Mangrove hummingbird (Amazilia boucardi)
|Spanish:||Amazilia de Manglar|
|Size||Head-body length: 10 – 11 cm (2)|
Average weight: 4.5 g (2)
Classified as Endangered (EN) on the IUCN Red List (1) and listed on Appendix II of CITES (3).
Endemic to Costa Rica’s mangrove forests, the strikingly plumaged mangrove hummingbird has beautiful bronze-green upperparts, and a glittering bluish-green breast. This contrasts with the pale white colouration of the belly that extends to the underside of the forked tail. The crown, rump and tail all have a slight bronze tinge to the plumage, and the medium-sized black and red bill has a downward curve (2). The female is similar to the male, but has a scattering of small green spots around the throat and more extensive white on the undersides (4). Young mangrove hummingbirds resemble the adult female, but have a greyish belly (2). The narrow wings of the mangrove hummingbird are adapted for hovering, and the legs and feet are small and weak, a feature hinted at in the name of the order, Apodiformes, which means footless (5).
The mangrove hummingbird is only found on the Pacific coast of Costa Rica, and ranges from Nicoya Peninsular, south to the Golfo Dulce. It is found in four or five large mangrove forests across its range, and appears to have a somewhat patchy distribution, even in areas of apparent suitable habitat (4) (6).
As its common name suggests, the mangrove hummingbird is typically found in mangrove forests. It is most abundant in mangroves with extensive stands of the tea mangrove (Pelliciera rhizophorae), but may also be found in bordering areas of secondary forest (4) (6).
The diminutive hummingbirds display remarkable manoeuvrability in flight, capable of hovering whilst feeding, with up to 200 wing beats per second. Owing to this energy demanding behaviour, hummingbirds feed almost exclusively on nectar, the carbohydrate-rich sugar secretions of plants, and feed from as many as 1,000 to 2,000 flowers each day. Hummingbirds also have the highest oxygen requirement of any vertebrate and, as a result, have uniquely structured lungs that enable them to breathe at a rate of up to 500 breaths per minute. These physiological adaptations have allowed hummingbirds to occupy a vast array of habitats and altitudes throughout the Americas (7).
The mangrove hummingbird mainly feeds from the flowers of the tea mangrove, using its long, specialised tongue to collect nectar at the base of the nectaries. It will also alight upon a perch in the lower or middle levels of the mangrove, and make repeated forays to catch small insects, such as mosquitoes, from the air (2) (4). The mangrove hummingbird breeds between October and February, and, in common with other hummingbirds, males will attract partners with elaborate courtship displays (4) (7). Although aggressive to unknown birds, unlike many other hummingbird species, male mangrove hummingbirds do not appear to defend territories (7) (8). Males probably mate with several females, with each female solely responsible for the construction of the cup shaped nest (4) (7). The nest is typically placed on mangrove twigs, one to four metres above the water, and is constructed with spider web, lichen and plant down. The female is also solely responsible for incubating the clutch of two eggs (4).
The mangrove hummingbird is almost totally restricted to mangrove forests in Costa Rica, a habitat that has been seriously depleted, and consequently, it is extremely vulnerable to further habitat loss (8) (9). Although it is illegal to destroy mangrove forests in Costa Rica, laws are largely ignored, and the entire Pacific coast of Costa Rica is under significant pressure from coastal developments for industry and tourism (4). Large tracts of mangrove forest have been cleared to make room for salt extraction and shrimp ponds, while the wood may be exploited to produce charcoal. Mangroves are also threatened by agriculture and urban encroachment, pollution, and by dyke and road construction, which affect the water hydrology (8) (10).
Restricted to a dwindling habitat in a single region, the survival of the mangrove hummingbird is dependant upon the implementation of major conservation measures (1) (6). Fortunately for this species, a wealth of conservation initiatives have been proposed, including further studies into its ecology and status, the establishment of protected areas and the development of a conservation action plan (4) (6). The mangrove hummingbird is also afforded a degree of sanctuary in the Tivives Biological Reserve, while a substantial population is believed to reside in Estero Guacalillos Biological Reserve (6) (8).
For more information on the mangrove hummingbird, see:
For more information on this and other bird species please see:
- BirdLife International:
Authenticated (23/06/2010) by David A. Luther, Research Associate, Smithsonian Migratory Bird Centre, Smithsonian National Zoological Park, Washington.
- Endemic: a species or taxonomic group that is only found in one particular country or geographic area.
- Incubate: to keep eggs warm so that development is possible.
- Nectaries: nectar-secreting glands, typically located at the base of insect-pollinated flowers. They usually attract insects to flowers, but can also attract seed dispersing insects.
- Secondary forest: forest that has re-grown after a major disturbance, such as fire or timber harvest, but has not yet reached the mature state of primary forest.
IUCN Red List (March, 2010)
- del Hoyo, J., Elliott, A. and Sargatal, J. (1994) Handbook of the Birds of the World. Volume 5: Barn-Owls to Hummingbirds. Lynx Edicions, Barcelona.
CITES (March, 2010)
Neotropical Birds (March, 2010)
- Erritzoe, J. (1993) The Birds of CITES and how to identify them. The Lutterworth Press, Cambridge.
BirdLife International (March, 2010)
- Perrins, C. (2009) The Encyclopedia of Birds. Oxford University Press, Oxford.
- BirdLife International (2002) Threatened Birds of the Americas. Birdlife International, Cambridge, UK.
BirdLife International EBA Factsheet (March, 2010)
WWF Ecoregions (March, 2010)