July 9 – July 22
Just when I think I have a good handle on the behavior and ecology of the Millerbirds, they throw me for a nice loop. The most exciting part of the last two weeks is that the birds have decided to start nesting again. Apparently they just needed a quick intermission to molt in some new feathers before raising some more chicks. I found one new nest this week, as well as seeing another pair with nesting material, and many of the pairs have become much more vocal again in the past week. Similar to most species, Millerbird breeding is resource-dependent. Millerbird numbers on Nihoa are thought to be close to the island’s carrying capacity, but here on Laysan, with so few birds on a much larger island, plenty of room and food are available for them to spread out and raise young ones. Both pairs re-nesting so far have only raised one successful nest this spring and summer, but for some pairs, it could be lucky number three if they decide to try again.
The “Resight of the Week” is a pretty easy one this time around. The female O/W, O/S is by far the most difficult of the paired birds to find. This is only the 13th time she has been sighted in the ten months she has been on the island. It had been 80 days since I was last able to get a good look at her bands, and the resight was even better since she was in the process of grabbing some nesting material off the ground.
Around the island, much is going on at the moment. Albatross young continue to fledge, and the island has begun to empty of them. Quite a few other species have young that are starting to fly and become independent as well, including Red-tailed Tropicbirds, Masked and Brown Boobies, and Sooty and Gray-backed Terns. The first tiny chicks of the Bulwer’s Petrel have been seen, as well as many Brown Noddy chicks. The Christmas Shearwater (another tubenose) also has chicks, with some beginning to come out of the grass-covered burrows where they were born: dark gray fluff-balls with heads too small for their body (or bodies too big for their heads?). Some of the larger chicks already have the distinctive Mickey Mouse-like calls down pat.
Other than that, the only noteworthy sighting was of a group of three Blue-gray Noddies at the south rock ledge. Rocky cliffs (the preferred habitat of the Blue-gray Noddies) are scarce on Laysan, with only this area in the south being of any substance. No indication of breeding has been seen, but we are keeping an eye on them.