Language English White-necked jacobin Photo: Espace pour la vie (Claude Lafond) Photo: Biodôme OngletsDescriptionDistinguishing featuresThis species is no longer at the Biodôme. The male has flashier colouring than the female. The male's head is bright blue. It has a relatively visible black eye mask, and a crescent-shaped white spot on the nape. Its back and sides are greenish, with white underparts. The white tail feathers are tipped with black. The wings are marked with greenish-blue shoulder patches and purple and white feathers visible in flight. The female has a greenish head, back and sides. There is a small white spot under the eyes. The white throat and belly are mottled with black. The tail is black. Females may sometimes have the same colouring as males, but can be distinguished by their longer beaks and shorter wings and tails. The beak in both sexes is black, long and slightly downturned at the tip. Immature males resemble females. ReproductionThe breeding period for white-necked jacobins is during the dry season, from June to December in Trinidad and Tobago. The males take on brilliant colouring at that time and put on impressive flight displays to attract a female. A male will shoot up into the air, fan out its tail, and then slowly descend as it steadily turns. Such displays can take the male as high as the top of the canopy. White-necked Jacobins nest in the forest understorey, 1 to 3 metres above the ground. The shallow nest is made of plant fibre bound together with cobwebs. It expands as the chicks grow, because the highly flexible cobwebs stretch easily. The nest is built on the surface of a leaf, sheltered under another larger leaf. The female usually lays two white eggs. DietLike other hummingbirds, white-necked jacobins feed mainly on nectar. Their long beaks reach easily into flowers, allowing them to sip the sugar-rich nectar. They also eat insects that they catch in flight. They sometimes hover over a swarm of insects, picking them off one by one, and occasionally pluck insects from leaves or branches. Insects are an important source of protein for them, especially popular during the moulting and breeding period. A nesting female may catch up to 2,000 fruit flies a day. PredatorsNear people's homes, white-necked jacobins fall prey to house cats. They are also attacked by various birds of prey and different species of snakes. When hunting for cobwebs to build their nests, they sometimes get caught in a web. When they are bathing or if they venture too close to the surface of a lake or stream, large fish may occasionally leap out of the water and snatch them. The eggs and chicks still in the nest are vulnerable to small carnivorous mammals, other birds and snakes. Frogs, praying mantises, bees and wasps will also sometimes attack white-necked jacobins. HabitatWhite-necked jacobins frequent the canopy. They are found in clearings and in and along the edges of low-lying rainforests, at altitudes below 900 m. They also live in coffee and cacao plantations. White-necked jacobins are found from southern Mexico to central Brazil and southern Bolivia. They are also observed on some islands, including Trinidad and Tobago. Ecology, behaviourWhile these birds are normally solitary, they sometimes gather around a flowering tree. When they insert their beaks into the corollas to gather nectar, pollen clings to their breasts. This fertilizes the flowers as the pollen is transferred from one to the next. White-necked jacobins play an important role in pollinating trees and regenerating the forest. Hummingbirds are aerial acrobats. They can fly both forwards and backwards and even hover in place. Their wings beat 50 to 80 times a second. Their stability in flight and tremendous control allow them to hold steady in front of a flower as they precisely aim their long beaks inside. Battles marked by a variety of small vocalizations occur when too many of these birds try to browse on the same flower. Some researchers have found that the calls of some tropical hummingbirds correspond to certain messages and have hypothesized that these species may have a language. French nameColibri jacobin Scientific nameFlorisuga mellivoraPhylumChordataClassBirdsOrderApodiformesFamilyTrochilidaeSize11 to 12 cmWeightMale: 7.4 g Female: 6.5 gStatusLeast concern (UICN), relatively common.