Mangrove Cuckoo is widespread, ranging from southern Florida and northern Mexico south through the West Indies and Central America to the northern tip of South America, and occurs in a variety of habitats, yet its natural history remains almost a complete mystery. Even in reasonably accessible habitats, it is difficult to observe. The vocalizations of Mangrove Cuckoo are distinctive and can be loud, but are given relatively infrequently. Although willing to approach edges and cross openings, Mangrove Cuckoos tend to forage within the tree canopy and will remain still for long periods as they peer about searching for prey. When they do move, Mangrove Cuckoos often walk silently from branch to branch rather than take flight, further reducing the chance that they are detected.
Basic information on most aspects of breeding ecology, including habitat selection, phenology, and parental care are undescribed. Estimates of key demographic parameters, such as clutch size, nest success, and annual survival, are lacking. Much uncertainty remains regarding molt patterns. Contemporary reviews have looked doubtfully on historic descriptions of geographic patterns of variation in morphology and plumage color, once the basis for splitting Mangrove Cuckoo into 14 distinct subspecies, although a definitive answer awaits a rigorous re-examination of existing museum specimens. Seasonal movements also are undescribed, with some populations thought to be migratory or partially migratory, and others considered resident; in any case, no evidence exists that would allow for the resolution of this question.
Mangrove Cuckoos are classified as a species of Least Concern by the IUCN, and its wide range and apparent use of a variety of habitats, including disturbed and second-growth forest, would lend credence to this designation. Given that its distribution has been described only in the roughest sense, however, and given that no range-wide estimates of abundance exist, it may be prudent to consider the conservation status of Mangrove Cuckoos as, like nearly everything else about it, "unknown at present."