And now for something completely different

I've been back from the Cook Islands for over a week now, and despite the fact that I had easy Internet access there (including wireless access points in downtown on Rarotonga, and at the airport!), I never posted again to this blog. The Cooks had been described to me as a "parallel universe" to French Polynesia, by which my colleague meant that the main island of Rarotonga looks like a version of Mo'orea where people speak English and drive on the left. But the differences between being a British, and then New Zealand, territory, and being a French territory, are more fundamental, and the experiences I had in the Cook Islands were in many cases completely unlike the experiences I have had throughout French Polynesia.

I started out on Rarotonga, where I stayed in a hostel. This was bizarre. Usually on remote islands in French Polynesia, I stay in guesthouses. Hostels cost about a third to a fourth what a guesthouse does, and they are full of English-speaking budget tourists (Brits, Kiwis, Germans) on gap year or something traveling around the world trying to make friends everywhere they stop. It is pretty weird returning from the field in the afternoon and finding a bunch of Germans watching The Downfall (about Hitler's last days) in the common room of your hostel. You don't want to be antisocial, but you have field notes to write up, specimens to curate (why is the American guy putting plant leaves and alcohol in little plastic bags?), and tourists you want to discourage from accompanying you out hiking the next day.

Rarotonga was a really easy place to do fieldwork, thanks to the excellent efforts of Gerald McCormack and the Cook Islands Natural Heritage Project, who have maintained excellent walking tracks (er, hiking trails) on the island, written two detailed guidebooks about them, and produced a great biodiversity database. Sadly, I hit Rarotonga at a time when the Glochidion trees were not reproducing much--I was only able to find two trees with fruits, and none that had female flowers! This means I have just barely enough moth larvae for my thesis, and without female flowers, I will need to use DNA to figure out what the affinities of this Glochidion species is. To date it has been considered the same as a species found in Fiji and Tonga, to the west. Rarotonga is only about two million years old, much younger than the neighboring Austral Islands and Leeward Society Islands (but about the same age as Mo'orea, and older than Tahiti); consequently, it is thought that the plants at least may have come from French Polynesia. My research will be able to address this question, for at least a few species.

The wet forests on Rarotonga are in excellent shape compared to everywhere else I have been--they are dominated by an odd mixture of tree species, notably mato (Homalium), a majestic, multi-trunked tree which is found in the Australs but not the Societies, and neinei (Fitchia; see photo on blog post below from Rapa), an odd tree with huge thistle-like flowers and prop roots that is extremely rare in the Societies, common on Rapa, and absent from the northern Australs. To make a sweeping generalization, at lower elevations in French Polynesia the overstory is invaded by exotic trees and whatever native stuff is left is in the understory; on Rarotonga, the overstory is native, and the understory is full of exotic shrubs. To top it all off, the Cooks have held on to a greater proportion of their native birds, including huge fruit pigeons in the genus Ducula. These are important seed-dispersers for native plants, but in French Polynesia have only survived on two islands, Makatea and Nuku Hiva. Likewise, Rarotonga has a native starling, likely a pollinator of neinei; it's much rarer, and I felt very lucky to have seen one on my last day in the field there. (The Cooks also have fruit bats, which French Polynesia lacks, but they are extremely rare and secretive because they are still hunted. They may also have been introduced by the Polynesians.)