The northern red bishop or orange bishop (Euplectes franciscanus) is a small passerine bird in the family Ploceidae. It is part of the largest genus in the family with over 60 different species. Its sister species is the Southern red bishop (Euplectes orix). This species is most recognizable by the bright reddish orange with contrasting black plumage displayed by the breeding male. It is most common throughout the northern African continent but has also been introduced to areas in the western hemisphere.
Taxonomy and systematics
The northern red bishop was first described by Paul Erdmann Isert in 1789 in Accra, Ghana. Euplectes directly translates to "good weaver," while franciscanus relates to the Franciscans, a religious order from the 12th century that symbolized the crimson color.
The northern red bishop was previously a subspecies of its neighboring species, the southern red bishop (Euplectes orix). Today, these two are classified as separate, distinct species; separated by the equator, the northern red bishop inhabits the northern continent of Africa, while the southern red bishop resides in the south. Molecular phylogenetic data in 2007 supported these two species as having a sister relationship. The northern red bishop is easily distinguished by the male's continuous red chin.
Its closest relative, aside from the southern red bishop, is the black bishop (Euplectes gierowii), native to sub-Saharan Africa. Lutein and two red fractions (R1 and R2) derived from lutein are the two dominating carotenoids that contribute to the bird's pigment in the wild. Northern red bishops held in captivity lack the R2 red fraction carotenoid from their diet. This plumage is present on the backside of the male and wraps around the chin to back of the head, throat, and breast, with a dark black crown, forehead, flank, and belly. The tail and upper wings are brown, with pale legs and a black bill.
This species was introduced to Puerto Rico in the 1960s, and has since been reported throughout the West Indies. The northern red bishop has been reported in Martinique, Guadeloupe, Barbados, Jamaica, and St. Croix, U.S. Virgin Islands, along with recorded occurrences in Cuba. In recent decades, the northern red bishop were introduced to areas of the United States, including southern California, Texas, and Hawaii. In 1997, the estimated population size of northern red bishops in Los Angeles and Orange counties reached 400, although this number has likely declined in recent years due to a loss of marshland habitat. The bright orange-to-yellow plumage with a contrasting dark black pigment is for attracting mates. The song pattern of the male during the breeding season is quite monotonous with minimal change from season-to-season, and males may not even sing at all in the nonbreeding season. Experiments into the neural relationship between song and plumage color revealed the hyperstriatum ventralis (HVc) and the robust nucleus of the archistriatum (RA) are neural structures involved in song control. Possibly due to higher androgen levels at the time, both the HVc and RA significantly increase in volume during the breeding season. Additionally, the sizes of these structures are significantly different between the sexes, with a male having a RA more than twenty times larger than the female. The ratio of sexual dimorphism in these structures are higher than that in other songbirds.
This species is polygynous, and males will often mate with up to six females, Males use their plumage for display-flight to attract females, while puffing their body plumage out. Once a female lands, courtship follows, resulting in males building globular nests for their mate. The females in turn line the nest for her future chicks.
Nests are generally made from multiple grasses and reeds placed within the marshy vegetation. The average clutch size in Africa is unknown, but in South Africa, the related southern red bishop averages between 2 and 3 eggs per clutch.