Island Biogeography: a fascinating subject, and what better place to study it than in the archipelago of the Republic of Fiji?
Cohort BL Padgett and I took the Subduction Recon Team out of the frosty subantarctic to the sea-breezed equatorial isles of the South Pacific this last week. Fiji is a collection of volcanic islands, calcareous paleo-reef mounds and subducted & uplifted oceanic crust.It truly is another world.
Pumice, a not-at-all dense igneousvolcanic rock, FLOATS between volcanic and reef-born islands that are so young and rumbly that their flora are still dominated by early successional shade intolerant species. Being an archipelago of isles that vary in origin, size and topography, it perfectly elucidates the principles & mysteries of island biogeography...plus, it's tropical paradise.Most islands have no standing fresh water and the resources and living space are of such paucity that dispersal and establishment of biota on these isles is a rare event, but there is one phylum of Animalia that has perfected such acts of dispersal heroism: Arthropods. Namely, the Insecta, Chelicerates and Myriapods. Flocks of Lepidoptera, man-eating spiders, and centipedes that tunnel through the sand and bite Luke's feet. Here are a few pics of some specimens we encountered.
The Fiji isles are also an example of another phenomenon associated with biogeography on small islands: the trend towards gigantism. Both these spider species were the size of my palm. We found a web spun by the species with the white abdomen that measured literally 20 ft across! Perhaps the best example of this trend towards gigantism is the Fiji Walking Stick, one of the largest insects in the world (over a foot long!!!). Sadly, we didn't encounter this fella. Oh well, it's just an excuse to go back and find it.
Oh, Padgett and I also made a raft (see bottom pic).This concludes the Oceania posts. Oceania is truly a mystery, and it holds the key to much that we do not yet understand about our natural world. Here's to Wombats, Moas and Giant Walking Sticks, and all things historically natural!
EM
"To live would be an awfully big adventure"
