The Laysan finch ( Telespiza cantans) is a small bird found exclusively on Laysan Island, a remote atoll within the Northwestern Hawaiian Islands. This species of Hawaiian honeycreeper holds particular significance as an island endemic, representing a specialized lineage adapted to its isolated environment.
Physical Characteristics and Habitat
The Laysan finch measures 15 to 18 centimeters (6 to 7 inches) in length. Males exhibit vibrant yellow plumage on their head, throat, and breast, with a whitish belly and a gray neck collar. Females, by contrast, display duller coloration with more muted yellow tones and brown streaking, particularly on their back and wings. Both sexes possess a robust, conical, bluish-gray bill, well-suited for their diet.
This species is restricted to the low-elevation, flat expanse of Laysan Island, an atoll spanning approximately 411 hectares (1,016 acres). The finches inhabit all vegetated areas, foraging among grasses, herbs, and prostrate vines. They primarily construct their nests within tussocks of the bunchgrass Eragrostis variabilis.
Diet and Foraging Behavior
The Laysan finch is an omnivorous Hawaiian honeycreeper with a diverse diet reflecting its adaptability to a resource-limited island environment. Their primary food sources include seeds, fruits, leaves, flowers, stems, seedlings, and roots from various plants. They are known to consume the seeds of Eragrostis variabilis and flowers of Tribulus (Nohu).
Beyond plant matter, the finches also feed on invertebrates, such as insects and their larvae. A notable aspect of their foraging behavior is the consumption of seabird eggs. While they cannot break the eggs of larger seabirds like albatrosses, they will scavenge from them and actively take eggs from smaller species such as white terns and the Laysan duck. They also forage on carrion, including dead seabirds and Hawaiian monk seals, to access emerging fly larvae or other invertebrates.
Conservation Status and Recovery Efforts
The Laysan finch is recognized as “Vulnerable” by the IUCN Red List and is listed as “Endangered” by both the U.S. federal and Hawaii state governments. Historically, the species faced a severe population bottleneck in 1923, when its numbers dwindled to fewer than 100 individuals due to the devastating impact of introduced European rabbits that denuded the island’s vegetation. Although the rabbits were removed, this event caused a reduction in the finch’s genetic diversity.
Ongoing threats to the Laysan finch include habitat degradation from invasive alien plants, such as Setaria verticillata and Verbesina encelioides, which can displace native vegetation and affect nesting success. The inherent vulnerability of small, isolated populations to demographic and environmental fluctuations, including severe storms and overwash events, also poses a continuous risk. Climate change and rising sea levels present a long-term concern for these low-lying island habitats.
Conservation measures have focused on habitat protection and species reintroductions. The entire range of the Laysan finch falls within the Hawaiian Islands National Wildlife Refuge. Since 1967, translocations have established populations on other islets, including Southeast Island and Grass Island at Pearl and Hermes Reef, to create backup populations and reduce the risk of extinction from a single catastrophic event. Efforts also include aggressive weed control, native plant restoration, and vigilance against the introduction of invasive mammals like rats, which have historically extirpated finch populations on other islands where they were introduced, such as Midway Atoll.