Blue-capped manakin

Appearance

Blue-capped manakins show sexual dimorphism in weight and wing chord length. Females are heavier at 9.8 g on average with a max weight of 11.5 g and a minimum weight of 8.5 g. Males are 8.5 g on average with a maximum weight of 9.5 g and a minimum weight of 7.5 g. Males have a wing chord length of 60.45 mm on average with a maximum length of 63 mm and a minimum length of 58 mm. Females have a wing chord length of 58.76 mm on average with a maximum length of 62 mm and a minimum length of 55 mm.

Males are sooty black with a bright blue crown while females are green. Juvenile plumage is similar to female plumage but is duller in color. Their first prebasic molt occurs within 2 months of leaving the nest and is a partial molt. Their second prebasic molt occurs at the end of the first breeding season or one year after their first prebasic molt. This molt is complete, so they lose their molt limits. At this stage, males gain signs of male plumage. The third prebasic molt occurs at the end of their third year and males gain full male plumage.

Distribution

Blue-capped manakins live in terra firme forest understory of South America.

Status

The blue-capped manakin has least concern conservation status. A major factor in this decision is its large range of 5,050,000 km2. Its population size is unknown, but has a decreasing trend.

Habitat

Blue-capped manakins live in terra firme forest understory of South America.

Reproduction

Breeding season coincides with the dry season. Males are known to display alone or form leks of up to seven males. Adult and juvenile males form territories though juveniles are unable to maintain their own territory. Their territories range from 206 to 5045 m² in size. They defend their territory and attract mates through song. They perform their songs on song perches that are horizontal or slightly angled twigs and will sing between 6am and 5pm. Their display courts are 3–5 m in diameter and are located close to the ground in the open understory. They use up to two courts at a time, but courts can change location annually. Their courtship displays are somewhat complex with a total of 11 behaviors, 6 of which are aerial. Female's home ranges average 4 ha in size and overlap with one lek on average.

Blue-capped manakins make simple, open-cup nests using dry palm, dry leaves, and/or bark externally. The internal lining of their nest is pale brown, but can also be whitish or yellow. They use spider webs to secure their nests to the tree. They chose small shrubs and treelets that are less than 1 meter tall and place their nests on horizontal forks. They typically nest in "Rudgea spp.", "Ixora killipii", "R. viridifoliax", and "R. lindenicana" along small ravines. Females are the sole nest builders and take care of their offspring alone. They lay two eggs per clutch. Their nests experience high predation rates. To help mitigate this risk, Blue-crowned manakins choose nesting sites away from wire-tailed manakins, a species that favors similar nesting environments. This reduces the number of birds nesting in one area and thus reduces the chance that predators will predate the area.

Food

Blue-capped manakins are frugivores. Their diet includes fruit from "Melastomataceae", "Moraceae", "Bromeliaceae", and "Araceae".

When feeding in a mixed flock, blue-capped manakins tend to flock with cinereus and dusty-throated antshrikes, and the white-flanked, Yasuni, long-winged, gray, and rufous-tailed stipplethroats. These flocks are typically only composed of one or two blue-capped manakins. When there are two blue-capped manakins in a flock, they forage independently from one another. Their behavior is never aggressive toward other species of birds in the flock. Both males and females forage in mixed flocks, but females spend more time on average in the flock. They forage in the understory between a height of 2–7 m. Their preferred food while in flocks are arthropods, including ants, flies, and other small insects. While catching arthropods, their hunting technique was often a sally-strike or sally-glean off of live foliage. Considering their normally frugivorous diet, it is speculated that the blue-capped manakins are taking advantage of the flock's ability to cause insects to scatter.

Predators

Blue-capped manakins experience high nest predation rates with 70% of nests failing due to predation. It is estimated that only 7.5% of nests successfully fledge young. It is uncertain how blue-crowned manakins maintain population size with such a low rate of success, but it has been speculated that high female survivability and multiple breeding attempts per season may be a factor.

Blue-capped manakins can get infected with haemosporidian parasites. A genetic study revealed that half of the sampled manakins were infected with blood parasites, representing nine different types. Young individuals had higher infection rates compared to adults.

Evolution

Blue-capped manakins vary genetically based on geographic location. Physical boundaries, such as large Amazonian rivers and the Andes Mountains, tend to separate genetically distinct blue-capped manakins. The uplift of the Andes Mountains seem to be the first major source of separation between blue-capped manakin populations followed by the establishment of Amazonian rivers. The Amazon River separates North and South Amazonian clades and the Napo River separates the North Amazon and Napo-Marañon clades. Large rivers present a barrier to Blue-crowned manakins despite being flighted because they prefer the understory of terra firme forests. Central Peru and South Peru/Bolivia clades and Venezuela and Amazonia clades are not separated by a geographic barrier. It is likely that they instead historically separated and evolved separately for a period of time.