Formerly known as the magnificent hummingbird, Rivoli’s hummingbird (Eugenes fulgens) is a large species of hummingbird found in the mountainous forests of the Southwest down through Central America. Their radiant colors and flying prowess is a delight to watch. Read on for more amazing facts about this beautiful bird.
These gorgeous birds were named after the second Duke of Rivoli, an Italian nobleman who was an amateur ornithologist. In 1829, Rene-Primevere Lesson, a naturalist and surgeon gave the species their name to honor the Duke’s ornithological pursuits.
Rivoli’s hummingbirds are among the largest found north of Mexico. Measuring up to 4.3-5.5 inches long, they are second only to the blue-throated hummingbird in size. Their wingspan is up to 7.1 inches, and they weigh between 6 and 10 grams.
The primary source for Rivoli’s hummingbirds is nectar from flowers, particularly plants in the nightshade or lily families.
Some of the Rivoli’s favorite flowers are agave, butterfly bush, Indian paintbrush, salvia, fuchsia, columbine and penstemon. However, they also visit hummingbird feeders, taking advantage of the easy-to-access food. Rivoli’s hummingbirds have been known to consume “honeydew” excreted by some species of scale insects and will also supplement their diet by feeding on small insects and spiders.
The high metabolism of these tiny birds requires them to consume more than their own body weight in nectar each day. To do this, they will often fly from flower to flower rapidly and can visit up to 1000 flowers a day while searching for food.
Testament to this high metabolism is their record for the fastest heartbeat of any living vertebrae. Their tiny heart can beat from 420-1200 times per minute.
Rivoli’s hummingbirds have been found to host a unique species of flower mite in their nasal cavities.
These birds can be found in the mountainous regions of the Southwest, preferring oak, pine, and fir forests. They have been found at altitudes ranging from 5,000 to 9,000 feet. However, they are attracted to areas where flowers are abundant, preferring forest edges, meadows, and clearings.
Rivoli’s hummingbirds are also regular visitors to flowering gardens, where they can access nectar and insects to feed on.
Female Rivoli’s hummingbirds construct their nest alone, often on overhanging branches farthest from the tree trunks. The nests are tiny and cup-shaped and can be difficult to spot.
They are made of plant down and spider webs lined with soft moss for insulation. Rivoli’s hummingbird nests may be built overhanging streams, rivers, or waterfalls, adding an extra layer of protection for the eggs and hatchlings.
Unlike other species of hummingbird, male Rivoli’s hummingbirds do not perform elaborate courtship displays. Males abandon the female once copulation is complete, and the female is left alone to incubate the eggs and raise their young.
Rivoli’s hummingbird hatchlings are born without feathers, and with closed eyes, so they are completely helpless at birth. The female feeds the young a mixture of nectar, insects, and other proteins to help them grow. After a few weeks, the young birds will leave the nest and take flight.
Rivoli’s hummingbirds are easily identified by their iridescent purple crowns on the males. The feathers of the crown and throat shimmer in shades of metallic blue, green, and violet when viewed from different angles. Male birds also have a bright blue-green gorget.
Females have a duller coat of greenish-brown coloration, with a pale throat and belly, and lack the purple head feathers. Both sexes have a white stripe behind the eyes. Juvenile birds resemble the females, but darker and with a browner hue. Their color shades get more defined as they reach maturity. Female birds are also slightly smaller than males.
When foraging, Rivoli’s hummingbirds will create a “trapline” between flowering plants to maximize their food intake. This process involves traveling from one flower to the next in an organized and systematic way, allowing them to keep track of which flowers have been visited and when they should return. This way they don’t expend energy revisiting a flower too soon, that hasn’t had time to produce more nectar.
They are fast feeders, using their specialized long beaks and tongues to quickly access nectar from deep within the flowers. They may also hover over the flower while feeding, allowing them to reach nectar inaccessible by other birds.
Rivoli’s hummingbirds can also use their feet to perch on thin branches or wires for long periods of time, allowing them to scan for potential food sources.
Torpor, or a state of inactivity and deep sleep, is an adaptation used by Rivoli’s hummingbirds during cold nights. During this time, the birds lower their heart rate and body temperature to conserve energy.
As can be the case with many birds, classification gets tricky and changes with time. Historically they were called magnificent hummingbirds, but enough regional differences were noted that they were viewed as having two sub species. In 2017 they were officially split into two distinct species, the Rivoli’s and Talamanca. Rivoli’s reach from the southwestern U.S. to Honduras and Nicaragua, while the Talamanca hummingbird is found in Costa Rica and Panama. There seems to still be debate today, as some texts still list as one species, the magnificent hummingbird.
