Invasive alien species (IAS) are species whose introduction and/or spread outside their natural past or present distribution threatens biological diversity. IAS occur in all taxonomic groups, including animals, plants, fungi and microorganisms, and can affect all types of ecosystems. While a small percentage of organisms transported to new environments become invasive, the negative impacts can be extensive and over time, these additions become substantial. A species introduction is usually vectored by human transportation and trade.
If a species’ new habitat is similar enough to its native range, it may survive and reproduce. For a species to become invasive, it must successfully out-compete native organisms, spread through its new environment, increase in population density and harm ecosystems in its introduced range. Ecosystems that have been invaded by alien species may not have the natural predators and competitors present in its native environment that would normally control their populations. To summarize, for an alien species to become invasive, it must arrive, survive and thrive.
Islands are especially vulnerable to IAS because they are naturally isolated from strong competitors and predators. Islands often have ecological niches that have not been filled because of the distance from colonizing populations, increasing the probability of successful invasions. Invasive Alien Species (IAS) is a critical issue in the Caribbean since it may impact
For a listing of IAS in Trinidad and Tobago, click here.
Identification:The oilbird is the only nocturnal, fruit-eating bird in the World.This is a large bird at 41-48 cm , with a wing span of 91 cm. It has a flattened, powerfully hooked bill surrounded by deep chestnut rictal bristles up to 5 cm long. It is mainly reddish-brown with white spots on the nape and wings. Lower parts are cinnamon-buff spotted with white. The stiff tail feathers are a rich brown spotted with white on either side.
The squabs become very fat before fledging, weighing up to half again as much as the adult birds do. They used to be harvested and rendered for oil, hence the name "oilbird".
Behaviour:The oilbird spends the daylight hours roosting or nesting in caves. At night, they forage in the surrounding forests for the fruit of palms, laurels, incense and camphor. They often fly as far as 120km from their cave in search of food. Although the Oilbird forages by sight, it is one of only a few birds, and the only nocturnal one, known to navigate by echolocation in sufficiently poor light conditions, using a series of sharp audible clicks for this purpose. It also produces a variety of harsh screams while in its caves; entering a cave with a light especially provokes these raucous calls. They also may be heard as the birds prepare to emerge from a cave at dusk.
Reproduction:Pairs are monogamous on a long-term basis. The female lays 1-3 eggs and these eggs hatch in about a month. It may take another six weeks to fledge the youngster which has no distinct juvenal plumage. Very young birds are very fat and full of oil. May and June are the months when the highest number of nestlings is to be found.
RANGE AND POPULATION
Population estimate:154 adults
Population trend:Stable
Country endemic:No
Range: Oilbirds live mainly in South America and are found in the countries of Guyana, Trinidad and Tobago, Venezuela, Colombia, Ecuador, Peru, Brazil, and Bolivia. Oilbirds also range in the Central American countries such as Costa Rica and Panama. It is a bird of tropical and subtropical primary forests.
The population is low in Trinidad and Tobago and vulnerable due to the specific feeding habits of the species, which feed on palm seeds, as well as their habitat. Living in caves places limitations on population size. Poachers are also another threat.
More accessible caves inhabited by the oilbird are under regular siege by poachers.
Identification:The oilbird is the only nocturnal, fruit-eating bird in the World.This is a large bird at 41-48 cm (16-19"), with a wing span of 91 cm (3 ft). It has a flattened, powerfully hooked bill surrounded by deep chestnut rictal bristles up to 5 cm (2") long. It is mainly reddish-brown with white spots on the nape and wings. Lower parts are cinnamon-buff spotted with white. The stiff tail feathers are a rich brown spotted with white on either side.
The squabs become very fat before fledging, weighing up to half again as much as the adult birds do. They used to be harvested and rendered for oil, hence the name "oilbird".
Behaviour:The oilbird spends the daylight hours roosting or nesting in caves. At night, they forage in the surrounding forests for the fruit of palms, laurels, incense and camphor. They often fly as far as 75 miles[A1] from their cave in search of food. Although the Oilbird forages by sight, it is one of only a few birds, and the only nocturnal one, known to navigate by echolocation in sufficiently poor light conditions, using a series of sharp audible clicks for this purpose. It also produces a variety of harsh screams while in its caves; entering a cave with a light especially provokes these raucous calls. They also may be heard as the birds prepare to emerge from a cave at dusk.
Reproduction:Pairs are monogamous on a long-term basis. The female lays 1-3 eggs and these eggs hatch in about a month. It may take another six weeks to fledge the youngster which has no distinct juvenal plumage. Very young birds are very fat and full of oil. May and June are the months when the highest number of nestlings is to be found.
Range: Oilbirds live mainly in South America and are found in the countries of Guyana, Trinidad, Venezuela, Colombia, Ecuador, Peru, Brazil, and Bolivia. Oilbirds also range in the Central American countries of Costa Rica and Panama, and the islands of Tobago[A3] and Aruba. It is a bird of tropical and subtropical primary forests.
More accessible caves inhabited by the oilbird are under regular siege by poachers.
CONSERVATION MEASURES
Current measures:The World Wildlife Fund made a substantial contribution toward the establishment of the Centre in order to protect the colony. This protection has been very successful, and Dunston Cave maintains a stable colony.
[A5]Seems to be very Asa Wright bias. I think the population is low in Trinidad and Tobago and vulnerable due to specific requirements of the species feeding on palm seeds and living in caves which would place limitations on population sizes
Sonya
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Game Species
Game species are any animals hunted for food or sport and are not normally domesticated.
Heron, Blackcrowned Night or Crabier Batali (Nycticorax nycticorax)
Heron, Boatbilled or Crabier Bec Plat (Cochlearius)
Heron, Yellowcrowned Night or Crabier a Croissant (Nyctanassa violacea)
Rallidae—All birds belonging to the Family Rallidae (Coots, Rails, Waterfowl and their allies)
Ramier or pigeon (all kinds)
Scolopacidae—All birds belonging to the Family Scolopacidae or Snipes and Sandpipers (Snipes, Curlews, Sandpipers, White-wings, Yellow-legs, Godwits, Sanderlings).
Cage birds
These birds may be captured or kept captive by cage:
Chicki-Chong or Bullfinch (Oryzoborous angloensis)
The State of the Environment (SOE) Reports are technical reports that have been conducted under the Environmental Management Authority (EMA) of Trinidad and Tobago. SOE Reports are generally annual and focus on a selected area or aspect of the environment which the EMA has prioritised for attention. Kindly click here to visit the EMA's website or see below for these reports.
