The Wikipedia article of the day for August 11, 2017 is Elfin woods warbler.
The elfin woods warbler (Setophaga angelae) is an uncommon bird species endemic to Puerto Rico. Discovered in 1968, it is the most recently described species of the New World warblers. The name angelae is a tribute to Angela Kepler, one of its discoverers. Characteristic of Antillean warblers (S. adelaidae, S. delicata, S. plumbea and S. pharetra), the species features a long bill and short, round wings (averaging 53.8 mm or 2.12 in). An insectivore, it feeds by gleaning small insects off leaves. El Yunque National Forest, where it was first captured, was initially believed to be its only habitat, but its largest population has been found in the Maricao State Forest. Due to its small numbers and restricted habitats, conservation efforts were begun in 1982 to protect this species. It is not in immediate danger as it lives mainly in protected forest, but potential threats include habitat reduction, natural disasters, and introduced species such as rats and small Asian mongooses.