Bird of the Month - November 2006
Purple-Throated Carib (Eulampis jugularis )
Name in French: Colibri Madère
Local names: many local variants exist, including variations of Madè, Fou-fou, Fal-wouj, Doctor Bird, Ruby-throat, etc. Most local names are shared with other hummingbirds.
The Purple-Throated Carib is a large, beautifully colored hummingbird found on most islands of the Lesser Antilles. This species in endemic to this area, which means that it is not found outside the Lesser Antilles.
- Adult: At 11.5 cm (4.5 inches) this is one of the larger hummingbirds. It is mostly black, with emerald green wings and tail, bluish rump, and iridescent purple throat and breast. The bill is all black, long, and down-curved. Both sexes have the same coloration, but the female’s bill is longer and more sharply down-curved than the male. The male is larger than the female.
- Immature: The bill is shorter and there are scattered brown feathers on the upperparts with some orange feathering on the throat.
- Voice: Utters a sharp chewp, which is repeated rapidly when agitated.
- One common feature of hummingbirds is that they have iridescent colors, colors that arise through interplay between structural features of their feathers and the light. Depending on the direction of the light, the iridescent throat can appear brilliant purple, dull purple or black.
- Like all hummingbirds, this species eats nectar from flowers (and feeders if available) and insects. In Dominica, it is regularly seen catching flying insects much like a flycatcher; this behavior is not universal for hummingbirds.
- Nesting takes place between January and July. A cup-shaped nest normally containing 2 white eggs is hung from a fork of a small branch between 3 and 18 meters (9 and 60 feet) above ground.
- In addition to the common method of aggression in hummingbirds (a chase), some species have a threat display, which varies among species. In Purple-Throated Carib the bird assumes a stance with the body horizontal and wings perpendicular to the body and held somewhat down. In this stance, the bird points its bill towards the intruder and shakes, sometimes also moving the head from side to side. This may symbolize flight without expending the same amount of energy.
Range and Habitat Needs
- A bird entirely of the Lesser Antilles—a fairly common resident in St Barthélemy, Saba, Guadeloupe, Dominica, Martinique, St. Lucia, St. Vincent and Grenada while it is uncommon on St. Eustatius, St. Christopher, Nevis, Antigua, and Montserrat and a vagrant on some surrounding islands, such as US Virgin Islands, Barbados and The Grenadines.
- At least on Dominica it is found from near sea level (less common) to very high into the mountains. It likes forested areas and banana plantations but also frequents some semi-open areas as long as suitable food sources exist. It is generally expected to prefer mountain forests rather than sea level.
Threat display in a male Purple-Throated Carib defending his favorite source of food. The display can last shorter or longer, but often is followed by the more traditional chase.
- Male Purple-Throated Caribs are larger than females, but the bill of the female is 30% longer and twice as curved as the bill of the male. This sexual dimorphism (different morphology of males and females) has been shown to be related to the feeding ecology of each sex (Temeles and Kress 2003, Altshuler and Clark 2003). In St. Lucia, females prefer to feed on a species of Heliconia(H. bihai) that has a long curved corolla (flower structure that contains the nectar in these plants), while males prefer to feed on a Heliconia (H. caribaea) which has a shorter and straighter corolla. In areas where H. caribaea is rare or absent, H. bihai has evolved a different color flower morph (form) with a short and straight corolla (closely matching the shape of the male bill), evidence of a tight coevolutionary association between the Purple-Throated Carib and it’s Heliconia food source. A similar pattern has been found on Dominica but here the corolla of an H. Caribaea morph has become longer and more curved to match the shape of the female bill.
- In addition, H. caribaea yields more nectar per flower than H. Bihai, corresponding to the different body sizes of the two sexes. Male Purple-Throated Caribs, because they are 25% heavier than females, require more energy than females (just like larger cars consume more gas) and nectar production in H. caribaea nectar evidently meets this demand. Differing amount of nectar production in the two species of Heliconia may account for the different body sizes of males and females. This provides further evidence of tight coadaptation between the flowering Heliconia and it’s sole pollinator, the Purple-Throated Carib.
- Males and females employ different feeding strategies. Because they are heavier, males defend patches of their favorite flower (H. caribaea) from females. Females forage over greater distances in undefended patches, a method known as “traplining."
Threats and Conservation
- Birdlife International lists this species with status Least Concern.
- As long as a framework of forests with a variety of native flowers are available on each island (especially Heliconia species during the breeding season), this species should survive without difficulty. Damaging actions include forest clearing or conversion of low intensity farming to a more industrialized form. A catastrophic event like a hurricane could potentially damage the entire habitat on an island for this species.
- To ensure long-term survival, conservation measures should center on protecting existing forest habitat on islands in The Lesser Antilles. This would benefit not only the Purple-throated Carib, but also other Lesser Antillean forest birds, including a number of local endemics.
Where to Find More Information?
- Altshuler D.L., and C.J. Clark. 2003. Darwin’s Hummingbirds. Science 300: 588-589.
- Birdlife International Factsheet: Eulampis jugularis
- James, A., S. Durand, and B. Jno. Baptiste, 2005. Dominica’s Birds. Forestry, Wildlife and Parks Division, Dominica
- Raffaele, H., J. Wiley, O. Garrido, A. Keith, and J. Raffaele.1998. A Guide to the Birds of the West Indies. Princeton University Press, Princeton, NJ
- Temeles, E.J. and W.J. Kress. 2003. Adaptation in a Plant-Hummingbird Association. Science 300: 630-633.
- Purple-throated Carib Bird of the Month contributed by Niels Larsen. All photographs copyright Niels Larsen.