@greatninja3 No, they need both experience and a large mana pool to pass the test. Experience in knowing the environment to not get hunted, knowledge in the monsters they face and their target, knowledge on how to capture the target with what you have and strength to be able to execute that plan. Every single mage in here have large mana pools because they all strong mages, and only Fern and Frieren were capturing birds with their specialty of mana suppression, afawk. None of the other mages were bothering with hiding their power, and a few were able to capture the birds regardless.
And must i remind you again that Frieren got instantly detected the moment she stopped suppressing her mana, meaning the mages can and will detect even trace amount of them.
@Narha Exams are not meant to teach you, they are meant to filter out the capable from the useless. They chose to enter this exam lacking knowledge and skills to survive, so of course they would get wrecked, and if you fall into a trap, well, your fault you didnt detect it, the demons wont give you second chances. In addition, you don't get to have all the cards you want when shit hits the fan anyways, especially in wartime. It's always about obtaining the objective with what you have. Just look at Frieren's party, if all of them were alone they would have had a low chance of capturing a bird by themselves, but by 1. freezing the middle lake, 2. poisoning all other water sources with mana and then 3. using Frieren's ridiculously niche spell to capture birds were they manage to pull off, despite being a team that doesnt really have easy means to capture their targets