When you first see a deer, you tend to get tunnel vision and go into autopilot. This can be good and bad. If you've practiced with your gear, techniques, positioning, are a good shot, etc, instinct kicking in is great. The problem is that adrenaline has a way of warping your perception of a moment. The one advantage we have over most critters, is that there's "something it's like to be you." You're aware of this issue and can address.
When you get in position to make a shot, do your best to make a snap assessment of where the deer is standing. Next, focus on where you intend to aim and take your shot. Follow through after the shot - this is really hard with a scoped crossbow. It's almost impossible not to blink at the shot, and an arrow doesn't travel as fast as a bullet. By the time your eye opens, and refocuses, it's too late to see impact. I'll be writing a post about this topic later... But do your best to hold on target through the shot. If you can keep your eye on the deer as it runs off without moving from the position you shot the deer, do that. I'll tell you why shortly.
Now watch the deer's reaction to the shot - try to remember if it ducked, stood still, if you heard a hit, didn't hear a hit, did it jump up and mule kick, did stumble before taking off. Then DO NOT take your eyes off the deer until you physically can't see it anymore. Make a positive landmark in your head of the last spot you saw the deer - use a tree bush log whatever - something that the deer ran/walked within 5 yards of on it's way out of sight. Say it out loud if you need to - point at it with your finger if you need to - grab your compass or phone and get a compass bearing if you need to. Remember this - it will look completely different at ground level than it did from 20' in a tree. Your ears are designed to hear best in the same direction you are looking. Listen intently for crashing, walking, wheezing, gurgling, any noise that could give indication that the deer is alive and moving or dead and dying. Give that at least 30 seconds to a minute. Hopefully you haven't moved from shot position.
Turn your head back to address the spot the deer was standing when you shot. Recreate the shot with your bow. Find the EXACT spot you remember the deer was standing when you shot. It is extremely helpful to be in the exact position you were when you shot. Say it out loud if you need to. Point to the spot the deer was standing. Find a landmark - this one should be easy since it's so close. But remember, it will look different than ground level - this is why you MUST have a landmark. It can be a leaf or stick or bush or anything. If you have a rangefinder, range the exact distance to this spot.
For shots that you have no idea where you hit, and didn't see or hear the deer crash - And don't worry, shoot enough deer, this will happen, no matter how calm and collected you are.
Assuming there is no time pressure due to incoming rain, etc, If you can get out of your tree without making ANY noise, go ahead and get down. Remember, fatally wounded deer do not like to keep moving. There's a good chance the deer has bedded in eye/earshot of you. Get down quietly, pack/organize your gear for walk out/tracking. If you are concerned you might not remember the tree you shot the deer out of the next day - mark it somehow. Trail marker, toilet paper, something. If it is really crunchy or really still, I highly recommend sitting at the base of your tree for at least an hour. If it's wet, or you have wind cover, or you've waited an hour or so, walk in the most direct line you can to your shot location. If you ranged it, or have a best guess, go very carefully the last 4-5 yards. I prefer to step to the opposite direction the deer was facing a couple yards, and then advance, looking in the line of my shot. This is so I don't step on their tracks, cut hair, blood, arrow, etc.
Impact site can tell you a lot. Hopefully you find a bloodsoaked arrow. If not, but you hit the deer, you're almost always going to have cut hair at the shot site. I recommend the next deer you or a friend kills, you cut hair from various parts of it to inspect very closely. Take pictures even. You want to be able to identify what part of the body the cut hair came from. Look for the deer's prints where it ran from the shot site. Many times you can see where the dug in when they duck/run. I like to stick toilet paper or twigs standing up if the leaves are thick, in the prints. Now I can see where the cut hair is in relation to the prints. I can also look back at my stand tree to see the exact angle the deer was at. Write down, memorize, take pictures, whatever, but make note of all of this information.
If you don't find your arrow, and you don't know where you hit, and you don't have weather forcing you to speed up your search, LEAVE. Put a piece of toilet paper, an arrow, a glove, something at the shot site. You've already marked your stand tree. Now mark your trail out for ease of access coming back to the site. If the deer ran in the direction you have to leave, attempt to take a wide berth around where you think it went. A few hundred yards will suffice. Otherwise, take the fastest direct route to get out to access.
There's dozens of articles, and even good books on what to do with certain hits. I'll leave that to what's already written. Flat out - if you don't know where you hit the deer, it's cool enough it won't spoil, you have no rain coming in, coyotes aren't a problem (this is usually not a problem. You'll know if it is. Don't let the myth of the coyote scare you - you will know if your locale is one to be concerned about, trust me.) - LEAVE THE DEER OVERNIGHT. As has been said before, don't go try to find your deer at graylight. Wait until you have good light to search by.
One area I will push back though, is accessing the spot. If you know you won't disrupt someone else's hunt, I like to slip in at graylight to my shot site, and sit there and wait for better light to track. First - less chance of deer spotting me. Second, better chance of having dew/humidity making leaves slightly less crunchy.
It should go without saying at this point - but if you have access to a TRAINED blood dog, and experienced tracker, call them. This should not be a point of pride. And watching a dog find your deer can add immense satisfaction to the results of a hunt. Trust me - it's almost as fun watching a good dog work, as it is killing deer. I'm not the only one who thinks this - there's thousands of trackers who do it for gas money or free - instead of hunting.
If you don't, get to tracking. Again, lots of writeups on how to track, I can't tell you any better. Do your best to find blood or tracks on the course you think the deer took towards the spot you last saw the deer (you remember this spot right?). Slowly make your way, marking any blood or tracks along the way. If you haven't found the trail by the time you arrive at the spot you last saw the deer, this is your last real chance to pick up the trail easily. You KNOW the deer was within five yards of this tree, vine, log, stump, bush, etc. Hands and knees until you find blood.
At this point - you have endless resources on how long to give deer if they're shot a certain way. Plenty of resources on how to track deer. I can't help anymore than that.
But the above things are crucial information in determining where you hit the deer, and what to do.
Highlights:
- Follow through on your shot.
- Remember exactly where the deer was standing when you shoot.
- Try to stay in shot position to confirm this.
- Watch the deer the whole time until it crashes or goes out of sight.
- Listen intently without moving for at least a minute after losing sight.
- Mark a landmark at the very last spot you saw it.
- Recreate the shot to mark the exact spot the deer was standing when you shot.
- Wait an hour to leave the shot sight if you can't leave without being heard.
- If the deer ran in the direction of access, try to give it a wide berth.
- Mark your stand tree.
- Mark your shot site.
If you want help from experienced hunters on internet, or mentors, or friends, or trackers, have the following information. I find it best to write it down if you're new.
- How high you were in tree.
- Distance of the shot.
- Angle of the deer.
- Where you think you hit the deer.
- How the deer reacted at the shot.
- Sound of impact (heard one, didn't hear one, what it sounded like if you did).
- How far it ran/walked to where you last saw it.
- If you heard it running or walking beyond where you lost sight.
- Tail up or tail down.
- Pictures of arrow if you recovered it.
- Pictures of hair at shot site if you recovered it.
This is a ton of information to try and take in. But your body and brain is amazing and will capture it if you've prepared yourself prior. And all of it will help you be more successful in recovery efforts.
Sorry for the long read, I hope you gathered something useful. And I have no doubt this will have been a useful learning experience for you. Keep your head up. These types of things happen to every hunter.