Early bird specialists ascribed the distinct physical differences that they observed between individuals of the broad-billed tody to simple variations between males and females of the same species. They corrected their error in the early 1900s, with the exciting discovery of the existence of two distinct species. The new species was the narrow-billed tody, which along with the broad-billed tody, are members of a peculiar bird family of the Greater Antilles, the todids or todies. Only Hispaniola has two species –or perhaps even three, since a genetic study suggested that differences between the narrow-billed tody populations residing north and south of the Neiba Valley/Cul-de-Sac Plain, suffice to separate it into two distinct species. As with other sister species of Hispaniola, this surprising diversity of todies, can be attributed to the island’s wide range of elevations, as well as its peculiar geological origin.
First, the high mountains of the island (reaching over 3,000 meters) and complex topography created a range of different and sometimes isolated habitats in which different populations evolved and adapted. Second, the island that we know today as Hispaniola resulted from the union of two major paleoislands roughly 10 million years ago, joining where today we find the Neiba Valley/Cul de Sac Plain, an ancient marine channel that connected the bays of Neiba and Port-au-Prince. Apparently, common ancestors of these birds adapted and evolved separately on each of the paleo-islands, only to be reunited when the landmasses came together long ago.
Although very similar to the broad-billed tody, close observers can distinguish the narrow- billed tody by its slightly smaller size, its narrower, longer bill, its dusky blue eyes, and the black tip of its lower bill. Also, the narrow-billed tody’s plumage is generally brighter, its belly is whiter, its flanks are gray– in contrast to the broad-billed tody’s pink sides. Nevertheless, these two todies are most easily and reliably distinguished by voice. Honoring its Spanish name, “chicuí” the narrow-billed tody’s call note is a frequently repeated, 2-part chick-kweee, accented on the second syllable. Another distinction is the narrow-billed tody’s preference for higher altitudes, typically ranging from 900-2,400 meters, but extending up to 3,000 meters.
“Despite its camouflage, it is a fearless creature.” Anabelle Stockton de Dod
The narrow-billed tody does occur in pine forests and high altitude coffee plantations, but appears to favor humid forests with lush vegetation, bamboo vine and a thick cover of epiphytes of every kind, including mosses, lichens, orchids and Spanish moss. While not particularly shy, it can be even more difficult to see than the broad-billed tody, due to its small size and to the dense vegetation that it favors. A single leaf can hide it completely from view. Like its close relative, the narrow-billed tody is a major insect predator, although it forages even more actively. Like other todies, the narrow-billed tody makes its nests in ravines or earthen banks, excavating the soil with its bill and its feet. They are very attentive parents, with some of the highest chick-feeding rates recorded for any insectivorous bird species. This highlights the tody’s importance in controlling insect pests. It remains a relatively common bird within its range and in appropriate habitat, although its numbers are greatly reduced due to the loss of the humid mountain forests that it prefers.