In the last science news digest entry, I have mentioned that I have some theories on the "suicidal attempts" of the dolphins. I'm sure some marine biologists have already covered these possibilities, but since none of them has made that well-known to the public, I will give it a whirl to offer my views.
First, we must realise that many animals behave in similar ways as human do (if you can recall, Seamore the leopard shark also behaves like a puppy). For a creature as smart as the monkeys, dolphins and whales, I reckon they also do what human beings will do. We play, we chase each other, we socialise, we sing, we chat, we dance, we war, we feel upset, we feel despair and we help each other out.
The Orcas (or killer whales), are the largest of dolphins, are supreme strategic killers which work as a team when hunting. They will not only hunt for food, but they will also go in war with other whale kinds. The following video shows a group of killer whales hunting a young grey whale in the presence of its mother grey whale. Actually, I say it is a war rather than a hunt, because in a war, warriors are cruel and cold-hearted, they share no mercy or sympathy, and their reward is simply death; consuming their kill is not an agenda, humiliating the corpse / carcass and the living is the key.
My theory 1 is FEAR: Since dolphins are related to the killer whales, they should somehow behave like them, or like humans. A group of dolphins is at war with another group, and the weaker group is desperate to retreat to the shallow or even to the beach hoping to escape from the murder. If Lady Luck in on the side of the weaker group, not all of them will die on the beach, some will live, and the stronger group might be stranded and die. The LA Times reported a grey-whales rescue case today, the article states that a young grey whale fled in fright when someone mistakenly played recordings of killer whales, which proves that fear could be a possibility.
In the next video, you will see how skilfully an orca hunt for stingrays in the shallow waters, and like the host said, the orcas are putting their life at risk in the hunting as they could be stung by the stingray, or get themselves stranded in the shallow waters.
Thus my theory 2 is FOOD, the dolphins are hunting for a creature such as shrimps or crabs very special which reside in the shallow waters, and because dolphins are highly-bonded animals, when one is stranded, others will approach the stranded as a group for the rescue, and ends up also being stranded as well.
My last theory is SUICIDE, even some people in despair commit suicide, then why won't dolphins and whales do it? But when one decides to end its life for whatever reasons, others will try to save it, just like human doctors, firemen or policemen. The difference is, there are a lot more rescuers than suicidees and the rescuers end up being the victims too.
All the above theories somehow explains why some rescued dolphins will be restranded.
All in all, not a very good topic on Valentine's Day, but this is meant to be for Monday actually. On this marvellous day, don't just love your lovers, love our oceans and sea animals too!
Vocabulary:
stranded -- (adj)
suicidal -- (adj) People who are suicidal want to kill themselves or are in a mental state in which it is likely that they will try to do so
marine biologist -- (n) the scholar of scientific study of organisms in the ocean or other marine or brackish bodies of water.
supreme -- (adj) having the highest rank, level or importance
strategic -- (adj) helping to achieve a plan, for example in business or politics
cold-hearted -- (adj) disapproving showing no understanding for or not feeling sorry about another person's suffering
mercy -- (n) [U] kindness and forgiveness shown towards someone you have authority over
sympathy -- (n) [U] (an expression of) understanding and care for someone else's suffering
humiliate -- (n) [T] to make someone feel ashamed or lose their respect for themselves
corpse -- (n) [C] a dead body, usually of a person
carcass -- (n) [C] the body of a dead animal, especially a large one that is soon to be cut up as meat or eaten by wild animals
stingray -- (n) a group of rays, which are cartilaginous fishes related to sharks.
rescue -- (vb)[T] to help someone or something out of a dangerous, harmful or unpleasant situation
scrub -- (vb) [I or T] to rub something hard in order to clean it, especially using a stiff brush, soap and water
despair -- (n) [U] the feeling that there is no hope and that you can do nothing to improve a difficult or worrying situation
Resources:
News, Science & Animals: Science News Digest (6th-9th Feb) @ Locky's English Playground
http://lockyep.blogspot.com/2012/02/news-science-animals-science-news.html
Animals and Environment: Do Sharks Deserve to Die for Their Fins? @ Locky's English Playground
http://lockyep.blogspot.com/2009/05/animals-and-environment-do-sharks.html
Killer Whales @ Wikipedia
http://en.wikipedia.org/wiki/Orcas
Orcas on the hunt @ BBC Nature
http://www.bbc.co.uk/nature/life/Killer_whale#p00k08q8
Killer whale hunt @ BBC Nature
http://www.bbc.co.uk/nature/life/Killer_whale#p004t03t
Chimps killing and eating a monkey @ YouTube
http://www.youtube.com/watch?v=KTPkmH4hWCs
Stranded Orca rescued in NZ @ YouTube
http://youtu.be/665s4AvHUVU
Dolphins at Bluff Point (Red Sea) 2009 @ YouTube
http://www.youtube.com/watch?v=pJdTLXvQzw8
Unplanned 9/11 analysis links ocean noise to whale stress @ Twincities.com
http://www.twincities.com/ci_19924178
Common dolphin makes uncommon splash in Ocean City @ Press of Atlantic City
http://www.pressofatlanticcity.com/communities/upper_capemay/common-dolphin-makes-uncommon-splash-in-ocean-city/article_675fdf2e-542b-11e1-bd4b-0019bb2963f4.html
http://dictionary.cambridge.org/dictionary/british/suicidal_1?q=suicidal+
http://en.wikipedia.org/wiki/Marine_biology
http://dictionary.cambridge.org/dictionary/british/supreme_1?q=supreme
http://dictionary.cambridge.org/dictionary/british/strategic?q=strategic+
http://dictionary.cambridge.org/dictionary/british/cold-hearted?q=cold-hearted
http://dictionary.cambridge.org/dictionary/british/mercy_1?q=mercy
http://dictionary.cambridge.org/dictionary/british/sympathy_1?q=sympathy+
http://dictionary.cambridge.org/dictionary/british/humiliate?q=humiliate
http://dictionary.cambridge.org/dictionary/british/corpse?q=corpse
http://dictionary.cambridge.org/dictionary/british/carcass?q=carcass
http://en.wikipedia.org/wiki/Stingray
http://dictionary.cambridge.org/dictionary/british/rescue_1?q=rescue
http://dictionary.cambridge.org/dictionary/british/scrub_1?q=scrub
http://dictionary.cambridge.org/dictionary/british/despair_1?q=despair+