Survival and Productivity on Laysan

April 22 – May 5, 2013
Michelle Wilcox

Photo 1. Masked Booby with chick on Laysan Island May 2013. Photo by Michelle Wilcox.

Photo 1. Masked Booby with chick on Laysan Island May 2013. Photo by Michelle Wilcox.

Here on Laysan, survival and breeding productivity are two of the main pieces of information we are documenting for the Millerbirds translocated in 2011 and 2012.  Our observations show the birds surviving and reproducing admirably.

We have been on the island just over a month and have hopefully gotten eyes on most of the banded Millerbirds.  When we left last fall there were 48 banded birds, and now 46 of them have been seen again!  This includes both adults and juveniles, which means the survival of both old and young Millerbirds on Laysan was amazingly high over the winter.

As for productivity, there are new Millerbird chicks to report.  We have three nests full of newly hatched chicks begging to be stuffed full of green caterpillars, spiders, and flies which they will turn into body mass and feathers.  We also have two new fledglings, for a total of 11 fledglings this season, and another seven nests with eggs being diligently incubated by parents.

Nature Sighting of the Week

Life is making new life all around the island, and so our nature sighting of the week goes out to all the brand-new living things.  The Masked Boobies patiently incubating eggs tucked under their feet have been rewarded with new babies.  The newly hatched chicks have white plucked-chicken skin with a black bill larger than their skull, along with clown-sized feet.

The Great Frigatebirds have been sitting on messy stick nests atop naupaka shrubs, and their single eggs have been hatching too.  They rarely let me get a peek of their white-billed baby, and if I get too close they move their head left and right slowly like a banking bi-plane. At the same time, they constantly clack their bills together as though I'm being shelled.

Photo 2. Monk seal with pup on North Shore of Laysan Island. Photo by Andy Bridges.

Photo 2. Monk seal with pup on North Shore of Laysan Island. Photo by Andy Bridges.

The monk seals have been pupping as well, and we have seen up to 10 moms with pups basking on the beaches of Laysan.  We give them a wide berth because they are an endangered species whose numbers have been declining.  In addition, there is a danger of the moms hurting or leaving their pup if we disturb them on their restful beach.

There is a nest of Laysan Finches in the bunch grass in front of the kitchen tent in camp.  The three nestlings are well-feathered and make a racket of begging when the adults bring food.  White Tern chicks have been hatching as well. I saw one yellowish chick that was smaller than a tennis ball and had its bill open and stick-wings spread as though threatening to swallow me whole if I came just a little nearer to the rock he was hatched on.  His lovely white-feathered parents were nowhere to be found, probably out foraging for silvery fishes to slide into that open gape.

Our year-round residents, the Laysan Ducks, have been attempting to increase their numbers, with 18 new ducklings seen vacuuming up brine flies at the lake's edge.

Other Bird News

The Laysan and Black-footed Albatross chicks have started to grow their black wing feathers over the last few weeks.  Some of the Sanderlings are starting to molt into their breeding plumage, and we have seen a total of 21 recently.  We have counted four invasive Cattle Egret adults on the island, but fortunately have not found another nest.  Bulwer's Petrels have begun to arrive and bark at each other.

We continue to see Pacific Golden-Plovers, Ruddy Turnstones, Wandering Tattlers (decreasing in numbers), and Bristle-thighed Curlews.  Sooty Terns have been performing aerial swarming, and Gray-backed Terns have been seen in good numbers, some sitting on eggs.

Check back in two weeks. We hope to have more good news about the Millerbirds to share with you then!