A Smooth Hand Off

August 20 – September 2
Michelle Wilcox

Figure 1. A Millerbird receives a radio transmitter. Photo: Ryan Hagerty/US Fish and Wildlife Service.

Last week Laysan Island bid farewell to John Vetter, Millerbird Monitor for spring and summer 2012. He left a trove of information from his detailed observations of Millerbird behavior and reproduction that we will continue to build upon. The island welcomed not only 26 more translocated Nihoa Millerbirds, but me, Michelle Wilcox, the newest Millerbird Monitor for fall and winter, along with Robby Kohley who is here to help with translocation, post-translocation monitoring, and to train me on all things Millerbird-related. Robby first came to Laysan in September 2011 with Phase 1 of the Millerbird translocation project and monitored Millerbirds along with Cameron Rutt for the first six months after Millerbirds were released. I am very grateful for being able to tap into his wealth of knowledge and his history with this species.

We attached temporary radio transmitters to each of the newly released birds that will emit signals for 21-35 days and allow us to track the birds’ locations. Twenty-five of the birds have been re-sighted and are doing well and displaying interesting dispersal patterns. Some are moving to the edges of the current ‘core area’ of Millerbird activity in the northern part of the island, while others are carving out parcels in between the territories of males that have been here for a year. Some of the new birds are even exhibiting signs of early courtship behavior.  The twenty-sixth bird is a quiet female. We believe her transmitter is not working which means she will be much harder to find, but we hold high hopes of finding her during interactions she may have with other Millerbirds.

We have also been monitoring the six Millerbird nests that John had found in his last month on the island.  Two of the nests have produced a total of three fledglings, and four nests are in the nestling stage. This brings the grand total of chicks fledged thus far in 2012 to 20! This is fantastic news for the species and a huge success for the translocation project in general. There is still plenty of unoccupied habitat and there are plenty of insect food resources for all of these new birds to thrive and expand their population.

Figure 2. Michelle Wilcox tracking Millerbirds. While Millerbirds eat flies, they clearly don’t eat enough! Photo: Chris Farmer/American Bird Conservancy

The island is an orchestra of bird song all through the night with Wedge-tailed Shearwaters and Christmas Shearwaters doing their mating calls and Brown Noddy chicks begging for food. These three species are still producing chicks all over the island, whereas Bonin Petrels are just starting to arrive in small numbers. We see juvenile White Terns and Great Frigatebirds scattered around the island as well as a few Masked Boobies and Red-footed Boobies still waiting to be fed by adults. For all of these species Laysan Island is a rare breeding refuge free from mammalian predators, and for this reason tens of thousands of seabirds come here to nest.

Instead of Resight of the Week, I want to start a new series called Nature Sighting of the Week. This is going to be hard since I am new here and everything is wondrous and fascinating to me, but if I had to pick one from the past week, I would choose the Christmas Wrasse that came to visit me in the shallows of the camp beach on my first day on Laysan. This 8 inch fish is dressed in the most vivid blues, greens, and yellows that he looks like his colors have been enhanced for cinematic effect. It is as if he was saying, “Welcome to Laysan. If you are observant and patient enough we will put on quite a show for you!”

Beginnings and Endings

August 6 – August 19
John Vetter

An action-packed two weeks was a great way to finish up my time on Laysan.  The arrival of the translocation crew from Nihoa with 26 more Millerbirds went very smoothly and was a great success overall.  This also marks the return of Robby Kohley to Laysan and the arrival of Michelle Wilcox, who will take over monitoring and tracking responsibilities.  But, before I left, I was able to document the continued success of the current population of Millerbirds on Laysan, as three new nests (and a probable fourth) were found during the past two weeks, bringing the total to probably six active nests Let’s hope that the new arrivals take to the island as well as the previous cohort.

The other island inhabitants continue to do well, as large numbers of Sooty and Gray-backed Tern fledglings are moving around the island.  Also, the first fledgling Brown Noddies have been noted.  Large numbers of cute bundles of puff in the form of baby Wedge-tailed Shearwaters are showing up in many areas of the island.  This period also marked the first indications of fall migration, as up to seven Sanderlings were found foraging around the interior lake.  A number of the Pacific Golden-plovers and Ruddy Turnstones also appear to be fresh arrivals from the northern breeding grounds. 

This last blog post from me also has me looking back on my time on the island, and some of the key life lessons that I have learned.  Such as:

• A rainbow moving away from you is beautiful; one moving toward you means you are going to get wet.
• If a double rainbow is coming at you, you are going to get twice as wet.*
• A clean pillow is a luxury often overlooked.
• When the flies are really bad, always face the wind when drinking from your Nalgene.
• Some smells linger for a long, long time.
• Finally, as I have learned from the Brown Noddies, sometimes you just need to stop and stare at your feet to make sure that they are still on the ground.

*Not intended to be taken as scientific fact.

At It Again

July 9 – July 22
John Vetter

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 13^th 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.

Beginnings and Endings

July 23 – August 5
John Vetter

 As my time on Laysan winds down to its last couple of weeks, a new cycle of breeding is beginning for the Millerbirds—their third since they were brought to Laysan from Nihoa just eleven months ago.  Two active nests are in incubation, and a few more pairs might be looking to breed again as well.  For me, this is somewhat bittersweet, as I will not be around to see many of these nests fledge, but, it is a great feeling knowing that the birds have already had a very successful season and seem intent on reclaiming the island as their home as quickly as possible.  I hope that by the next time I write, they will be joined by another eager group of birds from the second translocation effort from Nihoa, which will be getting underway very soon.     

 Our ‘Resight of the Week’ feature seems to be increasingly awarded to female Millerbirds, and this week is no different, with female Bk/S, B/O (Black over Silver bands on left leg; Blue over Orange on right leg) deciding to show up right in the middle of her territory on a few different occasions.  Where she has been for the previous 50 days, only she knows.  I also have to mention the previous recipient, O/W, O/S, since she was once again observed (rare times indeed), and this time she was making her way to her nest to relieve the male of incubation duties. 

 Most of the Albatrosses have left, and the island has begun to feel a little empty.  As some of the most numerous, largest, and most charismatic birds on the island, they tend to dominate the attention while they are here.  Luckily, we still have the Brown Noddies.  Also one of the more numerous species on the island, they show little fear of anything, even attacking the much larger and fearsome Great Frigatebirds.  Now, we have little Brown Noddy chicks roaming around camp, investigating every little nook and cranny.  With quite a bit of charisma themselves, these little guys are a pleasure to watch grow, as they perfect the “Noddy foot stare:” gazing straight down at their feet as if to make sure they’re both still there.  Another highlight of the period has been finding the first Wedge-tailed Shearwater chicks of the season, though, undoubtedly many, many more are to come.   

 On the shorebird front, we still have the main four species: Pacific Golden Plover, Ruddy Turnstone, Wandering Tattler, and Bristle-thighed Curlew, with individuals over-summering; no new migrants have arrived as of yet.  We might still be a month or so away from the influx of rare and noteworthy shorebird sightings. 

Fledgling Independence Day

Millerbird with spider.

June 25 – July 8
John Vetter

This two-week period was a study in contrasts for the Millerbirds, and showed how frustrating and rewarding working with this species really can be. The first week was hot and dry and many birds had begun post-breeding molt. Thus, birds were very quiet (two songs all week!) and I managed to find only four of them the entire week, often leaving me wondering if there really were Millerbirds on this island. However, cool, wet conditions prevailed the following week and suddenly they appeared everywhere, once again singing and moving about extensively in the foliage. While adults continued feeding their chicks early in the period (Photo 1), by the end of the two weeks many of the young fledglings had begun to strike out on their own. So keeping track of these little ones will become more difficult. Luckily for me, curiosity is a defining characteristic of hatch-year Millerbirds, and I do not have to find them as much as realize that they have already found me and are peering intently at me from a few feet away.

The Resight of the Week this week goes to Bk/Y, G/S. This small female is one of the more difficult Millerbirds to find due to her territory in very thick, dense vegetation. After last resighting her on May 19th, I found her again on July 6th quietly preening in the vegetation. Both her tail and her wings were fresh and still re-growing after molt.

The albatross colonies are beginning to thin, as many of the chicks took full advantage of the recent windy conditions to hone their flight skills and head out to sea. Many are still in the learning curve, however, and crash landings are common. One definitely needs to keep one’s eyes and ears alert when walking around the interior lake, where many of the Laysan Albatross chicks are learning. More than once I have had to duck out of the way of an out-of-control fledgling. Among the other birds, the Brown Noddies have begun hatching. Seemingly every nest on the island hatched during a two-day period last week. More small Laysan Duck chicks have begun appearing as well, while many of the early chicks are now out on their own. As with young Millerbirds, these fledgling ducks are often found in groups and are extremely curious about the people working on the island.

There are still no unusual migrants or vagrants around the island, but the Bristle-thighed Curlews and Ruddy Turnstones are keeping many of the seabirds on their toes. Both of these species are known egg predators, especially the curlew. Anytime one of these birds flies around the island, it is accompanied by a strong contingent of vigilant seabirds, usually Sooty Terns. The Blue-gray Noddy continues its residence on the island, being found regularly in the heliotrope trees along the beach.

Quiet Mice and Running Rocks

June 11 – June 24
John Vetter

Fig. 1. A male Brewster’s Booby and his chick. This subspecies of Brown Booby, distinguished by the male’s pale head and bill, is uncommon in the Hawaiian Islands. Photo: J. Vetter

Summer is in full force out here on Laysan, which unfortunately means a slowing of the Millerbird breeding season. Singing has dropped dramatically the last two weeks, and our last active nest fledged two more chicks, bringing the season’s total to 17 chicks fledged from 11 nests. Since most of the pairs are currently feeding fledglings, it may be another two to three weeks before we can officially put this season in the books, but at least a few pairs seem content with the young they have produced and have hung it up. A few of these have shown signs of post-breeding molt, with the birds losing their entire tails at once. This just reinforces the notion and appearance of quiet mice running through the vegetation.

One of the more important questions for us now is the dispersal and survival of the fledglings and juveniles. To that end, and for a clearer picture of the overall Millerbird population as we move forward, we have started banding these young birds as they leave their natal territories for parts unknown on the island. The Resight of the Week for this period goes to B/S, O/R, a female seen late last week after having eluded detection for over a month, despite feeding a young fledgling for most of this time.

Newly fledged Black-footed and Laysan Albatrosses have moved beyond the short air-time achieved from hopping into a strong wind to actually taking off from a running start, both from land and from the lake in the middle of the island, and flying around the island. With no down present and good control over their flight capabilities, many young Black-footed Albatrosses require a double-take to differentiate them from adults. In addition to these young birds fledging, many other young chicks have been hatching during the last two weeks. In particular, three species of tern now have chicks. Sooty Terns nest in vast colonies of hundreds of thousands of birds that ring the interior bunchgrass areas of the island, while Gray-backed Terns nest in smaller colonies of up to100 birds scattered throughout the low vegetation of the island. Both species have semi-precocial chicks that do their best to emulate a rock before darting out and running to another spot, where they then do their best to look like a different rock. The third species with new chicks are the bush- and tree-nesting Black Noddies, which build more traditional nests. These chicks (which would give any other chick on the island a run for the cutest) stay put in the well-constructed platform of leaves and branches.

No unusual migrants or vagrants showed up this period, which is to be expected in the summertime. We do, however, still have a couple of the brewsteri subspecies of Brown Booby nesting in the south of the island. One male has now been joined by a chick (Photo 1), while the other continues to incubate eggs.

Flight Training

May 28 – June 10
John Vetter

Fig. 1. A fledgling millerbird. This is one of three siblings; the largest brood of millerbirds ever documented to fledge.

We had yet another exciting two weeks out here with the Millerbirds. Foremost among that excitement was the fledging of three more nests, including one pair that successfully fledged three chicks, quite a rarity for the Millerbirds.  Perhaps just as exciting is seeing many of the chicks that fledged early now independent and moving throughout the naupaka (Scaevola taccada) foraging on their own.  It remains to be seen if the Millerbirds will continue to breed into the summer, but observations of the Laysan Finches continuing their nest-building activities bode well for the Millerbirds.

Resights were a struggle this reporting period. Females, in particular, are very difficult to find when one does not have a nest to help pinpoint them in the jungle of naupaka and beach morning glory (Ipomoea pes-caprae) where they reside.  So, the “Resight of the Week” will go to the three young fledglings (one of the brood appears in Fig. 1).  They hung on in the nest a little longer than many of the other chicks, but I like to think that they just wanted to wait to give me a very welcome birthday gift.

Elsewhere on the island, we had some strong rain showers this past weekend, which were a welcome relief from the heat, and, more importantly, from the burgeoning fly population. The winds that accompanied the rain were also a welcome gift to the young albatrosses.  With their flight feathers mostly grown, they have started the first agonizing moments of flight training.  Wings spread and hopping into the wind, a few have managed to leave the ground, albeit for short, very unsteady bursts.  While masters of the wind as adults, it evidently takes a bit of practice to fully grasp the concepts of aerodynamics.

The summer population of shorebirds seems to be set and we have nearly the full complement of breeding birds on the island at the moment.  While most of the birds are in the beginning or middle of their breeding season, both the Tristam’s Storm-Petrel and Bonin Petrel are finishing up.  While fewer and fewer adults return each night, many of the chicks are out and about on the surface during the evenings exploring life outside of the burrow before they take off into the wide Pacific.