27 Jan The Next Wave… Pihemanu Prepares to Welcome the Future
Midway Atoll National Wildlife Refuge (NWR), alternatively known as Pihemanu (the “loud din of birds”), has entered a relatively still time of the year—or as quiet as it can be on a tiny atoll packed with nearly 2 million seabirds. While the non-breeding albatross continue to whinny, whistle, moo, scream, and boogie all night long, the rest of the albatross have long since hunkered down, patiently incubating their one and precious egg. That single egg is precious indeed considering that albatross only lay one egg per year and will not re-lay if their egg becomes damaged, lost, or otherwise. That fact become all the more salient when one considers that albatross (like many of bird species within the Procellariiformes, an order of seabirds that also includes petrels, shearwaters, storm petrels, and diving petrels) are very long-lived species that also exhibit delayed sexual maturity—it can take 5 years from when they fledge before they start to breed! In fact, it is likely that it takes additional years of practice for these seabirds to breed successfully, learning over time the art (and importance) of building a warm and dry nest-cup, proper incubation techniques, and honing their skills at sea to find needed food resources for themselves as well as an ever-hungry chick back on the colony.
Although the initial commotion of the breeding season has given way to the present hushed period, one of quiet waiting, the surrounding environment has become increasingly wild. Winter has long since settled in and storms rage through the atoll, turning the once serene blue and turquoise lagoon waters into a choppy scene of white crests, the exposed reef disappearing into the low-hanging, gray clouds, heavy with rain. Days flow by, often beginning with torrential downpours early in the mornings, then giving way to blustery afternoons with precious few moments of calm in between. In those moments, when the sun does peek through, incubating albatross stand up, give their wings a quick stretch, and take several deep beats to relieve their stiffened muscles from resting in place for days on end. Albatrosses, like all Procellariiformes, have extended incubation periods which are tied to the relatively slow rate of embryonic and nestling growth. So how long does it take before the eggs hatch? All in all, albatross typically incubate for about 65 days! From just prior to Thanksgiving to this current moment, albatross have been incubating non-stop on Midway Atoll NWR. But, 65 days without a break would be impossible for one bird alone, so both albatross parents participate in incubation. Not too long after the initial egg-laying event, the male will relieve the female while she returns to sea to replenish herself after such a draining activity. This is usually the longest incubation stint, averaging a bit longer than 2 weeks in duration.
Now, as the incubation period starts to reach its end, there seems to be a feeling of excitement in the fields spreading like an invisible, electric pulse. A different sound is now part of the soundscape, subtle but noticeable. Incubating albatross have begun to recite gentle “eh eh” calls to their egg, seemingly calling to the chick within it, small words of encouragement, a welcome song to the world. In return, if you listen very carefully, you might hear a soft “peep!” from beneath incubating albatross. That is the sound of pipping, the start of shell breaking, emergence, and the next wave of albatross—the future. Pipping is the start of hatching when the aircell within the egg itself is penetrated by the chick’s bill (via a special pointy tip call the “egg tooth”); this is known as internal pipping. A few days later, this is followed by external pipping, when the shell is physically fractured by the chick to produce a small hole. This hole is the first peek into the world for this chick, its first breath of fresh air. Hatching can be an arduous effort and the increased oxygen flow that comes from the hole in the shell is critical to the chick successfully breaking free of its calcium-based chamber. After much struggling, which can sometimes take more than a day, the chick finally breaks free, the last bits of shell fall apart.
This week marks the start of hatching—only a couple of days ago did we find the first chick of the season! Since Black-footed Albatross lay their eggs, on average, anywhere from a couple of weeks to a few days earlier than their Laysan Albatross cousins, the first chicks of the season are Black-footed Albatross chicks! Curiously enough, these chicks feature an all-white bundle of downy feathers, quite a contrast to the burnt coffee timbre of their parents’ plumage. To all of the Ka’upu and Mōlī chicks to come… e komo mai! Welcome to the world!