Yellow-shouldered Blackbird

The Yellow-shouldered Blackbird (Agelaius xanthomus) is a striking species of New World blackbird endemic to Puerto Rico and satellite islands like Mona^[1].

• Common Name(s): Yellow-shouldered Blackbird
• Family: Icteridae
• Body Dimensions: 20–23 cm
• Male Plumage Color(s): Black With Yellow Shoulder Patches Bordered White
• Female Plumage Color(s): Black With Yellow Shoulder Patches Bordered White
• Habitat: Dry Forests and Mangroves
• Diet: Insects
• Native Countries: Puerto Rico
• Continent(s): North America
• Taxonomy Classification Year: 1862
• Taxonomist(s): P.L. Sclater

Yellow-shouldered Blackbird Fun Facts

• Originally abundant in coastal forests, habitat destruction since the early 1900s decimated populations of this 20-23 cm long omnivore. Following the endangered species listing in 1976, recovery programs expanded the population to over 1,250 breeding pairs.
• With jet-black plumage offset by namesake bright yellow shoulder patches bordered in white, the Yellow-shouldered Blackbird frequents arid southwest forests and mangroves.
• Yellow-shouldered blackbird’s diet mixes insects gleaned from canopy branches with fruits and seeds.
• Monogamous pairs nest in cups placed along cliffs, trees, or artificial platforms from April to August, producing 1-4 blue-green eggs in a clutch.
• While preferred habitat loss to agriculture and development continues to hamper recovery, this species also suffers brood parasitism by Shiny Cowbirds infiltrating nests.
• Introduced predators like rats and mongooses plunder eggs and chicks. Avian pox outbreaks further threaten remaining strongholds on Mona Island and several southwestern Puerto Rican reserves to maintain the Yellow-shouldered Blackbird – however, only intensive management of this endangered species curbs sliding towards extinction.
• Safeguarding precious remnant nesting and foraging grounds remains essential for the Yellow-shouldered Blackbird’s survival. Cowbird trapping, rat control, habitat restoration around protected areas, and monitoring for diseases bolster recovery hopes.

But preventing habitat loss and fragmentation may determine whether these brilliant blackbirds retain wild strongholds or vanish as another endemic casualty.

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