Nombre en español: Halcón-montés de Munchique

Nombre en inglés: Plumbeous Forest-Falcon

Nombre científico: Micrastur plumbeus  

Familia: Falconidae

Categorías: En Peligro (EN) / Casi endémico

El halcón montés plomizo​ o halcón montés de Munchique (Micrastur plumbeus)​ es una especie de ave accipitriforme de la familia Falconidae endémico de Colombia y Ecuador.

Descripción

Es un halcón pequeño que mide entre 30 y 36 cm de longitud. Las partes superiores de su cuerpo son de color gris mientras que las inferiores son blancas con finas franjas horizontales negras. El halcón montés plomizo junto al halcón montés cabecigrís y el halcón montés críptico forma un complejo críptico de especies. Los adultos de estas tres especies tienen el lorum pelado de color anaranjado, del mismo color que la cera, lo que los diferencia del halcón montés agavilanado. El halcón montés plomizo presenta una sola línea blanca en la cola además del borde blanco, como el halcón montés críptico, mientras que el halcón montés cabecigrís tiene dos líneas. El iris de sus ojos de color pardo grisáceo claro.

Distribución y hábitat

Es endémico de las selvas húmedas del suroeste de Colombia y el noroeste de Ecuador.

Libro rojo de las aves de Colombia Vol. I

Ecología

Esta especie se distribuye en la vertiente occidental de la cordillera Occidental colombiana, en los departamentos de Cauca, Chocó, Nariño y Valle del Cauca y en el noroccidente de Ecuador, en las provincias de Esmeraldas y Pi-chincha (Hilty y Brown 1986; Ferguson-Lees y Christie 2001; BirdLife 2009; GRIN 2010). Nunca ha sido hallada fuera del bosque maduro (Márquez et ál. 2005, Salaman 1996). En el piedemonte nariñense, parece ser común que se encuentre entre 200 y 1500 m (Salaman com. pers. en Márquez et ál. 2005).
Se alimenta de mamíferos pequeños, reptiles e invertebrados (Renjifo et ál. 2002, Márquez et ál. 2005; GRIN 2010; Salaman 1996). Existe poca información sobre su biología reproductiva (Thorstrom et ál. 1990); en la RN Río Ñambí el periodo reproductivo inicia al final de la temporada lluviosa en enero y finaliza con el comienzo de la temporada seca en julio (Salaman 1996).

Población

La densidad poblacional en la RN Río Ñambí se estimó en una pareja por cada 40 a 50 ha de bosque (Salaman 1996). Ferguson-Lees y Christie (2001) creen que su población total no supera 999 individuos, pero BirdLife Internacional (2013) estima de 6000 a 15 000.

Amenazas

Se cree que su población está declinando (Ferguson-Lees y Christie 2001) debido a la fragmentación del bosque (BirdLife 1992), en especial por los proyectos de construcción de carreteras, los cuales traen consigo la colonización y deforestación (Salaman y Stiles 1996).

Medidas de conservación tomadas

Se encuentra en el Apéndice II de CITES, en los PNN Farallones de Cali y Munchique y en las reservas de Río Ñambí y El Pangán (Renjifo et ál. 2002; Franco y Bravo 2005).

Plumbeous forest falcon

The plumbeous forest-falcon (Micrastur plumbeus) is a bird of prey in the family Falconidae only found in the Chocó region in Colombia and Ecuador. This rare bird has not been often spotted, which makes its study complicated. For a long time, it was considered to be part of the lined forest-falcons but it now known to be a species of its own. It is currently considered a vulnerable species because of the precarity of its habitat that is threatened by deforestation.

Description

The adult plumbeous forest-falcon has a grey back and a grey head with very bright orange legs and face. Their breast is barred and paler than their back, and their belly is more whitish towards the tail. This raptor has a black tail with a white tip and a white band in the middle, going across the whole width. Their irides are dark brown. The individuals are 30-34 cm (13 in) long and females are bigger than males. As a matter of fact, females weigh 180-213g and males weigh 172-188g.

Immature individuals look similar besides a whiter breast and beige-ish irides, clearer than in mature individuals.

Forest-falcons usually have long tails and round wings, but the plumbeous forest-falcon has a shorter tail and long wings.

Taxonomy

For some time, it had been debated whether the plumbeous forest-falcon was a lined forest-falcon (Micrastur gilvicollis) or a subspecies of the latter because of their resemblance. As it turned out, these birds were two different species. Their territorial distributions are completely separate.

M. plumbeus and M. ruficollis interestes live in the same environment but do not interbreed, or even interfere with each other. They are sympatric and syntonic. The plumbeous forest-falcon differentiated about 3 million years ago after the split between trans- and cis-Andean South American populations. The closure of the Panama seaway, due to a drier and cooler climate linked to the formation of ice sheets at higher latitudes, may have highly contributed to the isolation of the plumbeous forest-falcon. 

Forest-falcons are part of the sub-family Herpetotherinae. This clade’s and Polyborinae’s species are usually found in forests and wetlands.

Habitat and Distribution

The plumbeous forest-falcon is endemic to the south of the Chocó region in South America. This region extends in the south-west of Colombia and the north-west of Ecuador. This bird lives all-year long in forest lowlands and foothill forests; it is not a migratory bird. The elevation of its habitat varies from the sea level to approximately 1500m of altitude. One research project studying a few pairs of this species found that their territory extended over 35-40 ha.

Conservation status

This species has been classified as vulnerable by the IUCN because of habitat loss. Deforestation is touching more territories and the plumbeous forest-falcon’s habitat is being destructed. It is an unprotected species that needs to be studied more extensively to help its conservation. Efforts should be focused on the Chocó area where this organism is solely contained.

Behavior

Vocalizations

Two main types of vocalizations are known for this bird. They produce some yapping kew notes every 1.5 – 2.5s, as well as series of cah cah cah-cah-cah that may be sung by pairs.^[2] Three types of calls and songs are known for the forest falcons. The most common one is the «territorial advising song». The plumbeous forest-falcon repeat series of five notes to claim his territory. Furthermore, the «excited cackling call» and the «quacking song» are also heard from Micrastur species, even though less often then the first call. Two members of the same species sometimes sing in a pair.

Diet

Due to the lack of study, the diet of this forest-falcon is not perfectly known. However, it is most probable that it is an opportunistic predator feeding on small vertebrates and large invertebrates. Land crabs, birds and lizards were found in the digestive system of a few individuals. Its main source of food is thought to be lizards. Moreover, this family of birds prey on forest-dwelling birds and rodents.

They have two principal ways to forage. With the first one, they remain on the ground while running after the prey that they eventually catch with their feet. They keep their tail high when they chase the prey. The second technique consists of being perched about 2m above the ground, looking for sounds and movements in the leaf litter and then jumping on the detected prey.

Reproduction

The plumbeous forest-falcon’s reproduction is not really known but it probably sets up its nests in tree cavities. As a matter of fact, other members of the Micrastur family that have been more studied, such as the collared forest-falcon and the barred forest-falcon, nest in trees.^[

Fuentes: Wikipedia/eBird/xeno-canto