Ch6 - Pelican
Pelicans are very distinctive birds that can reach impressive sizes. The length of their bodies can attain up to 170 cm long, while their wingspan extends to almost 300 cm. The most recognized characteristic of pelicans is their throat pouch – it can stretch and hold up to 12 liters of food.
Pelicans have long, laterally flattened bills with a downcurved hook at the end. The great white pelican's bill can reach 35 cm (females) or 45 cm (males). Together with the elastic throat pouch, the bill forms a kind of net that is extremely useful for catching fish, crabs or even jellyfish.
Pelicans are great hunters specialized in catching fish. For a single pelican, one of the methods to get a treat is to dive into the water straight from the air. However, pelicans can also hunt in groups: they position themselves in a line and hit the water surface with their wings. By doing this, they try to drive the fish to the shoal, where they can easily catch them.
Pelicans make a rather clumsy first impression. But appearances are deceiving – pelicans are highly skilled in flying and diving. They also have a special build that helps them in moving underwater: contrary to most water birds, which have only three webbed fingers, all four fingers of pelicans are webbed. Brown pelicans can dive at the speed of 140 km/h.
Our world is full of bird species that astonish us with their prowess. Besides pelican, another skillful bird swimmer is the emperor penguin, which can dive at the depth of even 265 m. The title of the fastest flyer, on the other hand, belongs to the peregrine falcon, which travels at the speed of almost 300 km/h. The Dalmatian pelican is one of the heaviest flying birds: it can weigh 15 kg. But even this species looks scrawny in comparison to ostrich, the heaviest flightless bird, which can grow to 210 cm in height and 157 kg in weight.
Build
To build this model, you will need LEGO Education WeDo 2.0
Explore
The LEGO pelican illustrates how the birds fly.
The motor propels the wings, but only when the bird is pulled backwards.
1. The pelican has a long, characteristic beak with a throat pouch used for draining water.
The torso holds in place the belt transmission, responsible for moving the wings.
1. The wings simultaneously move in opposite directions. It imitates the movement performed by real birds.
The wingspan of largest pelicans can reach up to 2.5 m.
The waving motion is possible because of the gray bricks rigidly fixed to the rotating axles.
The pelican model relies on two electronic elements.
1. The hub powers and controls the elements connected to it, in accordance with the program created.
2. The motor propels the interconnected transmissions, which lift and lower the wings.
1. The motor propels the robot via a gear transmission. The cogwheels' teeth facilitate meshing of the mechanism.
2. The transmission is running only when the pelican is pulled backwards.
3. A handle is attached to the rotating axle, in order to facilitate repositioning the pelican.
1. Lifting and lowering the wings is possible thanks to the belts. A belt drive is a construction of two pulleys connected by a belt, or in this case, a rubber band. Here, the belt drive is used to transfer propulsion from the axle to the wings.
2. The first wing moves in the same direction as the powered axle.
3. The other wing moves in the opposite direction. This change is caused by the crossed rubber band.
1. Because of the transmission applied, the pelican model looks like it is flapping its wings.
2. Birds often rest while in the air. When you move the handle and disconnect the drive, the model will imitate a pelican while gliding.
Program
This is the Start Block. It will mark the beginning of the pelican's program.
