[00:14.47]READIGN
[00:15.62]THE LANGUAGE OF HONEY-BEES
[00:18.08]There are many different varieties of bee.
[00:20.95]Some live in large groups like the honey-bee,
[00:23.56]and make their nests in trees or holes in the rocks.
[00:27.19]Other species make their nests in holes in the ground.
[00:30.43]There are also varieties that do not live in groups at all.
[00:34.19]Among the different kinds of bee,
[00:36.23]it is the honey-bee that has interested scientists most because of the “language” they use to communicate with each other.
[00:43.89]The development of the modern beehive in 1851 made it possible to design experiments to research the language of honey-bees.
[00:52.72]Professor Karl von Frisch, a scientist from Austria,
[00:56.76]spent many years of his life researching the amazing ways honey-bees communicate in their dark hives.
[01:03.74]After working with bees of many years, Professor von Frisch was puzzled by something he had noticed again and again.
[01:12.20]When he placed little dishes of honey on a table,
[01:14.92]bees soon came.
[01:16.49]As soon as one be discovered the honey, many more came to it one after another in a short time.
[01:23.72]It seemed that one bee was able to communicate the news of food to other bees in its hive.
[01:29.36]How was this possible?
[01:30.80]To find out, von Frisch built a special hives,
[01:34.43]each with only one honeycomb.
[01:36.47]He built a transparent wall through which he could observe what went to inside.
[01:41.20]In order to tell the bees apart, he painted some bees with little dots of colour.
[01:45.93]When a marked bee returned to the hive from the feeding table,
[01:49.37]von Frisch watched through the glass.
[01:52.01]To his surprise, the bee began to perform a dace on the surface of the honeycomb.
[01:57.42]First it made a circle to the right,
[01:59.98]then to the left.
[02:01.03]It repeated theses circles over and over again.
[02:04.68]But that was not all.
[02:06.43]The dance seemed to excite the surrounding bees.
[02:09.20]They trooped behind the first dancer, copying its movements.
[02:13.72]Then the bees left the hive and went to the feeding place. The circle dance seems to communicate news of food. But what else?
[02:20.38]Von Frisch assumed that the dance conveyed more information.
[02:24.46]To find out whether his assumption was correct,
[02:27.20]he set up two feeding places.
[02:29.47]One was close to the hive,
[02:31.33]the other was much farther away,
[02:33.97]beyond some trees.
[02:35.43]He marked all the bees that came to the nearby feeding place blue,
[02:39.79]and all the bees that went to the far-away place red.
[02:43.24]When the bees came back to the hive,
[02:45.28]von Frisch saw a curious sight.
[02:47.99]All the bees that had been at the nearby feeding place were doing the circling dance.
[02:53.24]The bees that had been at the distant feeding place were doing a completely different dance,a wagging dance.
[03:00.09]The dancer ran in a straight line,
[03:02.44]wagging from side to side.
[03:04.40]Then it turned in a semicircle,
[03:06.64]ran straight again, and turned in another semicircle to the opposite side.
[03:11.79]It kept repeating the “steps” over and over.
[03:14.72]Things were clear now.
[03:16.36]It was evident that the circle dance told the bees about the location of the feeding place.
[03:21.40]It was also apparent that the wagging dance,
[03:24.43]where the bee moved sideways sent another message about the feeding place.
[03:29.37]Next, von Frisch and his colleagues set up feeding place close to the hive.
[03:34.41]Then they slowly moved it farther and farther away.
[03:37.97]Back at the hive they watched the wagging dance closely.
[03:41.70]With a stop-watch, they counted how many times the bees repeated the dance during one minute.
[03:47.55]They discovered that the farther away the feeding station was,
[03:51.31]the slower the dance was.
[03:52.96]So another astonishing fact came to light.
[03:55.81]The number of wagging dances per minute told the exact distance to the feeding place
[04:01.03]They also found out that bees fly a maximum distance of 3.2 kilometres between their hive and feeding place.
[04:09.29]The remaining question for Professor von Frisch and his partners was to find out whether bees could tell each other the exact position of a feeding place.
[04:19.03]For example, was it possible for bees to communicate precise details such as north, south, southwest and southeast?
[04:27.57]To answer the question,
[04:29.22]Professor von Frisch and his colleagues would have to obtain enough data to provide an adequate account of the bees’ behaviour.
[04:36.66]After designing more experiments
[04:38.80]they were able to clarify the procedure by which bees communicate information that they use to find and fetch food.
[04:46.46]When honey-bees have discovered a feeding place,
[04:49.33]they fly directly to it from the hive.
[04:51.79]After a short time a line of bees fly to and from the hive like a thin stream.
[04:57.82]Centuries ago, the word “bee-line” was created and today the expression “to make a beeline for someone or something” means to go quickly along a straight course for somebody or something.
[05:11.04]For his lifetime’s work in studying the communication of animals,
[05:15.09]including hone-bees, Professor Karl von Frisch was awarded a Noble Prize in 1973,
[05:22.04]which he shared with two other scientists.
[05:24.91]He died in 1982.
[05:27.37]INTEGRATING SKILLS
[05:32.33]Reading
[05:33.48]PRIMATES
[05:35.02]Like all other living creatures,
[05:37.37]human beings belong to a group of other animals that share certain characteristics.
[05:41.60]Zoologists place us in a group called primates,
[05:45.05]which include other mammals such as apes and monkeys.
[05:48.19]Among the key features found in primates are hands and feet that can grasp and often have opposable thumbs and toes.
[05:55.63]That means that primates are better than other animals at holding,
[05:59.18]moving and using objects.
[06:00.72]Indeed, many primates, most notably,
[06:03.89]human beings, have learnt to make and use tools.
[06:07.12]Primates also have a better sense of touch and the primate brain is larger-compared to body size-than that of other animals.
[06:14.39]Depending on the size of the brain,
[06:16.42]primates are divided into two groups:
[06:19.06]higher primates (human beings and apes) and lower primates.
[06:23.50]There are some 183 species of primates and they are also sometimes divided into two other groups:
[06:31.55]new world primates,
[06:33.20]which are small monkeys that live in trees, such as the spider monkey and the night monkey;
[06:39.23]old world primates include monkeys, apes and humans.
[06:43.38]They are bigger and spend more time on the ground.
[06:46.62]There are several important differences between apes and monkeys:
[06:50.85]apes have no tail, nearly all monkeys do;
[06:54.62]apes tend to be larger and walk more upright;
[06:58.14]apes use sight more than smell.
[07:00.78]Apes also have more developed brains and give birth to fewer young,
[07:05.64]which need a long time to grow up.
[07:08.28]Zoologists also make a distinction between great apes (including gorillas and chimpanzees_ and lesser apes.
[07:16.14]Most primates are social animals that live in groups and communicate with each other.
[07:21.60]A few live alone
[07:23.45]Gorillas live in groups of one male and several females,
[07:27.71]and chimpanzees live in groups of many males and many females.
[07:32.39]While their societies are different,
[07:34.84]they all communicate and behave in advanced ways.
[07:38.27]Primates use facial expressions,
[07:41.11]body language and sounds to express themselves and they can even use colour and smell to communicate.
[07:48.19]Sometimes they warn each other of danger,
[07:50.75]and they also communicate simply to keep in touch.
[07:54.12]Our closest relative among the primates is the chimpanzee,
[07:58.93]an intelligent great ape that lives in western and central Africa.
[08:03.34]Chimpanzees are about 50 centimeters to metre tall and weight around 25 to 50 kilogrammes
[08:11.60]Males are larger then females and can be up to 1.2 metres tell and weigh 70 kilogrammes.
[08:19.54]Chimpanzees have very long arms and are covered with black hair.
[08:24.19]They use the same senses as we do and their feet and hands are similar to ours,
[08:30.35]except that chimpanzees still have opposable toes and can grasp thins with their feet.
[08:37.02]Their diet is also similar to ours-they eat meat and plants-even if they sometimes feast on thins we may find disgusting,
[08:46.55]such as insects and ants.
[08:49.06]Modern science has allowed us to discover that human beings and chimpanzees are closer than we thought-our genes are more than 95% similar!
[08:59.61]Because chimpanzees and other great apes are so close to us,
[09:04.47]scientists have conducted many experiments in order to find out whether other primates can do what we do.
[09:10.71]Scientists who study animal psychology have trained chimpanzees to do all kinds of things humans do,
[09:17.66]such as solving problems and even suing language.
[09:21.50]While these experiments are interesting and useful,
[09:24.95]it is important to remember that they many not always tell us much about how chimpanzees think and what they are able to do.
[09:32.19]The reason is simple: what the chimpanzees are trained to do is not natural to them,
[09:37.83]nor does it make much sense to the animals.
[09:40.86]What may be of greater importance is to observe how primates live in the wild.
[09:45.48]How do they adapt to a changeable environment?
[09:48.36]Some animals have physical adaptations,
[09:51.10]such as the stripes of a zebra, which many help it hide from enemies,
[09:55.64]o r the body of a camel, which helps it survive in the desert.
[09:59.80]Other animals have learnt to behave in certain ways or even use primitive tools.
[10:05.13]Chimpanzees use more tools than most other animals.
[10:08.57]They use long pieces of grass to catch insects,
[10:12.13]they use stones as missiles and to crack open nuts,
[10:15.44]such as the African walnut, and they use leaves to collect and drink water |