You can save rare hunts for later in Monster Hunter Wilds, so you can come back for that Rey Dau gem when it's convenient
Once you progress far enough in Monster Hunter Wilds, you'll be let loose into the world to knock out back-to-back battles with Lala Barinas and Balaharas in seamless hunts served up by shifting monster spawns. Unfortunately, not even ace hunters can be in two places at once: Your friend might need your help with a pesky Ajarakan just as an Uth Duna appears on your map with a guaranteed plate as one of its survey rewards. Luckily, you don't have to miss out on rare monster parts if you can't immediately jump into a choice field survey: In Wilds, you can save hunts from the World Map to tackle later when you've got time.
To bookmark a monster on the world map for later hunting, move your cursor over the monster on the map and hit A on an Xbox controller (F on keyboard) to start creating a quest. Hit A again, and choose "Save as Investigation." Rather than immediately starting a field survey hunt, this will create a quest that you can start later from the Investigations section at the quest counter while talking to Alma.
Saving a field survey as an investigation isn't free: It'll cost you a few hundred Guild Points, with higher tier and tempered monsters costing up to 600 points. But if you're regularly hunting, the cost shouldn't be an issue. I've been saving investigations constantly since I noticed the feature, and I've never come close to running low on guildbux.
Being able to save investigations is particularly valuable in High Rank once monsters on the world map start offering randomized bonus rewards from their field surveys. If I notice a Rathian with a guaranteed ruby in its reward pool that I need for a weapon upgrade, I can stash it in my investigations and hunt something else without losing that gem.
Better still, you can attempt investigations up to three times. If you're looking to make the full Xu Wu armor set, you aren't forced to wait for them to spawn naturally. If you've saved an investigation with a healthy set of material rewards, you can run it three times in a row for a pile of parts.
You can even save a field survey as an investigation after you've hunted the monster. Talk to Alma to post/join a quest as usual, and then choose the "Field Survey History" section. There, you can see the last 16 monsters you hunted in the field, and you can save any of those field surveys as an investigation. This will then give you the full three investigation attempts. That means by hunting a monster with rare rewards and then turning it into an investigation, you can hunt for those rewards a total of four times. That's a lot of Rathian Rubies.
You can't go too wild with saving investigations, because you can only save up to 50. For most of you, that shouldn't be an issue. Me, I might have an issue with hoarding Tempered Rey Dau that needs some working through.
Monster Hunter Wilds guide: All our advice in one place
Monster Hunter Wilds tips: Hit the ground hunting
Monster Hunter Wilds weapons: Builds galore
Monster Hunter Wilds best armor: Defend yourself
Monster Hunter Wilds monsters: All the beasties
Monster Hunter Wilds multiplayer: How to co-op hunt