Shalmanese: Yep, that’s it.
The only time I remember seeing a bird, it was being chased downhill by a man shooting arrows at it. Flighted arrows might have helped. But the idea that you could shoot a pig with a lighter arrow just shows how out-of-touch typical anthropoligists in PNG were.
Hm, makes me wonder if they were using the bow and arrows that I had a version of - the arrows were flightless, and 4 foot lengths of what looked like finger diameter bamboo with the point shoved into a split that was about 3 inches of tube back to the joint, glued in with some sort of sap and wrapped with sinew. [Gift from some missionary buddies of my Grandparents who were doing the New Guinea thing back in the 30s. I also ended up with a blow gun, and quiver with attached gourd of some sort of fluff and tube of curare from somewhere along the Amazon other than the Huaoranis though my family did know both Elliot and Saint.]
Pig arrows would be pointed with a broad piece of bambo - sort of like a symetrical knife blade. Bird arrows would be three narrow bambo points spread, looking like the end of a fish spear.
People arrows, the kind casually carried around by men in the same way that some Americans casually carry around a gun when not hunting, for the purpose of shooting someone if they feal like it, would have a long hardwood tip the same diameter as the shaft, patterned with natural pigments, barbed forwards and backwards by carving the wood.
The hand carved and decorated arrow points show personal as well as regional variation, and since they were open-carry, we can assume that people cared about the appearance.
Many ancient (Prehistoric) arrows have remnants of fletching glue on them. The most common source of glue in Northern Eurasia, where most ancient arrow finds come from, is birch tar and pitch glue (both waterproof). Arrow fletchings were typically also tied down, sinew thread and strips of (waterproof) birch bark being the most common material here.
The problem with only-tied fletchings is that the center of the feathers starts to lift off the shaft due to changes in humidity, which messes up arrow flight, increases noise and looks hideous. Glueing the feather quills down solves this problem. Tying the quills down through the vanes with thin thread, barber-pole-style, is also an option.
Many cultures in the world used unfletched arrows, as fletching is a bit of pain in the ass under field conditions. These arrows were (obviously) designed to fly well and accurately without fletchings, something alien to Western target archery. Here’s a report from Papua New Guinea that illustrates how unfletched arrows perform. I’ve always suspected the funny story mentioned in a previous post about PNG tribesmen learning about fletchings. The linked article shows unfletched PNG arrows taking down big game animals at 25 yards or more, something any trad archer using fletched arrows would be very pleased with.
Also, bowstrings most definitely do not need “elastic spring for best function”. Elastic strings only waste energy that would otherwise go to the arrow. The less spring a bowstring has, the faster, more powerful arrow it propels, tried and true, time and time again.