The yellow-crowned bishop (Euplectes afer) is a species of passerine bird in the family Ploceidae native to Africa south of the Sahara. It is highly sexually dimorphic in its breeding season, during which the male adopts a distinctive yellow and black plumage, contrasting with the female's predominantly brown coloration. Three subspecies are recognised. The yellow-crowned bishop is 95 to 105 mm (3.7–4.1 in) in length and 15 g (0.53 oz) in weight. During the breeding season it is sexually dimorphic — that is, the observable characteristics of the males become more apparent. During the breeding season, the male has distinctive golden yellow and black plumage. The bill of both sexes is short and conical. The color of the male's bill is black during breeding season; by contrast, during non-breeding season, the male's bill is horn in color, as is the female's. The legs and feet are pinkish brown. The male has a black lower face, throat, breast and belly, a wide black collar on the back of the neck, and a brilliant yellow crown, forehead, and hindcrown. There is a yellow patch on the shoulder, and the rump and back are yellow. The wings and tail are brown. During non-breeding seasons the male plumage looks like the female plumage. The female yellow-crowned bishop has pale brown upperparts, with darker streaking. The eyebrow is paler and the underparts are off-white with fine dark streaks on the breast and flanks.
The Yellow-crowned Bishop is native to Sub-Saharan Africa and has been introduced to Puerto Rico and Jamaica in the West Indies (Camacho Rodríguez and others 1999, Raffaele and others 1998). The species was first recorded in Puerto Rico in 1971 (Raffaele and Kepler 1992). It is uncommon in Puerto Rico and has been observed mostly in marshes around San Juan, the Río Piedras Botanical Garden, Torrecillas, Cartagena Lagoon and the Agriculture Experimental Station at Lajas, fields around the Ponce airport, and in the Humacao Natural Reserve (Hernández-Machado 2003, Raffaele 1989a, Raffaele and others 1998, Rivera 2003, Salguero 2003). It is also found locally in the municipalities of Canóvanas and Río Grande, as well as the southwestern region of the island (Oberle 2018). This species is found locally in areas of high grasses and reeds near bodies of freshwater including along rivers and freshwater lagoons (Raffaele 1989a, Raffaele and others 1998), as well as marshes and shrubby fields (Oberle 2018). The atlas fieldwork yielded a total of 21 records within six hexagons or 1 percent of the 479 total hexagons (see map). Of the six hexagons where this species was found, breeding met the atlas definition of confirmed in 17 percent (one) of the hexagons and probable in 83 percent (five) (see map). Yellow-crowned Bishop distribution. The map shows the highest breeding code by hexagon and overlaying the ecological life zones in Puerto Rico. Note: percentages may not total 100 due to rounding. 235Yellow-crowned Bishop/Napoleón Tejedor
Previously published reports indicate that the Yellow-crowned Bishop breeds between June and October (Raffaele and others 1998). Atlas results indicate that bishop breeding peaks in June through August, although evidence for some breeding was found in other months (see chart). Most breeding occurs in the subtropical moist forest life zone (see map and table). Results suggest that this species breeds mostly within the subtropical moist forest life zone (83 percent of the hexagons) (see table and map).
The global population size of the Yellow-crowned Bishop has not been quantified or assessed, but the species is described as common (Urban and others 2004). Due to the lack of evidence for any declines or substantial threats, the current population trend is suspected to be stable. This species is currently listed as a species of least concern by the IUCN (BirdLife International 2018). Locally, this species is not listed in any of the threatened categories of PRDNER and USFWS. In Puerto Rico, the Yellow-crowned Bishop has a protected habitat in land of 10 percent or 15 km2 of the total area covered by the hexagons where evidence of breeding was found for this species (143 km2).