New World Warblers

New World warblers, or wood-warblers, belong to the Parulidae family—a vibrant collection of small birds found solely in the New World and not closely related to the warblers of the Old World or Australia. Many of these birds live in trees, though some, such as the ovenbird and waterthrushes, are ground dwellers. These predominantly insectivorous birds likely originated in northern Central America, where the greatest diversity exists. They are known to migrate north during warmer periods, returning to their ancestral homes in the winter. Their family name, Parulidae, has evolved from Linnaeus's initial classification in the 18th century. Taxonomical changes and extensive molecular studies led to a reclassification of this family in 2010, resulting in the creation of monotypic genera and reshuffling of several species. Major genera like Myioborus and Basileuterus have a significant presence in South America, with the large Setophaga genus embracing species formerly placed in other groups due to priority rules in zoological nomenclature. The updated taxonomy of these warblers features 117 species distributed among 18 genera, each with their own unique characteristics. These warblers vary in size, with the smallest being Lucy's warbler and the largest surpassing 15 cm and 21 g. Migratory warblers generally lay more eggs to compensate for the risks of their journey, unlike their tropical counterparts, which tend to lay fewer eggs and provide more intensive care. Sexual dimorphism is prominent in species that need to establish territory and attract mates annually, especially in Setophaga, while it's less common in species that are sedentary and pair for life. However, dimorphism does vary, and some tropical species exhibit this trait as well. Recent studies have reclassified some former Parulidae members into their own families, such as the Peucedramidae for the olive warbler and the Icteriidae for the yellow-breasted chat, indicating the dynamic nature of warbler classification.