Bee hummingbird

Name and taxonomy

The scientific name of the bee hummingbird is Mellisuga helenae. The genus holds only one other bird. English speakers also use the name Helena hummingbird. The species name probably honours a woman called Helena. The Cuban name zunzuncito is a small word for a small bird. It probably copies the hum that the wings make.

The bird belongs to the hummingbird family, Trochilidae. That family sits in the order Apodiformes, alongside the swifts. GBIF records the species from Cuba and from almost nowhere else. iNaturalist holds 372 observations of the species. CITES lists the bird on Appendix II, which controls trade in it. Wikidata records the bird as endemic to Cuba. The order name Apodiformes means without feet, which probably points at the tiny legs of the group.

Evolution and relatives

The nearest relative is the vervain hummingbird, Mellisuga minima. The two birds are the only members of the genus. The vervain hummingbird lives on Jamaica and on Hispaniola. It grows to about 6 cm and weighs 2 to 2.4 g. Most lists put it second in the ranking of the smallest birds. Both members of the genus live on islands of the Greater Antilles. The vervain hummingbird is listed as Least Concern, and its numbers are steady.

Birds are the living branch of the theropod dinosaurs. No smaller bird and no smaller dinosaur has turned up as a fossil. Writers therefore call the bee hummingbird the smallest dinosaur of all. The bird and its flowers have shaped each other over a long stretch of time. Its flowers have no scent, carry bright colour, and form long narrow tubes with thin nectar.

Appearance

The male has a green crown and a red throat. In sunlight the throat burns scarlet, and long plumes stand out at each side. His back is bluish, and the belly and flanks are mostly grey-white. The female is blue-green above with a pale grey belly. White spots mark the tips of her tail feathers. The colours are iridescent, so they come and go with the angle of view.

Beside other small hummingbirds, the bird looks round and plump. The bill is straight, short and sharply pointed. Average length is about 5.82 cm and average mass about 2.28 g. Flight muscles make up 22 to 34 percent of the body weight. The breastbone keel is large and the wings taper to a point. The legs and feet are tiny, and they serve only for perching. A young bird looks much like an adult, but it lacks the dark tones and the bright trim. A male gains his decorative pattern later in life.

Habitat and range

The bee hummingbird is found on the Cuban archipelago and nowhere else. It occurs on the main island and on the Isla de la Juventud. Birds keep to thick growth that carries lianas and epiphytes. They use coastal and inland forest, mountain valleys, swampy ground and gardens. They may live high or low, but they seem to prefer the lowlands. Cuba is warm and humid all year, which probably suits a bird with no fat to spare.

The population is broken into patches across the island. One stronghold is the mogote country of Pinar del Rio Province. The Zapata Swamp in Matanzas Province holds more birds than most sites. That swamp is the largest protected area in the Caribbean, at over 6000 square kilometres. Ramsar named it a wetland of international importance in 1971. Eastern sites include Alexander Humboldt National Park, Gibara and the Sierra Cristal. Zapata lies under 150 kilometres southeast of Havana, and its highest ground reaches about 10 metres.

Diet and feeding

Nectar is the main food of the bee hummingbird. Observers have recorded it at ten plant species, and nine of those are Cuban natives. It also eats small insects and spiders, often picked out of a flower. It hovers in front of a bloom rather than perching on it. The long tongue flicks in and out to draw the nectar up.

One bird may call at 1500 flowers in a day. It eats close to its own body weight every day. Feeding takes up as much as 15 percent of its time. It prefers nectar that holds 15 to 30 percent sugar. Its flowers give no perch, so few other animals can reach that nectar. Pollen sticks to the bill and head, and the bird carries it to the next flower. The tongue is long, and the bird can push it out well beyond the bill.

Behaviour and social life

The bee hummingbird is active by day and lives alone outside the breeding season. It does not travel far, because Cuba stays warm through the year. Birds do shift about as local plants come into flower. A male holds a feeding patch and chases anything that enters it. He drives off rival males, bumblebees and hawk moths. Steep flights and threat displays settle most disputes.

Flight is the normal state of this bird. It passes a greater share of its life in the air than any other species. It can fly up, down, backwards and even upside down. The wings trace a figure of eight, which keeps the body in one place. The shoulder joint lets each wing turn through 180 degrees.

Cold nights are met with torpor. Body temperature falls from 41 degrees Celsius to about 30 degrees. The bird saves energy until the sun returns. Hummingbirds in general run the highest metabolism of any backboned animal. Their flight muscles use about ten times the oxygen of an elite human athlete.

Communication and senses

The song is a high, jumbled twitter. A male often sings from the top of the tallest tree in his patch. Many songs are one note repeated, and each note lasts under a second. Birds also squeak and warble. Different leks, and different males within one lek, vary the tune.

The pitch is high, and the sound is thin to a human ear. Sight probably matters most to a bird that hunts coloured flowers. The red throat only flares when light strikes it, so the male may aim his display. Chases and dives likely carry a message to a rival.

Reproduction and life cycle

Breeding runs from March to June. It starts as the wet season ends and the dry season opens, when many trees flower. Males gather in leks and sing to advertise themselves. A female visits several leks and picks a male on his performance. One male may mate with several females in a season. Mating happens on a perch or in the air.

The female builds the nest and raises the young without help. She weaves cobweb, bark and lichen into a cup about 2.5 cm across. She lines the cup with soft plant down. The nest sits 3 to 5 metres above the ground. Jucaro and young ocuje trees are the usual choice. Each nest serves for one brood only.

A clutch holds one or two eggs, and each egg is the size of a coffee bean. The female alone sits on them for about 21 days. Chicks hatch blind and almost bare. She feeds them by regurgitation while she hovers above the nest. Young birds leave about 22 to 24 days after hatching, once the wing feathers are full. Both sexes can breed at one year old, and wild birds live up to 7 years.

Predators and threats

Hawks, falcons and kestrels catch bee hummingbirds. Orioles, frogs, fish and large tropical spiders have taken them too. Speed and sharp turns are the main defence. The bird can stop dead in the air and back away. A nuptial dive of short downward dashes drives an intruder off the territory.

The loss of forest to crops is the biggest threat today. Clearing removes both the nest sites and the material for a nest. In the 19th century, stuffed hummingbirds were worn on hats as a mark of status. That fashion was the first heavy pressure people put on the family. A bird of this size probably loses many nests to storms as well. A nest 3 to 5 metres up may also be within reach of a climbing snake.

Population and conservation

The IUCN lists the bee hummingbird as Near Threatened. CITES gives it Appendix II protection. The sources give no firm count of how many birds remain. The range is small and broken, which probably raises the risk. Cuba aims to hold its yearly rate of deforestation at 0.1 percent.

A national reforestation plan began in 1959. Planting rose from 50.8 million trees a year in the 1960s to 136.3 million in the 1980s. The Zapata Swamp carries a biosphere reserve and two Ramsar listings. Alexander Humboldt National Park protects a second core area in the east. Those two sites probably hold the safest populations of the bird. The Zapata reserve alone carries over 900 native plants and 175 kinds of bird. A protected wetland of that size probably shelters many nesting trees.

Relationship with humans

The bee hummingbird does no harm to people or to crops. Farmers, scientists and visitors all stop to watch it. A garden can draw the bird with the right flowers or a feeder of sugar water. Hummingbirds pollinate farm crops as well as wild plants. Cuban plants such as the scarlet bush depend on this one bird.

Birdwatchers probably travel to Cuba above all to look for this species. As with other rare island birds, Zapata and Alexander Humboldt National Park are the usual places to look. The bird is likely impossible to keep at home, because its diet and its speed defeat a cage. The species costs farmers nothing, and no adverse effect on people is on record. The 19th-century hat trade is the only large-scale use people ever made of hummingbirds.

In culture and myth

In Cuban speech the bird is the zunzuncito, a name that names its own sound. The word is a double diminutive, and it probably began as an imitation of the wings. In English tradition the bird also carries a person's name, Helena. In modern science writing it appears as the smallest dinosaur that has ever been found. In 19th-century European fashion, whole stuffed hummingbirds sat on women's hats.

The Zapata Swamp is known abroad above all as the home of the smallest bird. As with other hummingbirds, popular writing treats the bird as a sign of lightness and speed. No hummingbird folklore came out of the web sources used for this page. The record for smallness appears to draw far more attention than any story about the bird. The vervain hummingbird of the nearby islands is often quoted beside it as the runner-up.