The White-tipped Sicklebill, known scientifically as Eutoxeres aquila, is a hummingbird of remarkable design. Its most striking feature is the pronounced curvature of its bill, which arcs through a quarter circle, presenting a black maxilla and a contrasting yellow mandible. This species measures approximately 11.5 to 13.5 cm in length and tips the scales at a delicate 8.6 to 14.5 grams. Both male and female exhibit similar plumage, with adults donning green upperparts, a blackish throat and chest, and underparts adorned with green and white stripes. The tail is predominantly green, save for the outer feathers which are duskier and tipped with white. Juveniles can be distinguished by their scaly appearance.
When identifying the White-tipped Sicklebill, look for its unique bill shape and the white tips on the tail feathers. The bird's size and coloration are also indicative, with the green and white striped underparts being particularly distinctive.
This species is a denizen of the montane evergreen forest understory, where it flits about in the dappled light.
The White-tipped Sicklebill graces various countries with its presence, including Colombia, Costa Rica, Ecuador, Panama, Peru, and Venezuela. Its range is divided among three subspecies, each with its own geographical niche.
The White-tipped Sicklebill is not one to defend a territory; rather, it is a "trap-line" feeder, moving from flower to flower along a regular route. It clings to flowers while feeding, a behavior facilitated by its uniquely shaped bill, which is perfectly adapted to the contours of certain blooms, particularly those of the Centropogon and Heliconia genera. In addition to nectar, these birds also glean insects from spiderwebs and vegetation.
The vocal repertoire of the White-tipped Sicklebill includes a complex series of squeaks and high-pitched 'tseep' notes, with some variation noted across its range. Its call is described as a high, sharp, and piercing 'tsitting'.
Breeding behaviors include a U-shaped flight display by males at leks, indicative of their polygynous nature. The breeding season varies by location, and the species may breed twice annually. Females construct a hanging cup nest from various natural materials, often suspended from Heliconia leaves or even man-made structures. Clutches typically consist of two eggs.
The White-tipped Sicklebill could potentially be confused with its congener, the Buff-tailed Sicklebill (E. condamini), but the white tips on the tail feathers are a distinguishing feature.
Nectar forms the cornerstone of the White-tipped Sicklebill's diet, with its bill shape being a specialized adaptation for accessing the nectar of certain flowers. Insects supplement this diet, often captured from spiderwebs or directly off plant surfaces.
The IUCN has classified the White-tipped Sicklebill as Least Concern. While the exact population numbers and trends are not well-documented, the species could face threats from habitat fragmentation due to its reliance on forested environments and specific flowering plants for sustenance.