Now, such practices have been abandoned (Not Completely). But for Christian Ibans, these rituals are adapted to fit their religion.

For example, substituting traditional ritual practices with Christian practice of prayers and sprinkling of the holy water.

Source: https://ibanpedia.wordpress.com/2011/07/25/ibans-culture-and-belief-system/

such as a belt, armlet and anklet made from silver and a headgear

decorated with hornbill feathers. 

If a person is going fishing, they cannot say they are, as they believe they will come up empty.

2.) Foretold tragedy; a particular bird if chirps, they return from the jungle as they consider it to be bad luck.

3.) Bloody house; they sacrifice an animal for blood before starting any project.

4.) At attaining maturity they again draw tattoos as a way of showing great spirit of their warrior ship.

5.) In customary marriages, they pay a fine to avoid any calamity.

6.) If this couple had blood relations, they shower themselves with the blood of animals in order to avoid any  disasters in the family. 

7.) They also believe that if it rains when it is sunny, the death spirits, ghosts and giants hunt humans. 

8.) In this tribe, they believe they have a supernatural job, as a head hunter. In which, they cut off an enemy's head, hang it infront of their houses to show bravery and greatness. They even offer the head food and have a few rituals as they believe it to be alive. 

 

The boys in the Iban tribe will have their marriage arranged when they reach about 22 or 23 years old as they are considered matured to start their own family.

 

The Ibans believe that whenever it rains while the day is sunny, it is the moment for death spirits to go out hunting for humans.