Do Dolphins Sleep?

Have you ever asked yourself do dolphins sleep, or how? To be perfectly honest, I have not. In fact, this question was brought up by a 6-year-old kid to me last month.

We all know that dolphins (and whales) are mammals just like us. They are warm blooded and give birth to live young. In addition, they have similar bone structures.

The biggest difference is their respiratory system that allows them to spend 30 minutes or more without needing to surface for air! Many of us must be thinking they have HUGE lungs! In fact, no, the size of lungs does not determine the amount of oxygen that can be stored. Dolphin lungs contain more air cells and have two layers of capillaries compare to human lungs which has only one layer. This increases the surface area of the lungs and therefore increases the efficiency of gas exchange.

Now, back to the initial question. For mammals on land, breathing is an unconscious effort. Our body takes in air automatically. However for dolphins, it has to be a conscious effort because of their undersea environment. In other words, they have to actively decide when to breathe. It is not feasible to be totally unconscious because they need to wake up in time to breathe. Thus this is a problem because brains of a mammal need to enter into an unconscious state from time to time so that our brains can function correctly.

Scientists have studied and discovered that the solution for dolphins to sleep is to let half of the brain sleep at a time. Therefore, one half of the brain goes to sleep at one time and the other is fully aware of its surroundings. Scientists have also discovered that dolphins are in this state approximately 8 hours a day! This is the exact amount of sleep that we are advised to have as well!

Hence, the dolphins are not completely unconscious but still get the right amount of rest it needs.

How amazingly unique God has created all creatures so that they can adapt and survive in different climates and surroundings. I do think that dolphins are one of the most beautiful animals on Earth. Until today, their 'smile' still melts my heart like butter =)

Reena

CC updates! :D

Hey guys, it's me again, updating this precious cc family blog(: There has been quite a buzz going on in CC recently, so here are some updates!

1) some of the 09 Docents from various stations have decided to seek permission from the zoo management to include sharks and tigers conservation into CC station for the whole of the CNY period (till Feb end). To know more about tigers conservation and facts, you can visit HERE for more information.. We're still collating information and waiting for the management's response!
For those who are very passionate and have the time to join us in this conservation projects (not restricted to CC docents only), please join us! Click HERE to leave us a message on the wall OR simply speak to us on our tagboard (scroll down, at the right hand column) :D

2) please join "Wildlife Reserves Singapore" on Facebook! It's quite an efficient platform to learn about more about the animals you love! Click HERE to join! If you love animals and your docents job, here's the best place to get the updates of things which most visitors will not know (from behind the scenes!!!) :D

3) PP station has some newborn primate babies and some of them are endangered species in the WORLD! Pictures follow..Lion-tail macaque (above) - the most endangered macaque in the world. Don't they look like lions with their mane-stuff around the faces?

Black and white Columbus monkey

The baby is pure white in colour! As they grow older, they will turn into black and white, just like their mum and dad in the pictures!!

Family

Black Howler Monkey (female). The female is yellow to light brown in colour for their hair. As for male, theirs is black in colour. See the picture below for the baby!


Baby black howler monkey is also light brown in colour! Wonders which colour it will turn into when it grows up!

*pics courtesy of Tristan Huang from PP (09 Docents). Thank you Tristan for your willingness to share your pictures and knowledge! (=

cheers,
Angel

Gd news! (:

Night Safari expecting birth of rare baby pangolin

Wed, Jan 13, 2010 my paper

A BABY pangolin - a nocturnal mammal covered in scales, and which is also known as the scaly anteater - is expected to be born at the Night Safari as early as March this year. In a routine check on one of its four pangolins called Nita, zookeepers at the Night Safari found out that it was pregnant. They had seen it mating with its mate, Kepong, last October. The gestation period for pangolins is estimated to last five months. Mr Kumar Pillai, the Night Safari's assistant director of zoology, said: "In the wild, pangolins are becoming increasingly rare. This pregnancy is a wonderful testament to the dedication of our staff, who have been working tirelessly to ensure that this native species thrives under our care." The Night Safari introduced the pangolin habitat last February. Pangolins are delicate creatures that are notoriously difficult to keep in captivity, mainly because their diet consists solely of ants and termites, the Night Safari said yesterday.

Colugo's classification

Quoted from Norman Lim's Colugo book:

Flying Lemurs are classified in the order Dermoptera, from the Greek words derma, meaning "skin", and ptera, meaning "wing", thus "skin-wing". This is one of the smallest of all the 26 mammalian orders. There is only one family in Dermoptera, that is Cynocephalidae, from the Greek words cyno meaning" dog", and cephalus meaning "head", hence "dog-head".

Lately, results from morphological studies and molecular studies have often yielded differing views on the relationship of flying lemurs with other extant mammals. Of great interest to geneticists is the recent discovery that the genomic composition of the mitochondria in dermopterans is highly similar to that of simian primates (suborder Anthropoidea; which includes humans), making them our likely distant relatives. Professor Ulfur Amason of Lund University, Sweden went on record declaring that: "We (human beings) are more closely related to flying lemurs than we are to half-apes."

When the Colugo was excluded from the primate order, one reason was that it has a small-brain, large ventricle syndrome, something that it shares with other non-primates like the Koala of Australia (Phascolarctoscinereus) and the Three-toed Sloth of the Neotropics (Bradypustridactylus). This, however, could be due to other factors that these animals share, i.e. mainly an exclusive diet of leaves that exposes them to high levels of ph yo toxins. In other words, the toxins in the Colugo's diet might cause developmental disturbances that give it a small brain and conceal its true relationship to primates. So, while the original classification by Linnaeus was later rejected, he might in fact have been right all along in placing the Colugo among the primates!

(click image to enlarge)

So........ in summary, Colugo is a mammal in the order Dermoptera!

Cheers,
Rachel