The Seychelles Paradise Flycatcher (Terpsiphone corvina) is a small passerine bird endemic to the Seychelles islands in the western Indian Ocean. It is classified as critically endangered on the IUCN Red List with an estimated population of less than 250 mature individuals as of 2018.
The Seychelles Paradise Flycatcher is a striking bird with black plumage on its head, throat, wings, tail, and feet. Adult males have a dramatic long tail streamer that can reach up to 28 cm. The rest of the body and wing coverts are white. Females and juveniles are similarly patterned but lack the long tail feathers.
These birds are found only on the islands of La Digue and Denis in the Seychelles. Their small range and tiny population size have led to the paradise flycatcher being uplisted to critically endangered status in 2018. They face a very high risk of extinction in the wild.
What threats caused the decline?
There are several key factors that have caused the drastic decline of the Seychelles Paradise Flycatcher population over the past few decades:
Habitat loss
– Native forest clearance for agriculture, housing, and development has deprived flycatchers of nesting and foraging grounds.
Invasive species
– Introduced plants have outcompeted native vegetation. Invasive rats, cats, and myna birds predate flycatcher eggs and chicks.
Disease
– Avian malaria transmitted by introduced mosquito species has led to high nestling mortality.
Small population size
– With so few birds left, the species is vulnerable to stochastic threats and inbreeding depression.
Climate change
– Rising sea levels and changing weather patterns threaten coastal mangrove habitats.
Details on each threat:
Habitat loss
The paradise flycatcher’s preferred habitat is native forest containing tall trees for nesting and a dense understory for foraging on insects. However, extensive deforestation has occurred on both La Digue and Denis islands over the past century.
Large areas of land have been cleared for commercial agriculture, especially vanilla, tea, and coconut plantations. Mangrove forests along the coast have been removed for salt pans and urban development as human populations grow.
One study estimated La Digue lost 65% of its natural habitat between 1949 and 2011. Flycatchers now mainly rely on small fragmented forest patches. But these isolated areas may not provide adequate food resources or nest sites.
Invasive species
The Seychelles islands have no native mammalian predators. However, several invasive species introduced after human colonization pose significant threats to the paradise flycatcher:
- – Black rats prey on eggs and nestlings.
- – Feral cats hunt adult flycatchers.
- – Introduced myna birds compete for nest cavities.
Invasive plant species such as cinnamon, guava, and chinaberry have also displaced native broadleaf trees and caused a decline of food plants.
Disease
Avian malaria is a mosquito-borne disease that affects forest birds. The Seychelles paradise flycatcher evolved without this disease and has little natural immunity.
Malaria was likely introduced when colonists brought non-native bird species to the islands. Invasive mosquito species such as Culex are now vectors for the disease.
Studies have found high avian malaria infection rates in flycatcher nestlings, often exceeding 50%. This disease factor alone may account for up to 26% of annual nest failures.
Small population size
The Seychelles paradise flycatcher has a tiny global population estimated at only 170-250 mature individuals as of 2018. Such a small population is at high risk of extinction due to:
- – Environmental disasters such as storms or disease outbreaks
- – Loss of genetic diversity and inbreeding depression
- – Random demographic fluctuations
Small fragmented subpopulations on Denis and La Digue islands are also more vulnerable compared to one large population. Isolation restricts genetic exchange between islands.
Climate change
Climate models predict sea level rise of 0.5-1 meter by 2100 in the Indian Ocean. Low elevation islands like La Digue and Denis are susceptible to coastal erosion and flooding.
This could destroy mangrove habitats used by paradise flycatchers for foraging and nesting. Climate change may also increase the spread of mosquito-borne diseases and the severity of storms that damage native forests.
Conservation efforts
The dire status of the paradise flycatcher has prompted research and conservation actions to protect the species including:
- – Habitat restoration programs to replant native vegetation.
- – Control and eradication efforts targeting invasive predators.
- – Anti-malaria treatments to improve nestling survival.
- – Monitoring flycatcher populations and studying threats.
- – Raising local community awareness to promote conservation.
In 2015, the Seychelles government designated several key flycatcher habitats as Important Bird Areas. However, habitat loss and degradation continue in unprotected areas.
Captive breeding has not yet been attempted for this endangered species due to risks such as loss of wild behaviors. Safeguarding remaining flycatcher habitat is the most urgent priority for its survival.
Conclusion
The Seychelles Paradise Flycatcher is Critically Endangered primarily due to extensive habitat loss on its tiny island range compounded by invasive species and disease. Its severely small population faces high risks of extinction.
Ongoing conservation projects aim to protect remaining native forests, control predators, and boost nesting success. However, these efforts must be scaled up to match the high severity of threats. Saving the paradise flycatcher requires a coordinated strategy between government, scientists, and local communities before it is too late.
