Cryptic forest falcon

{{speciesbox | image = Micrastur mintoni - Cryptic Forest Falcon; Parauapebas, Pará, Brazil.jpg | status = LC | status_system = IUCN3.1 | status_ref = <ref name="iucn status 12 November 2021">{{cite iucn |author=BirdLife International |date=2016 |title=''Micrastur mintoni'' |volume=2016 |article-number=e.T22733700A95062533 |doi=10.2305/IUCN.UK.2016-3.RLTS.T22733700A95062533.en |access-date=12 November 2021}}</ref> | genus = Micrastur | species = mintoni | authority = Whittaker, 2003 | synonyms = | range_map = Micrastur mintoni map.svg }}

The '''cryptic forest falcon''' ('''''Micrastur mintoni''''') is a species of bird of prey in the family Falconidae. It is found in the southeastern Amazon rainforest in Brazil and Bolivia. While uncommon in its Amazonian range, it remains widespread and is therefore rated as least concern by BirdLife International and IUCN. Unlike the lined forest falcon, with which it has long been confused in a cryptic species complex, adult cryptic forest falcons only have a single white tail-band (in addition to a narrow white tail-tip).

==Description== The cryptic forest falcon is a rarely spotted bird of prey.<ref name=":1">{{Citation|last1=Fjeldså|first1=Jon|title=Cryptic Forest-Falcon (Micrastur mintoni)|date=2020-03-04|work=Birds of the World|publisher=Cornell Lab of Ornithology|last2=Marks|first2=Jeffrey S.|last3=Sharpe|first3=Chris|editor1-first=Josep|editor1-last=Del Hoyo|editor2-first=Andrew|editor2-last=Elliott|editor3-first=Jordi|editor3-last=Sargatal|editor4-first=David|editor4-last=Christie|editor5-first=Eduardo|editor5-last=De Juana|doi=10.2173/bow.cryfof1.01|s2cid=243177434 }}</ref> When spotted, it is often confused for its congeners, the barred forest falcon, the lined forest falcon, and the plumbeous forest falcon.<ref name=":1" /><ref name=":0" /> While it differs slightly from its congeners in its physical characteristics, it is best recognized by its distinctive vocalizations.<ref name=":0" /> Its height is 30-35 centimeters, and its weight is 170-264 grams for females (171-238 grams for males).<ref name=":0" /> Its plumage is grey (often darker on head), with a blackish upper wing and rump.<ref name=":1" /> Its bare red facial skin and single broad white tail bar distinguish it from the barred forest falcon.<ref name=":1" /> Immature individuals have two narrower white tail bands.<ref name=":1" /> Sometimes, an additional tail band is present, and is covered by the bird's upper tail coverts.<ref name=":0" /> With a wing:tail ratio of 1.36, its short tail further distinguishes it from the lined forest falcon.<ref name=":1" /> Its chin, central throat, and underparts are white.<ref name=":0" /> Its breast is white, with fine dark grey bars (generally bolder in females).<ref name=":0" /><ref name=":1" /> These bars are more defined near the birds lower throat/upper breast.<ref name=":1" /> This barring is greatly reduced on immature individuals.<ref name=":1" /> It has a black beak, with an orange base, and greyish iris.<ref name=":1" /> Sometimes a diagonal line across its cheek is present in immature individuals.<ref name=":1" /> Its legs are orange, with blackish claws.<ref name=":1" />

=== Sexual dimorphism === ''M. mintoni'' is lightly sexually dimorphic, with females having a slightly higher weight range, and bolder ventral barring.

== Taxonomy == The cryptic forest falcon is a member of the family Falconidae, which includes falcons and caracaras. It is a member of the genus ''Micrastur'', which encompasses all forest-falcons. It is a monotypic species.<ref name=":1" /> Specimens were historically labeled as lined forest falcons until the cryptic forest falcon was recognized as a distinct species in 2002. While it closely resembles its congeners, it can be distinguished by its distinctive vocalizations, as well as slight morphological difference.<ref name=":0">{{Cite journal|last=WHITTAKER|first=ANDREW|title=A New Species of Forest-Falcon (Falconidae: Micrastur) from Southeastern Amazonia and the Atlantic Rainforests of Brazil|date=2002|journal=The Wilson Bulletin|volume=114|issue=4|pages=421–445|doi=10.1676/0043-5643(2002)114[0421:ansoff]2.0.co;2|s2cid=55356779 |issn=0043-5643}}</ref>

== Habitat and distribution ==

=== Habitat === The cryptic forest falcon primarily inhabits the lowland ''terra firme'' forests of South America, a habitat characterized by its tall trees and dense, diverse understory.<ref name=":1" /> It also frequents the Várzea forest, a seasonally flooded forest with a bamboo understory.<ref name=":1" /><ref name=":2">Simon, J. and Gustavo Rodrigues Magnago. "Rediscovery of the Cryptic Forest-Falcon Micrastur mintoni Whittaker, 2002 (Falconidae) in the Atlantic forest of southeastern Brazil." ''Revista Brasileira de Ornitologia - Brazilian Journal of Ornithology'' 21 (2014): 6.</ref> A population also exists in the Atlantic Rainforest of eastern South America.<ref name=":2" />

=== Distribution === This species has a wide distribution throughout South America, and is believed to occur over 19,300,000 km<sup>2</sup>.<ref name=":3">{{Cite web|last=International)|first=BirdLife International (BirdLife|date=2016-10-01|title=IUCN Red List of Threatened Species: Micrastur mintoni|url=https://www.iucnredlist.org/en|access-date=2020-10-14|website=IUCN Red List of Threatened Species}}</ref> There are two known populations of the cryptic forest falcon, the first of which is throughout southeastern Amazonia, from north-east Bolivia to Para, Brazil.<ref name=":1" /><ref name=":3" />

A disjunct population, thought to be potentially extinct until its rediscovery in 2012 exists in the Atlantic Rainforest of eastern South America. The status of this population is not currently known, and is likely critical.<ref name=":1" /><ref name=":2" />

== Behavior ==

=== Vocalizations === The cryptic forest falcon is most recognizable for its vocalizations, primarily its distinctive song. This song consists of a series of "uk uk uk uk" notes, at one note per second.<ref name=":1" /><ref name=":4">{{Cite web|title=Cryptic Forest-Falcon - eBird|url=https://ebird.org/species/cryfof1|access-date=2020-10-15|website=ebird.org|language=en}}</ref> This song usually lasts for 1-1.5 minutes.<ref name=":1" /> This song is used to alert others of its territory.<ref name=":1" /> In addition to its song, the forest-falcon has two calls. The first of which, is its cackling call.<ref name=":1" /> This call is a series of short "ca ca ca ca-ca-ca notes, with the last three notes closer together, and dropping in pitch throughout.<ref name=":1" /><ref name=":4" /> Its quacking call is least often heard, and consists of loud "uuk, qui, qua-qua" notes.<ref name=":1" /><ref name=":4" /> The cryptic forest falcon is typically heard at dawn.<ref name=":1" /> However occasionally it can be heard later in the morning during dry season.<ref name=":1" /> It is less often heard just before dusk.<ref name=":1" />

=== Diet and hunting strategy ===

==== Diet ==== The cryptic forest falcon is believed to be a generalist.<ref name=":1" /> It is known to prey on reptiles and invertebrates.<ref name=":1" /> It is also believed to prey on small birds, as one individual emerged to a recording of the rufous-necked puffbird.<ref name=":1" />

==== Hunting strategy ==== While little information is known about its hunting strategy, it is believed to be similar to that of its congeners; watching from low perches in the understory, emerging to seize prey.<ref name=":1" />

=== Breeding === Very little information is known about the cryptic forest falcon's breeding behavior. It is believed to nest in the wet season (December–May), as it molts remiges from April–August.<ref name=":1" /> This is also supported by possible damage from a nesting cavity in a female specimen collected in early June.<ref name=":1" /> It is presumed to breed in cavities as do other forest-falcons.<ref name=":1" /> ''M. mintoni'' has a generation length of 8.6 years.<ref name=":3" />

=== Species density === The density of this species is believed to be similar to that of the lined forest falcon, at 1 pair per 20–67 hectares.<ref name=":1" /> However, densities as high as 3–4 pairs per kilometer have been reported at dawn during the dry season.<ref name=":1" />

=== Movement === The cryptic forest falcon is believed to be sedentary. It is not migratory.<ref name=":1" />

== Threats and conservation status == The IUCN classified the cryptic forest falcon as least concern in 2016, which is consistent with its 2004, 2008, 2009, and 2012 assessments.<ref name=":3" /> This is largely due to its extremely large range.<ref name=":3" /> This range however, is decreasing. An analysis of forest cover change from 2000 to 2012 showed that this species lost 22% of its habitat within three generations, leading some to believe it should be considered globally Near Threatened.<ref name=":1" /> While its population size hasn't been quantified, it is believed to be decreasing.<ref name=":3" /> This decrease is largely based on its habitat loss due to deforestation.<ref name=":3" /> It is suspected to lose 34-51% of its habitat over three generations (26 years).<ref name=":1" /><ref name=":3" />

=== Atlantic rainforest population === The population in the Atlantic rainforest was believed to be critical or extinct upon the species classification, due to habitat loss in that region, as well as no specimens being collected after 1933 (originally classified as lined forest falcons, later recognized as cryptic forest falcons).<ref name=":0" /> Until 2012, when it was rediscovered in Southern Brazil.<ref name=":2" /> Further research is needed to quantify this population and its remaining range in the region.<ref name=":1" /> This population is likely critically endangered.<ref name=":1" />

== History == Specimens of the cryptic forest falcon were historically categorized as lined forest falcons.<ref name=":1" /> It was first recognized as a new species by Andrew Whittaker in 2002 when he heard its distinctive vocalizations.<ref name=":0" /> Museum specimens verified that it also slightly differed from other members of the genus in physical characteristics.<ref name=":0" /><ref name=":1" /> Whittaker subsequently named the species ''Micrastur mintoni<sub>,</sub>'' in memoriam of shore-bird ornithologist Clive D. T. Minton, Whittaker's mentor.

==References== {{Reflist}}

Category:Micrastur Category:Birds of Southern Amazonia Category:Birds of the Atlantic Forest Category:Birds described in 2003 Category:Taxa named by Andrew Whittaker (ornithologist) Category:Taxonomy articles created by Polbot