I am under the impression that the crabs would make sleeping on the ground difficult if not impossible.
Not impossible, but at least in our experience the crabs are definitely an issue to be dealt with.
Would a fire(s) keep the crabs away? It would be lots of work, but maybe worth it. This maybe an explanation for the multiple fire sites. What spacing would exclude crabs? Are the fire sites in any sort of pattern?
There are not as many fire sites as we initially thought. We were counting every occurrence of charcoal as a separate fire feature but many of those may represent nothing more than a burning stick that got separated from a larger fire. Also, analysis shows that bird and fish bones from some fire sites are more in line with islander practices. We currently have just two fire features that appear to be castaway-related.
The crabs do not seem to be intimidated by fire. I should be clear that the crabs we're talking about are the little Strawberry Hermit crabs, not the big Coconut crabs (Birgus latro). Everybody tends to focus on Birgus latro because he's big and scary looking but he's usually quite shy. He'll defend himself if he feels threatened but I've never seen him behave in an aggressive manner. The observed behavior of Strawberry Hermits in the abandoned village is similar to Coconut crabs - shy and retiring. Strawberry Hermits at the Seven Site, oddly enough, are a different story. They're bold and aggressive, scuttling out of the underbrush as soon as they sense (smell?) the presence of food. Every time we broke for lunch they appeared by the hundreds, foraging around our feet, climbing up table legs, or pant legs, looking for goodies. They're not fast and their pincers are small, but they will tear a little chunk out you if they get the chance. Lie down on the ground and you'll soon have a regiment headed your way. I recall only one occasion when a Coconut crab came to lunch and he did not come out among us. He lurked on the edge of our lunch area and seemed most interested in a plastic replica of a human clavicle (collar bone) that one of the team members had brought to the site for comparison purposes. I named him Clavicle. We later discovered that he lives in a burrow inside a hollow tree trunk in the buka forest about two hundred meters north of the Seven Site.
It seems reasonable to assume that the castaway did not have/create a tent or other structure to exclude the crabs, although it might have been possible to create some kind of wooden stockade with a lot of work and probably tools.
One of the big mysteries of the Seven Site is the presence of a considerable quantity of small rusty fragments of what appears to have once been corrugated iron. Our current thinking is that it was probably a stockade around a coconut nursery associated with the abortive planting at the site dating from the early 1940s. Protecting young plants from crabs by surrounding the nursery with iron is mentioned in the island literature. The source of the iron corrugation was probably the old Arundel workers shack at the west end of the island which we know from Arundel's notes was sheathed in iron sheets. It's theoretically possible that the corrugation was brought there by the castaway but that stuff had to be heavy and moving it all the way down to the Seven Site seems like more than a castaway could manage.
The coconut crabs can climb trees, making sleeping in a tree crotch undesirable.
It seems unlikely but not impossible that she was able to make a hammock. The tie down ropes (if not lost) plus some fabric or even palm leaves might do it. This might be the best solution if the materials were available. It would have been tried first at Camp 0. if it existed, it was probably lost/scattered/destroyed in the logging.
Hammocks do work pretty well. Jim Morrissey (AE's great nephew) was on our 2001 team. He made a hammock out of a fishnet he found washed up on the beach. It should have been possible for AE to construct a hammock from tie down ropes and the "Grenfell cloth" engine covers listed in the Luke Field inventory - if they were carried on the second world flight attempt and if they were brought ashore and if they made it all the way down to the Seven Site.
Haven't I seen a reference to a small islet in the lagoon near the Seven Site? If it exists, would that not have been an ideal sleeping camp? Coconut crabs cannot swim. A good site to look for artifacts.
Hmmmm....now that you mention it, the ONLY such feature that I know of is a big coral rock near the lagoon shore not far from the Seven Site. I've never thought of it as a possible place for a castaway to sleep and it sure wouldn't comfortable - but neither is getting nipped by crabs. I don't think any of us has ever waded out and climbed up on it - but I'm suddenly eager to do so.