Scott Shaffer, monitoring Midway Atoll. Every summer, the beaches of the Northwest Hawaiian Islands become filled with eager beavers. Well, actually not beavers, but albatrosses. Why call them eager beavers? Because they are young of the year or fledglings that are eager to leave the beaches and fly gracefully over the ocean swells like their parents. Starting in late June, black-footed and Laysan albatrosses test their wings on the light breezes that blow across these relatively flat islands. When the moment is right, these birds run out along the beach or into the water. If they are lucky, they might fly a few yards or more. After several attempts, they get it right and the wind carries them aloft. They are on their way.
Imagine climbing into a boat and sailing away from shore for the next five years. Now picture doing this without any prior guidance, without anyone to assist you, and not knowing where you should go. Which direction do you travel and how do you maneuver your boat? Eventually you become hungry. How and where do you search for food and what is it supposed to look like? What do you do when the weather turns bad? Daunting as this scenario may seem to a naïve sailor, every year fledgling albatrosses depart their nesting sites to explore the open oceans without any parental guidance or prior experience at sea.
Albatross chicks are generally close to adult body size and development upon fledging, however, they lack any substantial flying experience or knowledge of the ocean environment prior to departing the breeding colony. When fledging occurs, they head out to sea alone and unaided. Hence, they must develop and refine their skills at flying, as well as their ability to successfully search for and capture food, on their own. Although specific search images of prey may be evolutionarily “hardwired” into the brain, it is unclear whether fledglings know where or how to find food, how to navigate in a pelagic environment, or how temporal cues like season, lunar cycles, currents, tides, or sea state may affect prey availability. Locating ephemeral features that are associated with biological productivity, such as oceanic fronts, eddies, and upwelling centers, may also create challenges for naïve animals. Thus, it is not surprising that mortality rates of albatrosses are generally highest during the first few years of life at sea. Equally challenging for naïve animals on their first trip to sea is the need to recognize predators to avoid becoming prey or suffering injury.
To unravel some these mysteries, we are studying the first flights of fledgling black-footed and Laysan albatrosses to examine their behavior and where they fly from Midway Atoll, National Wildlife Refuge (28 N, 177 W) in the Northwest Hawaiian Islands. We are using small satellite transmitters to track the daily movements of the albatrosses during their maiden voyages to sea. Although we cannot predict how long each bird will be tracked, we hope to track the progress of the 9 fledglings for more than 6 months. Check back for updates on this blog or the TOPP website for more information. From Long Marine Laboratories, UC Santa Cruz.