may be wondering, where can it be found? Where did this creature come from? What kind of creature is this? Can a male platypus kill a human with their poison?
            Platypuses are known to be nocturnal creatures. Males are territorial, and have control over their habitat pools. They are found in the lakes, ponds, rivers and streams of eastern Australia and on the Island of Tasmania. They can be found either swimming in the water, or found in nearby burrows. These creatures are classified as monotreme, which means they are mammals that lay eggs. Despite its appearance, the platypus is not a hybrid species. The United States Department of Health and Human Services has estimated that the ancestor of the monotremes separated from the mammalian lineage around 166 million years ago, and gave rise to the one other living relative of the platypus, the echidna. The echidna and the platypus are distant relatives that share similar characteristic, but have very different appearances. The reason we do not see other egg-laying, duck-billed, poisonous mammals, is because its other closer relatives have gone extinct. Regardless of its species relatives, there are plenty of individuals in the platypus species, and they are nowhere close to extinction.
            The life of the platypus begins in the burrow. According to the British Broadcasting Corporation (BBC), a baby platypus is born helpless or “arterial”. This simply means that they are not fully developed when they hatch to live independently from their mother. Platypuses do not have nipples, so they nurse young by having milk ooze out of the mammary gland. After a little more than six months, the baby platypus has developed enough to live independently, and they will leave the burrow.  
            Platypuses are solitary creatures, and hunt for food on their own. According to the nature documentary Platypus- The World’s Strangest Animal, the platypus closes its eyes and nostrils when it goes under the water. To find prey, platypuses use the receptors in their beaks to sense the vibrations given off by prey on the bottom of the floor. They will then use their beaks to move stones and debris from the bottom of the water. Their diet mainly consists of small invertebrates, but they can also eat insects and small fish.
            The documentary also states, that the platypus has an elaborate mating ritual. When a male finds a female to court with, he will bite her tail until she agrees to do an underwater dance together. The male platypus still biting the females’ tail will swim around in a series of circles. Afterwards, the two will mate, and then the male will swim off, leaving the female responsible for raising the young.
            As mentioned earlier, the platypus is one of the few poisonous mammals still living on the planet, and the male is the only members who contain it. Scientists have proven that the spur is used the most during the mating season, so it is believed to be used to fight off males who wish to take over their territory. When the U.S. Department of Health and Human Services sequenced the genomes for the poisons, they discovered that the poison is due to the duplication of a certain gene that has been passed down over time. This is similar to the ways that venom production is passed from generation to generation in reptiles. However, scientists believe that these genes developed analogously. People have not been killed by platypus stings, but have reported having “pain and swelling that lasted for weeks” (Platypus-The World’s Strangest Animal).
            If you ever wander around eastern Australia, and find a strange looking creature with thick brown fur, a beak, and webbed feet, you are not going crazy. The platypus is a real creature. Whether you find it cute and adorable, or strange, the platypus will not kill you, but do not attempt to pick up or handle them, because their sting can cause severe pain. While yes, it is true that we can no longer see any living relatives that look similar to the platypus, it does not mean that a relative did not at one point exist, and have since gone extinct. Overall, the platypus, like all creatures, no matter how strange and different it may seem from all other creatures, still fits into the tree of life. 

Further readings
For more on platypus venom
http://animals.howstuffworks.com/mammals/platypus-poison1.htm

For a list of Monotremes both alive and extinct go to
http://en.wikipedia.org/wiki/Monotreme

Additional readings
http://animals.nationalgeographic.com/animals/mammals/platypus/

References
British Broadcasting Corporation. (2014). Platypus. http://www.bbc.co.uk/nature/life/Platypus/

Parer, David and Parer-Cook , Elizabeth (Producer). N/A (director). (2003). Platypus: Worlds Strangest Animal [documentary].  Australia: Australia Broadcasting Corporation, Discovery Communications, and Telecast International GmbH.  

Spencer, Geoffe. (May 7, 2008). Duck-Billed Platypus Genome Sequence Published Animal’s Reptilian-Mammalian Mix Reflected in Its DNA. http://www.nih.gov/news/health   /may2008/nhgri-07.htm