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.

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.

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!

Flurry of Activity on Laysan

April 8 – April 21, 2013
Megan Dalton

One of five Nihoa Millerbird nestlings banded so far this 2013 season on Laysan. This chick was banded Y/R:BK/Y (yellow over red on the left leg, black over yellow on the right leg) at approximately 13 days old.
Photo credit: Megan Dalton

My first month on Laysan, where I’m helping to monitor the recently reintroduced Millerbird population, has been a bit of a whirlwind. So many new sights and sounds to take in and places to explore on this island, while simultaneously trying to get settled into camp and, most excitingly, jumping right into our Millerbird monitoring tasks.

It’s been a challenge to catch up on all the Millerbirds’ movements, pairings, and activities since the field crew was evacuated last fall, especially since there appear to be many more younger, unbanded birds in the area trying to stake out their own territories amongst the older, more experienced birds. A rather pleasant problem to have with this recently translocated population – more Millerbird activity than we can handle!

Millerbird breeding wave:

While it is impossible to say for certain, we think we arrived at the beginning of a new breeding wave. Males have been busy singing their energetic songs and both sexes have been observed carrying nesting material, such as grasses and seabird feathers, to their nest sites. Certain pairs were already carrying food items to their nests, indicating that their eggs had already hatched and that they were feeding one or more nestlings! So far we have found 11 nests and have confirmed 9 successful fledglings. Several pairs are currently incubating eggs, so we expect that number will increase soon. An auspicious start to the breeding season for sure!

Michelle and I were also able to participate in a first for this project – banding nestlings at the nest – which was both extremely thrilling and terrifying at the same time. We took every precaution in doing this safely since, as with many passerines, there is potential to cause the nestlings to prematurely fledge. There is a small window of opportunity between when the young birds’ legs are the appropriate size for banding and when they are still sedentary in the nest. (They get jumpier as they get older!)

We are happy to report that the five nestlings we have banded all stayed in their nests like good children and successfully fledged 4-8 days later. They will continue to be fed by their diligent parents for a month or so while they learn how to make it on their own.

Nature sight of the week:

A pair of Wedge-tailed Shearwaters, caught in a quiet moment. Photo: Ian Thomas

It’s been hard to ignore the calls of the noisy Wedge-tailed Shearwaters. I think they’ve been aiming for their chance to be the ‘Nature Sighting of the Week’ feature on this blog. Okay, wedgies, you win, here goes. The Wedge-tailed Shearwater is a long-lived, medium-sized pelagic seabird that feeds on fish and squid at the surface of the water. These birds return to low, sandy areas at this time of year where they dig nesting burrows in the ground and will eventually lay their one egg of the season.

The wedgies are currently in the courting and pair-bonding phase of their breeding cycle and spend much of their nights calling and moaning to each other, alternately sounding like crying babies (WAAH!) or someone badly imitating a ghost (ooooOOOOooo!). They are working hard on their burrows, some excavating new ones and others renovating old ones. Like all seabirds, the adults invest a lot of time and energy into their one egg: 53 days of incubation and over three months of feeding the slow-growing chick. If everything goes right for the chick, it can live many years. The oldest Wedge-tail on record was 29 years old!

Other bird news:

Besides the regular Ruddy Turnstones, Pacific Golden-Plovers, Wandering Tattlers and Bristle-thighed Curlews, we haven’t seen too much of note aside from a handful of Long-billed Dowitchers and Sanderlings and one lone Red Phalarope. The Short-tailed Albatross hasn’t been seen in two weeks and probably won’t reappear until the fall. The Laysan Ducks are in the midst of their breeding season, with a high count of 11 ducklings this week.

Join us again in a few days for more sights and sounds from Laysan.

Megan Dalton is a Millerbird
monitoring biologist on Laysan.

Return to Laysan

8 April 2013
Michelle Wilcox

The critically endangered Millerbird. Scientists are tracking the growing number of Millerbirds on Laysan Island. Photo: Robbie Kohley

Editor’s Note: This post resumes our series with scientists on Hawai’i’s Laysan Island in the Papahānaumokuākea Marine National Monument, where they are following up on a multiyear effort to establish a population of the critically endangered Millerbird. Two translocations of Millerbirds from Nihoa Island to Laysan were completed in 2011 and 2012, and scientists are now monitoring breeding success and tracking the growing number of Millerbirds on the island. The effort has been carried out by a team of biologists from the U.S. Fish and Wildlife Service and American Bird Conservancy.

After being closed since November, the camp on the 1,016-acre coral atoll known as Laysan Island reopened in late March and is now staffed with five U.S. Fish and Wildlife Service personnel and two Millerbird biologists.

I was lucky enough to return to Laysan Island along with Megan Dalton, the newest biologist. Together we will continue monitoring the newly translocated Millerbirds to try to determine how many survived the winter and then monitor them throughout the summer. We hope to discover how many new chicks have fledged and where on the island they are living. In the first couple of weeks, we have already seen more than 38 individual Millerbirds and are expecting to find even more in time.

Laysan Island’s human population. Back row, left to right: Andrea Kristof, Justin Yeh, Andy Bridges, Ian Thomas. Front row, left to right: Brianna Ordung, Megan Dalton, Michelle Wilcox. Photo: M. Dalton

The birds began nesting on Valentine’s Day last year, so we predicted they would be nesting when we arrived this year. The birds are indeed busy, and Megan and I have found six pairs nesting so far. Three pairs have nests with chicks in them, and three pairs are building nests. Additionally, we have found males defending new territories adjacent to the area they favored last year. The naupaka shrubland on the north end of the island appears to be the Millerbirds’ favorite area.

Although Millerbirds are our focus here on Laysan, our “Nature Sight of the Week” is the tens of thousands of Laysan Albatross chicks sitting all over the island. Their parents had just started arriving in the fall when we left, and the island is now a very different place, so much more full of life and activity. There is a grey, downy chick the size of an overweight bowling pin under my clothesline. During the heat of the day he waddles unsteadily into the shade of my weatherport platform, but he must return to the patch of ground where he hatched or his parents will not feed him with regurgitated fish, fish eggs, and squid when they return from foraging flights, which can cover thousands of miles.

Laysan Albatross chick by Mary Hughes

The Laysan Albatross do not begin breeding until around their eighth year of life, but starting at age three they begin to return yearly to Laysan during the breeding season to practice their courtship dance, to find and defend a territory (males), and to find a life-long mate. This means that in addition to the chicks and their itinerant parents, there are tens of thousands of young adults on the island who spend most of their days calling, clacking, and dancing. What a life!

In addition to the Laysan and Black-footed Albatross, there is one lone Short-tailed Albatross who returned again this breeding season to what we call the “northeastern desert.” Along the brine lake edge, we have seen two Ruff, four Long-billed Dowitchers, two Red Phalaropes, and 12 Sanderlings, in addition to the large numbers of Wandering Tattlers, Pacific Golden-Plovers, and Ruddy Turnstones. We have seen one Cattle Egret near the grove of coconut tree snags, and we have seen a good number of Bristle-thighed Curlews around the island.

We plan to post these blogs every two weeks, sharing updates on the status of the Millerbird population, stories about specific individuals, and information on all the other natural and unnatural wonders on Laysan. See you again soon!

Michelle Wilcox is a Millerbird biologist with American Bird Conservancy.

Evacuation

October 29^th-November 20^th 2012
Michelle Wilcox

Figure 1. Michelle Wilcox with a highly curious Laysan Finch (Photo by Robby Kohley)

On November 4^th all personnel were evacuated from Laysan Island, and the camp was closed for the duration of the winter season.  The problem began with a medical issue (everyone is okay), but was exacerbated by the fact that the winter season prevents boats from landing in the area.  Thus, evacuation was used as a preventative measure to ensure human safety.  The camp will reopen in March of 2013, at which time I, along with another biologist, will return with the Fish and Wildlife Service’s habitat restoration crew to monitor Millerbirds through the summer.The current wave of breeding was nearing its end with only two sets of nestlings left when I departed.  Another fledgling was added to the population for a total of 29 Millerbird juveniles produced by translocated birds in 2012.  The number of adults molting their feathers was increasing, and we suspect they will now begin their winter quiet period.  In the winter months last year, Millerbirds were difficult to detect because the birds spent this time quietly foraging in the depths of the naupaka shrubs, and the males were not singing their territorial display songs as often.  On the bright side, I would say that if there were a BEST time of the year to halt our observations, it would be during the winter.

When we return in March, we expect to find the birds in the middle of their first wave of nesting for the year 2013.  It will be interesting to see which pairs remain together and which adults move around to new partners or new territories, which young birds begin breeding before they are a year old, and which birds, if any, cannot be found and may not have survived the winter.  The birds should do fine despite the absence of their human peeping-tom neighbors.

Figure 2. The sun sets on this tour of Laysan Island, only to rise again in early 2013 (Photo by Michelle Wilcox)

My ‘Nature Sight of the Week’ goes to the ubiquitous and gregarious Laysan Finch (Telespiza cantans) (Fig 1.).  This endangered species is endemic to Laysan Island; they persisted despite the decimation of the vegetation on the island by rabbits in the early 20^th Century.  We speculate that one of the reasons this species survived when others – such as the Laysan Millerbird, ‘Apapane, and Laysan Rail did not – is that they are curious generalists.  Gangs of them are found in almost every habitat type on the island busily pecking at everything to see if it can be eaten.  While you are standing in place looking through binoculars they will hop onto your boots and start pecking at the grommets and laces.  When you stick your head into a naupaka bush in search of Millerbirds, a few finches will hop over, inches from your face, to take a look at you.  We caught this finch because he decided to investigate whether the nets we had set up to capture unbanded Millerbirds were edible.  In camp they land on the screen door of the kitchen and work on tearing the screen with their bills so they can get inside and explore for edibles.  They have also pecked holes in our propane gas hoses and made their way into personal tents where they leave ‘tokens’ of their respect.  Although sometimes annoying, they provide entertainment for behaviorists like myself.  I cannot wait to return to Laysan Island and learn more about their social system; indeed, there is so much more on Laysan to explore!

Changing Seasons

October 15- October 28 2012
Michelle Wilcox

The Millerbirds and I bid bon voyage to Robby Kohley on October 16th. While he was here, he talked a lot about wanting to come full circle with Millerbirds by capturing an unbanded juvenile that was born of parents he helped move from Nihoa Island to Laysan last year. Robby has been a key part of this project since 2009. He performed pre-translocation feeding trials on Nihoa to make sure that we could keep Millerbirds in captivity for the length of time needed to move them between islands, and then lived on Laysan for six months after the first translocation last year to monitor the birds’ survival and productivity . Sure enough, just before he left, we were able to capture a young, unbanded Millerbird that was born on Laysan earlier this year, and Robby was able to band it with his “signature” color.

Robby Kohley with a newly-banded fledgling Millerbird. Photo: M. Wilcox

Meanwhile, the Millerbirds have been busily engaged in making more Millerbirds. For this wave of breeding, we now have five fledglings and three nests with nestlings still being fed. A number of the birds that just came from Nihoa are going through a molting period, which means there are Millerbirds hopping around without tails. They look a little bit like they forgot to put their pants on. I have noticed that the resident birds that have been here since 2011 have been more successful at breeding in this wave than the newly moved birds. We have had a number of failures so far, but all by new birds.

The charter vessel Kahana that took away Robby and the summer crew dropped off the winter crew, who will be staying with me on Laysan through April. We experienced our first tsunami warning on the night of October 27 from the earthquake near the Queen Charlotte Islands, off the central coast of British Columbia. We did not see much wave action, but we did have a smooth test of our emergency procedures.

A pair of Black-footed Albatross recently arrived on Laysan. Photo: M. Wilcox

My ‘Nature Sight of the Week’ is the arrival of Black-footed Albatrosses to Laysan to begin their breeding season. These birds have been summering in the far north Pacific Ocean from Japan up to the Bering Sea and over to the North American coast, where they have been feeding on flying-fish, squid, and crustaceans. The first two were sighted on Sunday October 21 and more are arriving each day. The island will host up to 25,000 pairs, second only to Midway, which harbors the largest breeding colony of this species in the world. They will do an elaborate courtship dance that includes a simultaneous series of postures and calls by the male and female featuring moves such as a bow with wings extended, a ‘Sky Call’ performed on tip-toe, and ‘Head Up Clacker,’ in which the bill is rapidly clapped together.

Along with the 28 Black-footed Albatrosses, there is one Laysan Albatross on the lake edge and one Short-tailed Albatross in the North Desert. There are at least six Northern Pintails on the lake. Three juvenile Red Phalarope were seen swimming and foraging in the lake, and a Dunlin was also sighted. We continue to see Sharp-tailed Sandpipers (40+), a few Pectoral Sandpipers, and two Bar-tailed Godwits. The expected Ruddy Turnstones, Wandering Tattlers, and Pacific Golden Plovers are all along the lake edges.

[1] Editor’s note: see the blog posts below from Robby and Cameron Rutt describing their September 2011- March 2012 monitoring work on Laysan.