The Puerto Rican Mango Hummingbird (Anthracothorax portoricensis) is a small hummingbird endemic to the island of Puerto Rico. With an average body length of 7-8 cm and weight of 3-4 g, it is one of the smallest hummingbird species in the world. This colorful bird has green upperparts and white underparts, with the male displaying an iridescent reddish-violet throat patch, known as a gorget. The Puerto Rican Mango gets its name from its affinity for nectar from the flowers of the Puerto Rican Mango tree.
Range and Habitat
The Puerto Rican Mango is restricted to the main island of Puerto Rico and smaller nearby islands like Vieques, Culebra and Mona. It occupies a wide range of habitats including forests, woodlands, plantations, gardens and mangroves from sea level up to altitudes of 1200 m. It prefers areas with a prevalence of flowering plants and trees where it can easily source nectar. Key nectar plants include species from the genera Inga, Calliandra, Erythrina, Pedilanthus, Agave and Aloe.
Diet
As with all hummingbirds, the Puerto Rican Mango subsists primarily on nectar from flowers. It uses its specialized long bill and tongue to drink nectar while hovering in front of the flower. Preferred nectar sources are tubular flowers with colors in the red-orange spectrum. The Puerto Rican Mango also consumes small insects like flies, beetles and spiders to meet its nutritional needs for protein. A technique called “hawking” involves the hummingbird catching insects in mid-air. The diversity of nectar plants flowering throughout the year allows the Puerto Rican Mango to find food sources all year round. This is essential since hummingbirds need to eat at frequent intervals to power their rapid metabolism.
Behavior and Ecology
The Puerto Rican Mango Hummingbird is a solitary and territorial species. Males are highly aggressive and will defend nectar-rich flowering trees or patches from intrusion by other males or females. They perform aerial displays and exert their dominance by vocalizations. Males also defend territory for nesting and mating. Females build a small cup-shaped nest out of plant down, spider webs and lichens on the upper surface of a leaf towards the tip of a branch. Two pea-sized white eggs are laid and incubated for 15-19 days. The chicks fledge in about 3 weeks. The Puerto Rican Mango breeds primarily from March to June.
Like all Caribbean hummingbirds, the Puerto Rican Mango played an important role in pollination of native plant species. Their ability to hover allows them to access tubular blossoms not reachable by insects. As they move from flower to flower feeding on nectar, pollen gets deposited on their head and body and transported to the next blossom. However, habitat loss due to development is impacting floral diversity and threatening this critical ecosystem service.
Threats and Conservation
Widespread urbanization and agricultural expansion has led to loss and fragmentation of forests in Puerto Rico, greatly reducing available habitat for the hummingbird. Use of pesticides and herbicides also decreases insect and plant food sources. Competition from alien bird species like the Green Mango and Red-billed streamertail may also negatively impact the native Puerto Rican Mango. It has disappeared from some parts of its former range like Isla de Mona.
Protecting remaining old growth and secondary forests is crucial for conservation of the species. Planting native trees and flowers in home gardens and urban greenspaces can also help provide habitat. Creating hummingbird friendly spaces with nectar plants and feeders can allow observation and connection with this diminutive and fascinating bird. More research on population distribution, breeding ecology and habitat use is also required to devise targeted conservation action plans. The brilliant Puerto Rican Mango Hummingbird serves an important role in its island ecosystem which must be preserved.