"preliminary DNA-DNA hybridization comparisons ... indicate that this species is either a relative of the Old World Eurylaimidae or a sister group of all other Tyrannida, as suggested by earlier biochemical studies .... In any event, it is not a close relative of manakins or any other recent tyrannoid."[4]
More recent research suggests that it is not a New World suboscine at all, but an Old World suboscine. In 2004, it was shown that the sapayoa is an outlier to the New World suboscines.[5] In an earlier analysis based on nDNAmyoglobinintron 2 and GAPDH intron 11 sequence data, the authors found the sapayoa
"as a deep branch in the group of broadbills and pittas of the Old World tropics."[6]
Accordingly, the sapayoa would be the last surviving New World species of a lineage that evolved in Australia-New Guinea when Gondwana was in the process of splitting apart. The sapayoa's ancestors are hypothesized to have reached South America via the Western Antarctica Peninsula.
All the systems agree that the sapayoa is monotypic.
Description
The sapayoa is 13.5 to 15 cm (5.3 to 5.9 in) long and weighs about 21 g (0.74 oz). Its head and upperparts are olive with a dusky tinge to the wings and tail. It throat and belly are a yellower olive. Its bill is wide and black with rictal bristles around it. Its iris is dull reddish brown and its legs are gray. Males have a yellow stripe on the crown.[11][12]
Distribution and habitat
The sapayoa is found from the Panama Canal Zone south through western Colombia into extreme northwestern Ecuador. It inhabits humid forest from the understory to the mid-level, and often occurs in ravines and near watercourses. In elevation it ranges as high as 1,200 m (3,900 ft) in Colombia but only to 500 m (1,600 ft) in Ecuador.[11][13][12]
Behavior
Movement
The sapayoa is assumed to be a year-round resident in its range.[11]
Feeding
The sapayoa typically feeds by perching for long periods between sallies to catch insects on the wing or from foliage. It also feeds on small fruits. It often joins mixed-species feeding flocks.[11][13][12]
Breeding
The sapayoa's breeding season includes at least March to September in Panama and February to April in Colombia. Its pear-shaped nest is made from long strips of bark and other fibers, some of which dangle beneath the structure, and has a side entrance near its bottom. It is suspended from a branch, often above a stream. Two nests each held two nestlings. Both parents fed the brood at one. At the other the female brooded them and an adult male and two immature males attended her and the brood.[11][14][15]
The sapayoa's vocalizations are not well known.[11] One is "a soft trill" and another is "a slightly louder 'chipp, ch-ch-ch' ".[12]
Status
The IUCN has assessed the sapayoa as being of Least Concern, though its population size is not known and is believed to be decreasing. No immediate threats have been identified.[1] It is "[a]pparently rare to uncommon, and possibly rather local in distribution."[11]
^Sibley, Charles Gald & Monroe, Burt L. Jr. (1990). Distribution and taxonomy of the birds of the world: A Study in Molecular Evolution. Yale University Press, New Haven, CT. ISBN0-300-04969-2
^Chesser, R. T., S. M. Billerman, K. J. Burns, C. Cicero, J. L. Dunn, B. E. Hernández-Baños, R. A. Jiménez, A. W. Kratter, N. A. Mason, P. C. Rasmussen, J. V. Remsen, Jr., D. F. Stotz, and K. Winker. 2022. Check-list of North American Birds (online). American Ornithological Society. https://checklist.americanornithology.org/taxa
^Remsen, J. V., Jr., J. I. Areta, E. Bonaccorso, S. Claramunt, A. Jaramillo, D. F. Lane, J. F. Pacheco, M. B. Robbins, F. G. Stiles, and K. J. Zimmer. Version 30 January 2023. A classification of the bird species of South America. American Ornithological Society. https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm retrieved January 30, 2023
^ abClements, J. F., T. S. Schulenberg, M. J. Iliff, T. A. Fredericks, J. A. Gerbracht, D. Lepage, S. M. Billerman, B. L. Sullivan, and C. L. Wood. 2022. The eBird/Clements checklist of birds of the world: v2022. Downloaded from https://www.birds.cornell.edu/clementschecklist/download/ retrieved November 10, 2022
^ abcdefgSnow, D. (2020). Sapayoa (Sapayoa aenigma), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.sapayo1.01 retrieved April 26, 2023
^ abcdRidgely, Robert S.; Greenfield, Paul J. (2001). The Birds of Ecuador: Field Guide. Vol. II. Ithaca: Cornell University Press. pp. 563-564 plate 78. ISBN978-0-8014-8721-7.
^ abMcMullan, Miles; Donegan, Thomas M.; Quevedo, Alonso (2010). Field Guide to the Birds of Colombia. Bogotá: Fundación ProAves. p. 115. ISBN978-0-9827615-0-2.
Irestedt, M.; Ohlson, J.I.; Zuccon, Dario; Källersjö, M. & Ericson, Per G.P. (2006). Nuclear DNA from old collections of avian study skins reveals the evolutionary history of the Old World suboscines (Aves: Passeriformes). Zool. Scripta 35(6): 567–580. doi:10.1111/j.1463-6409.2006.00249.xPDF fulltext