Ch1 - Giraffe
Giraffe is the tallest animal on Earth. The largest specimens reach up to 6 meters and can weigh even 2000 kg.
Giraffes live in Africa. In their natural environment, these animals stay in groups of up to several dozen mammals. What is interesting, those aggregations include not only giraffes, but also zebras and antelopes. This close relationship helps them in avoiding predators: when giraffes recognize danger and start to flee, other animals follow.
Giraffes usually stay in savannahs, vast grasslands with few trees. However, we can find there acacias, which are giraffe’s favorite treat – especially their leaves. Giraffes spend up to 20 hours a day searching and consumming their food. During that time, they eat about 35 kg of plants.
Since acacia leaves are very juicy, giraffes are very resistant to drought. Provided they have access to fresh food, giraffes can live without water for many months. Usually, they drink once a week, at one time consuming up to 50 liters of water!
Adult males fight by “necking”: opponents bend each other's long necks or turn their heads. This ritual may look like they’re kissing, but in reality, it is a custom that helps in establishing giraffes' social hierarchy.
According to scientists, these fights are one of the reasons behind giraffes' long, muscular necks. The giraffe with the strongest neck wins the fight; consequently, he is more attractive to the females and has a bigger chance of having offspring. Children inherit their necks from their father, so the next generation is more probable to have stronger and longer necks in order to fight their way to the top of the hierarchy. Thus, giraffes get constantly taller.
Another scientific explanation for giraffes’ long necks is their eating habits. Most animals living on savannah eat plants that are easy to access and available on the ground. Thanks to their long necks, giraffes can reach leaves of tall acacias and do not have to fight with other animals. It helps especially during the drought season, when food is scarce.
Another interesting fact about giraffes is their tongue. It is hard, blue-black in color and can stretch even up to 46 cm. This allows giraffes to reach the highest acacia’s leaves without the risk of getting sun burnt or cutting itself on acacia’s thorns.
Giraffe’s coat has dark patches resembling colors and patterns characteristic to savannah and as such, it serves as a camouflage. Each giraffe has a distinct pattern of blotches, unique like fingerprints of every human. In some regions of Africa, there exist groups of giraffes that share similar patterns. Although the shape of blotches doesn’t change throughout the giraffe’s lifetime, their color may. It varies depending on the time of year, giraffe’s well-being and its diet.
In the past, people believed that giraffes descended from camels (in Latin: Camelus) and leopards (Panthera Pardus). This misconception became the grounds for the giraffe's official Latin name – Giraffa camelopardalis.
Giraffes have a curious way of walking, called "pace". First, they simultaneously move their legs on one side of the body, then do the same on the other side.
Giraffes are the only species, except for humans, measured to the top of their head. Other animals' height is assessed at the withers – the highest fragment of their back.
On average, a giraffe sleeps from 5 hours to 30 minutes a day. Giraffes usually sleep in standing position and take short naps. Each nap takes about a minute. When they are really tired, however, they lie down. They curl into a ball and rest their heads on their behinds.
Due to their impressive size, giraffes do not have many natural enemies. Only a lion or a crocodile could pose a threat to an adult giraffe. Even so, giraffes are not defenseless – they can attack with their enormous hooves, big as dinner plates!
Giraffes’ legs are very long and thin. They can measure up to 2 meters long and the front legs are always longer than the ones in the back. In spite of their frail anatomy, giraffes are great runners: they can sprint at the speed of 55 km/h.
Giraffes’ long tails end with dark tuft of hair and are used against insects. Since ages, their practicality was appreciated by the Maasai people; they used giraffes’ tails as fly swatters. Moreover, these tails were regarded as a symbol of masculinity and power, and also served as a kind of scepter.
Despite its impressive length, giraffe’s neck is composed of merely 7 bones (called vertebrae), exactly like a human neck. Giraffe’s vertebrae, however, are much longer – up to 25 cm long each. The whole spine consists of 24 vertebrae.
Giraffes’ necks are adorned with a mane. It is quite similar to a horse’s mane, but a lot shorter.
The Giraffes’ horn-like ossicones are essentially made of ossified cartilage – the same tissue that forms our noses (only ours is a bit softer). Female giraffes’ ossicones usually have some hair on top and are shorter in comparison to the males'.
Build
To build this model, you will need LEGO Education WeDo 2.0
Explore
The robot resembles a giraffe, and once programmed, it will nibble on twig leaves straight from a tree.
Just like a real giraffe, this model has a long neck, ossicones, thin long legs and a tail.
1. The giraffe model is propelled by a motor installed on its back.
2. Next to the giraffe you can see a hub, which powers the construction, reads the program commands and controls the motor appropriately.
The mechanism controlling the giraffe’s head relies on four cogwheels.
1. The small cogwheel on a red axle is directly connected to the motor and propels the whole construction.
2. Two cogwheels in the middle serve as a power transmission.
3. The last, big cogwheel is connected with the giraffe’s neck, which moves along.
Since the first cogwheel is smaller than the last one, this is a reduction gear transmission.
1. The giraffe’s long, thin legs are made of four axles with different lengths.
2. The hind legs are affixed to the base thanks to the axle holes in the round plates.
3. The forelegs loosely fit into “hooves” with round holes.
1. In front, there is a tree with leaves for the giraffe to eat.
2. Two lime plates imitate the foliage. They stay in place by means of black pins, but can be tilted to look more natural.
The giraffe’s torso has a number of useful functions.
1. This is a space for the motor.
2. In the back, there is a place for the giraffe’s tail.
3. Cogwheels can be aligned thanks to the holes in the lime Technic beam.
4. The giraffe’s neck is loosely attached between the two beams.
The most interesting element of this robot is its mobile neck.
1. Since the neck can be tilted, the giraffe can reach out for leaves time and again.
2. The neck is installed on a brick with pin from one side, and from the other on the axle connected with gear transmission. Both elements must be perfectly aligned.
3. The giraffe’s head has all its characteristic elements: mane, ossicones… it even has some leaves in its mouth!
Program
This is the Start Block. It marks the beginning of the giraffe’s program.
Clicking on it will run the script.
Behind it, you will pin all following commands.
