Ch9 - Parrots
Parrots are beautiful birds with amazingly colorful feathers. There is almost 400 parrot species, which can be found in the widest diversity in South America and Australia.
Parrot species differ in size, color and lifestyle. However, all of them have a massive, curved bill, a thick tongue, and they tend to be sociable.
Parrots are sticklers for neatness. They use their bills to clean their feathers, and they pay special attention to those on their head and neck; these feathers are most likely to get dirty with food or juices. For some species, the cleaning process became a ritual.
Some parrots have a distinctive crest on top of their heads. This ornament can be seen on cockatoos and cockatiels.
Parrots have extraordinary legs. Other birds usually have three toes pointing forwards and one pointing backwards. Parrots, on the other hand, have two toes pointing forwards and two pointing backwards, which improves their stability when climbing trees to getting their tidbits.
Parrots owe their gallant colors to pigments acquired from their food: fruits, seeds, nuts, berries and, rarely, insects.
These handsome animals lay their eggs in tree hollows located even 50 m above ground. Some parrots prepare the holes themselves, others inhabit empty hollows made by woodpeckers, or look for ones that were formed naturally.
Parrots tend to live for a very long time, but their average lifespan depends on the species. Budgies usually live for 7 to 15 years, which is the shortest lifespan among parrots, while the blue-and-yellow macaw lives the longest – up to 100 years.
The oldest living parrot is a blue-and-yellow macaw called Charlie that resides in the UK. It is allegedly more than 100 years old and apparently, many people claim it has been Prime Minister Winston Churchill’s favorite pet. Despite the frayed feathers on its tummy, the old bird is coping well; probably, it is still feeling young at heart.
Parrots are extremely intelligent birds. Some species can imitate sounds – be it a mechanical, a human or an animal sound. The African grey parrot can even attribute meaning to some of these sounds.
Alex used to be a great star – the parrot could understand and use 150 words, count to five, and compare objects using words like „smaller”, „bigger” or „same”.
Parrots can fly, just like other birds, but it is important to remember that they evolved from animals, which used their four prehensile limbs for climbing trees. Over time, they had to undergo many changes to make flying possible.
The first step on the road to flying was growing out feathers. They evolved from scales, probably to protect animals from humidity and heat. However, it turned out the feathers make animals more aerodynamic by making the air slide along their feathered bodies.
The scientists also mention special skin membranes that proved indispensable in conquering skies. These membranes, called patagium, were stretched from an elongated finger of a forelimb, along torso and to the hindlimb. This solution enabled gliding – the animal could gently and controllably fall from a higher place thanks to the enlarged body surface. Still, it was not the same as active flying that allows to get precisely where needed.
Nowadays, gliding is used by some mammals, like sugar glider that can glide for even 55 m. Bats also have skin membranes, but they use them for active flying.
How active flight began is still not known in detail. According to some theories, animals were flapping their limbs to try running faster and thus, developed wings over time.
Others say that animals nervously flapped their limbs while falling down a tree, either to avoid danger underneath, or a painful fall.
As a matter of fact, the body of a bird is in its entirety adapted to flying. It is aerodynamic and the skeleton is light, thanks to filling several bones with air. The presence of bill is also relevant, as it is much lighter than a jaw full of teeth.
In consequence of all these evolutionary changes, birds have developed amazing abilities when it comes to moving in the air.
Humming bird is a perfect example – it can hover in the air and change its position with extreme precision (up to 1 mm). Its wings move incredibly fast, about 78 times a second.
Condor is another great flier. This bird weighing 14 kg can fly for hours without using its own muscle power.
Another interesting bird is common swift. It spends almost all of its life suspended in the air.
Due to their intelligence and beauty, parrots became the most popular pet birds. Most often, people take in budgies, cockatiels and macaws.
Parrots are not only pretty pets. It turns out they can also help people. Parrots are recommended for people who stutter or have other speech impediments. To teach parrot different words, it is necessary to speak correctly and clearly. So, while trying to teach parrot to talk, their owners may also learn themselves.
Build
To build this model, you will need LEGO Education WeDo 2.0
Explore
This construction works like a catapult and allows you to eject a small parrot into the air.
By altering the angle of the frame supporting the catapult, you can make the parrot fly further or higher.
1. Hub is the main element of every LEGO WeDo robot. It powers and controls elements connected to it, in accordance with the program created.
2. The lever installed on the edge of the catapult controls the mechanism stretching rubber bands. When the tilt sensor detects an inclination, it sends a signal to turn the motor on. If the lever is in horizontal position, the motor stops.
1. Another electronic element connected with the hub is the motor; it propels the mechanism stretching the rubber bands.
2. The long axle connected to the motor relays the drive to other parts of the mechanism, with the help of two cogwheels. Mobile arms turn around this axle.
The mechanism pulling the cart with the parrot is based on two symmetrical rack gear transmissions fixed to the mobile arms.
1. The green beams placed on the axle connected with the motor create the mobile arms. Regardless of the arms' position, the transmission is always meshed.
2. The red rubber band presses the small cogs against the cart's rack gears. It also enables the mechanism to recoil for a moment, in order to eject the parrot.
The mobile cart is responsible for ejecting the parrot forwards.
1. The axle with small cogwheels is pressed against the cart's gear racks.
2. When the cogs rotate, the cart slides on the smooth rails backwards.
3. Two yellow rubber bands get stretched while the cart is recoiling. Once the small cogs disconnect from the rack gears, the rubbers will pull the cart forwards and the parrot will fly.
This catapult model allows you to control the angle for ejecting the parrot.
1. The main part of the catapult is set on a brick with a smooth pin, so it can be tilted freely.
2. The legs, which hold the catapult at an appropriate angle, are not fixed permanently. You can stick the tan pins into one of four pairs of holes in the stand.
3. Depending on how the legs are set, the catapult will be tilted differently and the parrot will fly closer or further.
1. The parrot figurine is not affixed to the catapult, only loosely placed on the tiles. When the moving cart suddenly stops, the parrot will fly into the air.
Program
You will program the catapult in a way to enable controlling it with the tilt sensor. Put the Start Block in the programming area.
