Wildlife of Sri Lanka

The wildlife of Sri Lanka includes its flora and fauna and their natural habitats. Sri Lanka has one of the highest rates of biological endemism (16% of the fauna and 23% of flowering plants are endemic).

Ecological zones

The mountains and the southwestern part of the country, known as the "wet zone", receive ample rainfall (an annual average of 2500 millimeters). Most of the southeast, east, and northern parts of the country comprise the "dry zone", which receives between 1200 and 1900 mm of rain annually.

Forestry

Faunal diversity

Described species of fauna The most recent update on the Sri Lankan biodiversity was the 6th National Report of the Convention on Biological Diversity. This report provided an updated list of species as of the end 2018. However, in 2019, 54 new species were described: including 26 spiders, (14 cellar spiders, 7 jumping spiders, 4 crab spiders and 1 tarantula), 1 scorpion species, 5 mites and ticks, 14 reptiles (13 day geckos and 1 snake), 1 shrub frog, 1 orchid and 6 lichens. Later in 2021, Professors Devaka Weerakoon and Amila Sumanapala released an updated list of taxa as of the end of 2020.

Vertebrates

Mammals

Sri Lanka is home to roughly 123 species of mammals, 41 of which are threatened (9 critically). 16 of the species are endemic, of which 14 are threatened, including the large sloth bear, the endemic Sri Lanka leopard, the Sri Lankan elephant and the sambar. Bats have the highest amount of species (out of 200 mammalian orders), with 30 species. Sri Lanka's surrounding waters are home to 28 species of Cetaceans.

Reptiles

Sri Lanka currently contains 185 species of reptiles, of which 60 are threatened and 115 are endemic. Most of the reptiles are snakes and the largest two are the mugger crocodile and saltwater crocodile. Flooding has led to increased human-crocodile conflict around the Nilwala River, with crocodiles often becoming trapped as floodwaters recede. Such floods are becoming exacerbated by climate change.

Amphibians

Sri Lanka has one of the richest diversity of amphibians in the world, containing 122 species of amphibians up to January 2019 with many recent discoveries, with 112 endemic species.

Birds

Sri Lanka is home to 227 species of birds (though some past estimates put it as high as 486), 46 of which are threatened (10 critically).

Fish

Sri Lanka contains 93 species of freshwater fish, of which 50 are endemic. 28 species are categorized as threatened by the IUCN. There are 8 species of brackish water fish that also come to freshwater, and 24 introduced exotic fish species.

Insects

Insects belonging to all 32 orders except Grylloblattodea have been recorded from Sri Lanka.

Major insects

Coleoptera, which is the largest order of insects, is the largest in Sri Lanka with 3,033 documented species. Lepidopterans, moths and butterflies, have the second largest number of species in Sri Lanka. 245 butterflies species are recorded, of which 24 are endemic to the island. 1695 species of moths are also found, but the endemism is unknown. Hymenopterans, which includes ants, bees, wasps contribute to the third largest insect order in Sri Lanka. Sri Lanka is home to 181 species of ants that included to 61 genera and 10 subfamilies. One endemic genus Aneuretus is also included to the list. There are about 70,000 species of bees of order Hymenoptera in the world with nearly 450 genera and 7 families. Out of them, Sri Lanka comprises 148 species in 38 genera and 4 families. True flies and mosquitoes belong to the order Diptera, of which there are many in Sri Lanka. There are more than 1,341 dipterans found in the island, which makes it the fourth largest insect order. About 131 species of mosquitoes, in 16 genera, are described. Though they are primary vectors of many human diseases, the majority of mosquitoes in Sri Lanka are harmless to humans and livestock.

Minor insects

The exact species for other orders is still not classified and documented. Walker in 1861, listed 2,007 species belongs to 9 orders and Haly on 1890 identified 1,510 beetle species from Sri Lanka. However, after many publications from many foreign entomologists, two Sri Lankan entomologists, Anura Wijesekara and D. P. Wijesinghe documented 11,144 insect species belongs to 30 orders from Sri Lanka in 2003. Damselflies are categorized in suborder Zygoptera and dragonflies are in suborder Anisoptera. There are 121 species within 13 families in Sri Lanka. 59 species are endemic. Hubbard and co-workers documented 46 species in 8 families of order Ephemeroptera. Henneman in 2002 recorded 69 species in order Orthoptera. He also collected few specimen of order Phasmatodea around central hills. 66 species of order Blattodea are found, but not taxonomic evidences. Few species of the order Mantodea were studied by Henry in 1931. Clear documentation of the species within Dermaptera can be found, which was initiated by Burr (1901) and Brindle (1972). Within the termite infraorder Isoptera, 56 species are recorded. In 1913, Green compiled a concise catalogue for termites in Sri Lanka. Only 4 species of order Embioptera are recorded. In the order Psocoptera, two subfamilies, Epipsocidae and Pseudocaeciliidae have been studied. Information about species of the orders Thysanoptera, Neuroptera, Mecoptera, and Siphonaptera is very thin and more studies are required. Only the family Coniopterygidae of Neuroptera has been studied in 1982. Sri Lanka is known to be home to 794 species of Hemipterans. Detailed work of Sri Lankan hemipterans are recorded in the book Catalogue of Hemiptera of Sri Lanka. Sri Lanka comprises 74 species in 46 genera and 6 families of aphids within the order Hemiptera. 2 endemic aphid species are found on Sri Lanka. Checklists on orders Trichoptera and Strepsiptera exist, but more recent work is needed.

Crustaceans

Freshwater crabs

All 51 species along with 5 genera in the family Gecarcinucidae are endemic to Sri Lanka. 98% of those crabs are IUCN categorized as threatened, endangered or critically endangered.

Isopods

Isopods occur abundantly in the sea, freshwater and land. They typically flattened dorsoventrally and mostly scavengers. Sri Lanka harbors 92 species of isopods of 53 genera in 23 families.

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