Lined forest falcon
{{Short description|Species of bird}}
{{Use American English|date=February 2023}}
{{speciesbox
| name = Lined forest falcon
| image = Lined Forest Falcon.jpg
| image_caption = Immature bird with brown iris and yellow face
| status = LC
| status_system = IUCN3.1
| genus = Micrastur
| species = gilvicollis
| authority = (Vieillot, 1817)
| synonyms =
| range_map = Micrastur gilvicollis map.svg
}}
The lined forest falcon (Micrastur gilvicollis) is a species of bird of prey in subfamily Herpetotherinae of family Falconidae, the falcons and caracaras. It is found in Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname, and Venezuela.{{cite web |url=https://www.worldbirdnames.org/new/bow/falcons/ |title=Seriemas, falcons |website=IOC World Bird List |version =v 13.1 |editor-last1=Gill |editor-first1= F. |editor-last2=Donsker|editor-first2=D.|editor-last3=Rasmussen |editor-first3=P. |date=January 2023 |access-date=February 11, 2023 }}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. 30 January 2023. Species Lists of Birds for South American Countries and Territories. https://www.museum.lsu.edu/~Remsen/SACCCountryLists.htm retrieved January 30, 2023
Taxonomy and systematics
Until 1972 what is now the lined forest falcon was considered a subspecies of the barred forest falcon (M. ruficollis); the treatment as a full species was confirmed in 2019.{{cite journal |last=Schwartz |first=P. |date=1972 |title=Micrastur gilvicollis, a valid species sympatric with M. ruficollis in Amazonia |journal=Condor |url=https://sora.unm.edu/sites/default/files/journals/condor/v074n04/p0399-p0415.pdf |volume=74 |issue=4 |pages=399–415 |doi=10.2307/1365892 |jstor=1365892 |access-date=February 11, 2023 }}{{cite journal |last1=Dos Santos Soares |first1=L.M. |last2=Bates |first2=J. |last3=Carneiro |first3=L.S. |last4=Dantas Santos |first4=M.P. |last5=Aleixo |first5=A. |date=2019 |title=Molecular systematics, biogeography and taxonomy of forest-falcons in the Micrastur ruficollis species complex (Aves: Falconidae) |journal=J. Avian Biol.|pages=e01943 }} (In the mid-20th century some previous authors had treated it as a species.) What is now the cryptic forest falcon (M. mintoni) was a population of the lined forest falcon until 2002 when vocal studies and specimen analyses determined it was a separate species.{{cite journal |last=Whittaker |first=A. |date=2002 |title=A new species of forest-falcon (Falconidae: Micrastur) from southeastern Amazonia and the Atlantic rainforests of Brazil |journal=Wilson Bulletin |volume=114 |issue=4 |pages=421–445 |doi=10.1676/0043-5643(2002)114[0421:ANSOFF]2.0.CO;2 |s2cid=55356779 |url=https://www.biodiversitylibrary.org/part/210405 }} The plumbeous forest falcon (M. plumbeus) has sometimes been considered a subspecies of the lined forest falcon.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
The lined forest falcon is monotypic.
Description
The lined forest falcon is {{convert|33|to|38|cm|in|abbr=on}} long and weighs {{convert|170|to|262|g|oz|abbr=on}}. It has pale gray upperparts. Its white underparts have highly variable gray barring, from light gray only on the breast to heavy bars on the entire underparts. Its tail is dark gray with a white tip and two narrow white bars. Its iris is white surrounded by bare reddish orange skin and its legs and feet are yellow.Bierregaard, R. O., P. F. D. Boesman, and J. S. Marks (2020). Lined Forest-Falcon (Micrastur gilvicollis), 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.liffal1.01 retrieved February 11, 2023
Distribution and habitat
The lined forest falcon is found in the Amazon Basin from eastern Colombia, eastern Ecuador, eastern Peru, and northern Bolivia east through Venezuela, the Guianas, and northern Brazil to the Atlantic coast. It mostly inhabits the interior of intact tropical primary forest, though it occurs in lower density in secondary forest and forest edges. In Colombia and Ecuador it prefers terra firme forest. In elevation it ranges from near sea level to {{convert|1600|m|ft|abbr=on}}.
Behavior
=Movement=
=Feeding=
The lined forest falcon hunts mostly in the forest understorey. Its diet has not been described in detail but is known to include lizards, large insects, birds, snakes, and small mammals. It sometimes follows army ant swarms.
=Breeding=
Essentially nothing is known about the lined forest falcon's breeding biology. It is probably similar to that of the barred forest falcon, which see here.
{{birdsong|url=https://xeno-canto.org/species/Micrastur-gilvicollis |species=lined forest falcon}}
=Vocalization=
The lined forest falcon's most common vocalization is a series of "nasal "cow-káh", "cow káw-káw" or "cow káw-káw-káw""notes. It typically calls before dawn and during wet weather.{{Cite journal|last1=Klein|first1=Bert C.|last2=Bierregaard|first2=Richard O.|date=May 1988|title=Movement and Calling Behavior of the Lined Forest-Falcon (Micrastur gilvicollis) in the Brazilian Amazon|journal=Condor|volume=90|issue=2|pages=497–499|doi=10.2307/1368582|jstor=1368582|issn=1938-5129}}
Status
The IUCN has assessed the lined forest falcon as being of Least Concern. It has a large range, but its population size is not known and is believed to be decreasing. No immediate threats have been identified. It is thought to be "the most abundant diurnal raptor over much of lowland forest of Amazonia, where it attains very high densities".