Alien Invasive Species (Animals)Invasive Species Invasive species are threats to habitats, ecosystems and species in Seychelles. Over the last decades, many species have been introduced in Seychelles for many uses. House sparrow (Passer domesticus)
House sparrows have recently been sighted in the PUC power station C, Port area on Mahe. It is not exactly known how they arrived there. It can be prbably via foreign boat vessels. House sparrows have been known to be a pest in agriculture causing economic lost to farmers; house sparrows can be potential disease carrier. Furthermore, they are known to compete with other bird species for food and habitat. There is the potential that should house sparrows become established, they may compete with the endemic Seychelles fody (tok tok). The Conservation Section is currently undertaking the eradication of house sparrows in the port area. Ring Neck Parakeet (Pssitacula krameri)
This introduced bird was first sighted on Mahé in 1974. The parakeet is considered as a pest in agriculture since it feeds on fruits, maize and seeds. It is also a carrier of avian diseases posing a threat to the Seychelles black parrot, which probably is not resistant to these diseases. The ring neck parakeet is a good competitor; there is the potential that it could compete with the black parrot for both food and nesting sites since the two species are of similar sizes. The Conservation Section is taking steps to eradicate the birds from Mahe. Rats (Rattus rattus/Rattus norvegicus)
Rats are efficient predators of eggs, large insects, large reptiles, tortoises, birds and plants. They compete for food sources with herbivores. Norway rats are mainly terrestrial infrequently venturing above three meters up trees and shrubs. Cavity- nesting birds, like the Seychelles Magpie robin is particularly vulnerable. Rats also cause agricultural damage. It has now been found that rats are the vectors of leptopyrosis– a disease that can be deadly to humans and animals if not treated quickly. Some island, namely North Island, Fregate and Bird have conducted rat eradication programme to eliminate rat population. Rats have been successfully eradicated from Fregate and Bird islands. Rodent protocol exists to prevent further invasions. Cats (Felis catus)
Cats have been introduced to islands in an attempt to control rats. Cats on islands of Seychelles have dramatically reduced the range of and have been responsible for countless extinctions of species endemic to islands. It has been suggested that the feral cat was the cause for the extinction of magpie robins on Aride and Alphonse Islands as well as serious declines on Fregate.
On Aldabra, feral cats have been observed to take turtle hatchlings. Cats have been successfully eradicated on Cousine and Fregate islands. Barn owl (Tyto alba affinis)
The Barn owl occurs on most granitic islands in the Seychelles. It has been observed to be predator of fairy terns Gygis alba and other native birds; sunbirds, ground doves. Records show that on Aride, the Barn owl prey on fairy terns, lesser noddies, brown noddies, bridled terns etc…
Barn owls were first introduced from East Africa in 1949 for the biological control of rats in coconut plantations. Ministry of Environment encourages the killing of Barn owl by paying a 30 rupee-bounty (approx. $5). On Aride Island, management control of barn owl is carried out. Birds are shot whenever possible by the Island management. Indian house crow (corvus albus)
This species is thought to have come to Seychelles on ships. Rapid action was taken to eradicate the species since it was a serious agricultural pest; it is also known to take eggs and chicks of birds. A 500-rupee bounty (approx. $100) was introduced to encourage the eradication of house crows. The control programme has been extremely successful leading to complete eradication. Crazy Ant (Anoplolepis gracilipes)
Crazy Ants are invaders of native ecosystems. Crazy ants are efficient predators of most other native insect species as well as other invertebrates. They are aggressive creatures and are now found on most major granitic islands. On Bird island, crazy ants have been seen to attack the chick of sooty terns. The control of these ants is difficult Goats
Goats on Aldabra graze and browse on grass consumed by giant tortoises out-competing the tortoises for food. Furthermore, goats can graze higher than the tortoises taking the lower portions of shrubs which otherwise were accessible to the tortoises. Goats have also been described to be implicated in the rarity of some endemic species. | 
