Having a teacher is of great benefit, so if you have access to someone, indenture yourself if you have to. I have practically no experience. This article will be about what little I know, and what I look up.
Goal Parameters: (there's a better word for this)
|Slingshot||Unlimited ammo. Very simple and compact.||You may injure the critter, where it gets away but dies slowly.|
|Blow Gun||Very Simple, but what about accuracy?||Very long, unwieldy tube required for speed and accuracy? Limited range?|
|Slingshot Bow||Very simple and compact.||Not as accurate as regular bow, even when the slingshot has a wrist brace.|
|Takedown Arrows||Regular arrows are too long and aren't practical being carried along dense trails.||In order to fly straight, An arrow should be uniform along the length. Takedown arrows have very poor accuracy.|
|Takedown Bow||I love archery||Shooting with a bow requires skill, and I have no experience in shooting moving targets or estimating flight path over distance.|
|Compound Bow||Better performance than regular bow. Really gorgeous.||Too bulky. Also heavier than regular bow. Although some more expensive bows weigh only 3 lbs despite high strenght pull. There's no such thing as a takedown compound bow.|
|Crossbow||More accurate than a slingshot. More accurate than a bow because it reduces the imperfection of human movements.||1) Less accurate over longer distances, in part because of lesser kinetic energy of shorter arrows. 2) Crossbows are really heavy for some reason: “Crossbows are heavy, even those that start off at a mere 5.9 to 6.9 lbs, once they are outfitted with a scope, rings, sling, quiver, arrows and miscellaneous…” source Some weaker, lighter ones start at 4-5 lbs, but they will have less accuracy due to the slower arrow. 3) Crossbows are almost as bulky as compound bows. There are a few low-powered takedown crossbows, which make them stowable. Some very expensive compound crossbows that are $1000 and up are made narrow and thus better stowable. Even more so if the gunstock were detachable (or extendible) to reduce the overall length.|
|Air Gun||Accurate.||Loud compared to archery or darts, although less so than a regular gun, and a silencer can be used to further reduce the blast. “Another nice benefit to owning a good survival air rifle is that you can purchase them online with zero restrictions. They are not regulated by our nanny government so you can buy as many as you want today with no hassles.” skilledsurvival.com|
|Pipe Gun||Does not look like a gun. Doesn't weigh much or take up a lot of space.||Very Loud. Firearm regulations. Regular ammunition with gunpowder.|
If you are backpacking with your cat, this is not an option.
The lightest weight traps are those you make with rope, tree branches and rocks. I found a good tutorial online that I will learn from:
Another light option are snares:
The smallest professional trap in USA is the DUKE 110 BODY GRIP TRAP. It measures 114mm x 114mm and is pretty heavy. You are unlikely to find an ultralight titanium version. Even though it is the smallest version from Duke, this trap is tough to spread and dangerous to handle.
You can find traps that weigh less on ebay or aliexpress. The springs are not as strong as on the Duke trap.
The lightest body trap option is the Victor M326 Rat Trap. You can increase the strength of the trap by placing a spacer between the spring ends and the wood (the two ends in the middle of the trap), as seen in this article. They are incredibly effective near shelters along the Appalachian Trail. Bon appetit!
Wikipedia covers different fishing techniques:
Hand gathering: Depending on location, there are shellfish and crabs that are easy to gather.
Spear fishing: If you can see through the water, a spear can be used, such as your trekking pole.
An ultralight and compact fishing pole would be a carbon fiber pole and mini reel. A 1.5 meter telescoping pole compacts to a length that fits even in a day pack. Pole fishing can be fruitful, but it is more of a sport. To have a better chance of success, you can use longlining, nets, and/or traps.
Longlining involves running a heavy fishing line between two visible bobs such as empty plastic bottles. From the heavy line running along the surface, you run individual lines (snoods), each having a bob at the top and a weight and baited hook at the bottom. You leave this unattended, so it is better to have this at a lake rather than a stream, unless you can find a way to secure one end from the middle of the stream.
This can be difficult to set up without a boat. However, you can swim out with the heavy line and two bobs, and a bag with the snoods inside. Each snood has its own bag within the main bag to avoid tangling. The snoods have a clip to attach to the main line.
A gillnet or driftnet may be the most compact UL net option for catching fish. It catches fish when they unknowingly swim into it. If the fish is the right size, it will be too big to swim through, but have its gills or fins get caught in the net. The floats can be bladder-bottles or dry-bags, and the weights can be stones. You can throw some bread crumbs to attract fish to the area.
A lift net sits at the bottom of shallow water, while some food lures fish to swim above the net. Lift nets can be folded into a long slender piece.
If the water isn't very deep, you can make a trap from whatever is in the area, either sticks or stones.