Bermuda's ecology has an abundance of unique flora and fauna due to the island's isolation from the mainland of North America. The wide range of endemic species and the islands form a distinct ecoregion, the Bermuda subtropical conifer forests. The variety of species found both on land and in the waters surrounding Bermuda have varying positive and negative impacts on the ecosystem of the island, depending on the species. There are varying biotic and abiotic factors that have threatened and continue to threaten the island's ecology. There are, however, also means of conservation that can be used to mitigate these threats.
Located 900 km off the American East Coast, Bermuda is a crescent-shaped chain of 184 islands and islets that were once the rim of a volcano. The islands are slightly hilly rather than having steep cliffs, with the highest point being 79m. The coast has many bays and inlets, with sandy beaches especially on the south coasts. Bermuda has a semi-tropical climate, warmed by the Gulf Stream current. Bermuda is very densely populated. Twenty of the islands are inhabited.
Wildlife that could fly to the island or were carried there by winds and currents formed the species. There are no native mammals other than bats, and only two reptiles, but large numbers of birds, plants, and insects. [1] [2] Once on the island, organisms had to adapt to local conditions, such as the humid climate, lack of fresh water, frequent storms, and salt spray. The area of the islands shrank as water levels rose at the end of the Pleistocene epoch, and fewer species were able to survive in the reduced land-area. Nearly 8,000 different species of flora and fauna are known from the islands of Bermuda. The number is likely to be considerably higher if all microorganisms, cave-dwellers and deep-sea species were counted. [3]
Today the variety of species on Bermuda has been greatly increased by introductions, both deliberate and accidental. Many of these introduced species have posed a threat to the native flora and fauna because of competition and interference with habitat.
Over 1000 species of vascular plant are found on the islands, the majority of which are introduced. Of the 165 native species, 17 are endemic. Forest cover is around 20% of the total land area, equivalent to 1,000 hectares (ha) of forest in 2020, which was unchanged from 1990. [4] [5]
At the time of the first human settlement by shipwrecked English sailors in 1593, Bermuda was dominated by forests of Bermuda cedar ( Juniperus bermudiana ) [6] with mangrove swamps on the coast. More deliberate settlement began after 1609, and colonists began clearing forests to use for building and shipmaking, and to develop agricultural cultivation. By the 1830s, the demands of the shipbuilding industry had denuded the forests, but these recovered in many areas.
In the 1940s the cedar forests were devastated by introduced scale insects, which killed roughly 8 million trees. Replanting using resistant trees has taken place since then, but the area covered by cedar is only 10% of what it used to be. Another important component of the original forest was Bermuda palmetto ( Sabal bermudana ), a small palm tree. It now grows in a few small patches, notably at Paget Marsh. Other trees and shrubs include Bermuda olivewood ( Cassine laneana ) and Bermuda snowberry ( Chiococca alba ). The climate allows for the growth of other palms such as royal palm ( Roystonea spp.) and coconut palm ( Cocos nucifera ), although the lack of very warm temperatures does not usually allow coconuts to fruit properly. Bermuda is the farthest north location in the Northern Hemisphere where coconut palms will grow naturally. [7]
Remnant patches of mangrove swamp can be found around the coast and at some inland sites, including Hungry Bay Nature Reserve and Mangrove Lake, Bermuda. These were important for moderating the effects of storms and providing transition habitats. Here black mangrove ( Avicennia germinans ) and red mangrove ( Rhizophora mangle ) are the northernmost mangroves in the Atlantic. The inland swamps are particularly interesting as mangroves thrive in salty water; in this case, the saltwater arrives through underground channels rather than the usual tidal wash of coastal mangrove swamps. Areas of peat marsh include Devonshire, Pembroke, and Paget marshes.
Bermuda has four endemic ferns: [8] Bermuda maidenhair fern ( Adiantum bellum ), Bermuda Shield Fern ( Thelypteris bermudiana ), Bermuda cave fern ( Ctenitis sloanei ) and Governor Laffan's fern ( Diplazium laffanianum ). The latter is extinct in the wild but is grown at Bermuda Botanical Gardens. The endemic flora of the island also include two mosses, ten lichens and forty fungi.
Among the many introduced species are the Casuarina ( Casuarina equisetifolia ) and Suriname cherry ( Eugenia uniflora ).
Bermudiana ( Sisyrinchium bermudiana ) Darrell's fleabane ( Erigeron darrellianus ) Bermuda campylopus (moss) ( Campylopus bermudianus ) Bermuda bean ( Phaseolus lignosus ) Bermuda spike rush ( Eleocharis bermudiana ) Bermuda trichostomum (moss) ( Trichostomum bermudanum ) Governor Laffan's fern ( Diplazium laffanianum )
Bermuda has no native amphibians. A species of toad, cane toad (Rhinella marina), and two species of frog, Antilles coqui (Eleutherodactylus johnstonei), and Eleutherodactylus gossei were introduced by humans through the transportation of orchids to the island prior to the 1900s, and subsequently became naturalized. R. marina and E. johnstonei are common, but E. gossei is thought to have been recently extirpated. They are nocturnal and can often be heard at night in Bermuda. Their songs are most prevalent from April until November. [9]
Four species of lizard and two species of turtle comprise Bermuda's non-marine reptilian fauna. Of the lizards, the Bermuda rock lizard (Plestiodon longirostris), also known as the rock lizard or Bermuda skink, is the only endemic species. [2] Once very common, the Bermuda skink is critically endangered. The Jamaican anole ( Anolis grahami ) was deliberately introduced in 1905 from Jamaica and is now by far the most common lizard in Bermuda. The Leach's anole (Anolis leachii) was accidentally introduced from Antigua about 1940 and is now common. The Barbados anole (Anolis extremus) was accidentally introduced about 1940 and is rarely seen. The diamondback terrapin (Malaclemys terrapin) is native to Bermuda. [1] The red-eared slider (Trachemys scripta elegans) was introduced as a pet, but has subsequently become invasive. [10]
All mammals in Bermuda are human introductions, except for four species of migratory North American bats of the genus Lasiurus : the hoary bat, eastern red bat, Seminole bat and silver-haired bat. Early accounts refer to wild or feral hogs, descendants of pigs left by the Spanish and Portuguese as feedstock for ships stopping at the islands for supplies. The house mouse, brown rat and black rat were accidentally introduced soon after the settlement of Bermuda, and feral cats have become common as another introduced species.
Over 360 species of bird have been recorded on Bermuda. The majority of these are migrants or vagrants from North America or elsewhere. Only 24 species breed; 13 of these are thought to be native.
One endemic species is the Bermuda petrel or cahow (Pterodroma cahow), which was thought to have been extinct since the 1620s. Its ground-nesting habitats had been severely disrupted by introduced species and colonists had killed the birds for food. In 1951, researchers discovered 18 breeding pairs, and started a recovery program to preserve and protect the species.
An endemic subspecies is the Bermuda white-eyed vireo or chick-of-the-village (Vireo griseus bermudianus). The national bird of Bermuda is the white-tailed tropicbird or longtail, which is a summer migrant to Bermuda, its most northerly breeding site in the world. Other native birds include the eastern bluebird, grey catbird and perhaps the common ground dove. The common moorhen is the most common native waterbird; very small numbers of American coot and pied-billed grebe are breeding. Small numbers of common tern nest around the coast. The barn owl and mourning dove colonized the island during the 20th century, and the green heron has recently begun to breed.
Of the introduced birds, the European starling, house sparrow, great kiskadee, rock dove, American crow and chicken [11] are all very numerous and considered to be pests. Other introduced species include the mallard, northern cardinal, European goldfinch and small numbers of orange-cheeked and common waxbills. The yellow-crowned night heron was introduced in the 1970s to replace the extinct native heron.
Fossil remains of a variety of species have been found on the island, including a crane, an owl and the short-tailed albatross. Some of these became extinct as the islands' land-mass shrank by nine tenths after the Last Glacial Maximum, while others were exterminated by early settlers. The Bermuda petrel was thought to be extinct until its rediscovery in 1951.
Among the many non-breeding migrants are a variety of shorebirds, herons and ducks. In spring many shearwaters can be seen of the South Shore. Over 30 species of New World warbler are seen each year, with the yellow-rumped warbler being the most abundant. The arrival of many species is dependent on weather conditions; low-pressure systems moving across from North America often bring many birds to the islands. Among the rare visitors recorded are the Siberian flycatcher from Asia and the fork-tailed flycatcher and tropical kingbird from South America.
Lawrence Ogilvie, Bermuda's agricultural scientist 1923 to 1928 identified 395 Bermuda insects and wrote the Department of Agriculture's 52-page book The Insects of Bermuda, including Aphis Ogilviei that he discovered.
There are 4 ant species that are found in Bermuda. The African big-headed ant (Pheidole megacephala) and Argentine ant (Linepithema humile) are both invasive species to Bermuda. The African ant was first recorded on the island in 1889, and the Argentine ant arrived in Bermuda the 1940s. These two ants battle for territory and control over the island. Furthermore, there is the Bermuda ant (Odontomachus insularis), which is indigenous to the island. This ant was initially presumed to be extinct, however, they were re-discovered living in July of 2002. Carpenter ants (Carpenter ant) are also found in Bermuda. [12]
More than 1100 kinds of insects and spiders are found on Bermuda, including 41 endemic insects and a possibly endemic spider. Eighteen species of butterfly have been seen; about six of these breed on the islands, including the large monarch and the very common Bermuda buckeye (Junonia coenia bergi). More than 200 moths have been recorded; one of the most conspicuous is Pseudosphinx tetrio , which can reach 9 cm (3.5 in) in length.
Bermuda has lost a number of its endemic invertebrates, including the Bermuda cicada ( Neotibicen bermudianus), which became extinct when the cedar forests disappeared. Some species feared extinct have been rediscovered, including a Bermuda land snail ( Poecilozonties circumfirmatus ) and the Bermuda ant ( Odontomachus insularis ).
Bermuda lies on the western edge of the Sargasso Sea, an area with high salinity, high temperature and few currents. Large quantities of seaweed of the genus Sargassum are present and there are high concentrations of plankton, but the area is less attractive to commercial fish species and seabirds.
Greater diversity is present in the coral reefs which surround the island.
A variety of whales, dolphins and porpoises have been recorded in the waters around Bermuda. The most common of these is the humpback whale, which passes the islands in April and May during its northward migration.
There are many fish species prevalent in Bermuda's waters, such as the Barracuda, Bermuda chub, Bluestriped grunt, Hogfish, Longspine squirrelfish, various types of Parrotfish, Smooth trunkfish, and Slippery dick, to name a few. [9]
There are various types of sea squirts, such as the Black Sea Squirt (Black Sea Squirt), the Purple Sea Squirt (Clavelina picta), the Orange Sea Squirt (Ecteinascidia turbinata), and the Lacy Sea Squirt. [9]
There are various types of crabs in Bermuda. There are, Sally Lightfoot crabs (Grapsus grapsus), Decorator crabs (Decorator crab), Swimming crabs (Portunidae), Spider crabs (Majoidea), and Verrill's Hermit crab (Calcinus verrillii). Great Land crabs (Cardisoma guanhumi) are hard to find in Bermuda, however they are there. Finally, there is the crab native, but not exclusive to, Bermuda, which are the Bermuda land crabs (Gecarcinus lateralis). [9]
Bermuda was the first place in the Americas to pass conservation laws, protecting the Bermuda petrel in 1616 and the Bermuda cedar in 1622. It has a well-organised network of protected areas including Spittal Pond, marshes in Paget and Devonshire and Pembroke Parishes, Warwick Pond and the hills above Castle Harbour.
Only small areas of natural forest remain today; much was cleared since colonisation began in the 17th century, and recovered forest was lost in the 1940s due to insect infestation. The Bermuda petrel and Bermuda skink are highly endangered, and Bermuda cedar, Bermuda palmetto and Bermuda olivewood are all listed as threatened species. Some wild plants, including a spike rush, have disappeared. Introduced plants and animals have had adverse effects on the wildlife of the islands. The thriving tourist industry creates its own challenges to preserve the wildlife and habitat that attract visitors.
Parrotfish are crucial to the coral reefs of Bermuda. Overfishing has caused issues for parrotfish that live in the coastal waters of other islands, such as the U.S. Virgin Islands. Looking at these instances in other habitats can help conservationists prevent the parrotfish population in Bermuda from experiencing decline as well. [13]
Bird species such as the white-tailed tropicbird are affected largely by hurricanes, as they bring immediate harm to individuals as well as destroying their nests, which makes reproducing impossible. Invasive species are also a big problem for the white-tailed tropicbird, as other bird species have been known to use similar nesting sites to the white-tailed tropicbird. Specifically, the rock pigeon often builds its nests within crevices around the island, including on rocky shorelines and cracks in Bermuda's tall cliffs. This is also where the Bermuda longtail makes its nest, so the competition created by the invasive rock pigeon makes reproduction harder for the longtail. [12]
Bermuda is an overseas territory of the United Kingdom in the North Atlantic Ocean. Located off the east coast of the United States, it is situated around 1,770 km (1,100 mi) northeast of Miami, Florida, and 1,350 km (840 mi) south of Halifax, Nova Scotia, west of Portugal, northwest of Brazil, 1,759 km (1,093 mi) north of Havana, Cuba and north-northeast of San Juan, Puerto Rico. The nearest landmass is Cape Hatteras, North Carolina, about 1,030 km (640 mi) west-northwest, followed by Cape Sable Island, Nova Scotia, Canada 1,236 km northward. Although commonly referred to in the singular, the territory consists of approximately 138 islands, with a total area of 57 km2 (22 sq mi).
The wildlife of Costa Rica comprises all naturally occurring animals, fungi and plants that reside in this Central American country. Costa Rica supports an enormous variety of wildlife, due in large part to its geographic position between North and South America, its neotropical climate, and its wide variety of habitats. Costa Rica is home to more than 500,000 species, which represent nearly 5% of the species estimated worldwide, making Costa Rica one of the 20 countries with the highest biodiversity in the world. Of these 500,000 species, a little more than 300,000 are insects.
The Bermuda petrel is a gadfly petrel. Commonly known in Bermuda as the cahow, a name derived from its eerie cries, this nocturnal ground-nesting seabird is the national bird of Bermuda and can be found pictured on Bermudian currency. The Bermuda petrel is the second rarest seabird on the planet. They have medium-sized bodies and long wings, a greyish-black crown and collar, dark grey upper-wings and tail, white upper-tail coverts and white under-wings edged with black, and the underparts are completely white.
Cousin Island is a small granitic island of the Seychelles, lying 2 km (1.2 mi) west of Praslin. It is a nature reserve protected under Seychelles law as a Special Reserve. It is managed by Nature Seychelles, a national nonprofit organization and Partner of BirdLife International, by which it has been identified as an Important Bird Area.
Spittal Pond Nature Reserve is the largest wildlife sanctuary in Bermuda, located close to the Atlantic coast of Smith's Parish. Surrounding the third largest pond in Bermuda, Spittal Pond, it covers an area of 60 acres (24 ha). It is one of 13 parks or reserves managed by the Bermuda Department of Conservation Services which protects and conserves environmentally critical areas and habitats. The pond reserve, a wetland site, is one of the seven Ramsar Sites in Bermuda, which was approved on 10 May 1999 for the criteria of its unique characteristics such as its lagoon which is permanently brackish, ecology featuring wet grassland and mangrove forests, seasonal shorebirds, other ver run waterbirds and European eels. It is also home to many types of species mostly including birds.
Juniperus bermudiana is a species of juniper endemic to Bermuda. This species is most commonly known as Bermuda cedar, but is also referred to as Bermuda juniper. Historically, this tree formed woodland that covered much of Bermuda. Settlers cleared part of the forest and the tree was used for many purposes including building construction and was especially prized for shipbuilding. Scale insects introduced during the Second World War construction of United States airbases in Bermuda devastated the forests, killing over 99% of the species. Since then, the salt tolerant Casuarina equisetifolia has been planted as a replacement species, and a small number of Bermuda cedars have been found to be resistant to the scale insects. Populations of certain endemic birds which had co-evolved with the tree have plummeted as a result of its demise, while endemic cigalas and solitary bees were driven to extinction.
The fauna of Puerto Rico is similar to other island archipelago faunas, with high endemism, and low, skewed taxonomic diversity. Bats are the only extant native terrestrial mammals in Puerto Rico. All other terrestrial mammals in the area were introduced by humans, and include species such as cats, goats, sheep, the small Indian mongoose, and escaped monkeys. Marine mammals include dolphins, manatees, and whales. Of the 349 bird species, about 120 breed in the archipelago, and 47.5% are accidental or rare.
Saint Helena, Ascension Island and Tristan da Cunha, as well the other uninhabited islands nearby, are a haven for wildlife in the middle of the Atlantic Ocean. The islands are or were home to much endemic flora and fauna, especially invertebrates, and many endemic fish species are found in the reef ecosystems off the islands. The islands have been identified by BirdLife International as Important Bird Areas for both their endemic landbirds and breeding seabirds.
The fauna of the United States of America is all the animals living in the Continental United States and its surrounding seas and islands, the Hawaiian Archipelago, Alaska in the Arctic, and several island-territories in the Pacific and in the Caribbean. The U.S. has many endemic species found nowhere else on Earth. With most of the North American continent, the U.S. lies in the Nearctic, Neotropic, and Oceanic faunistic realms, and shares a great deal of its flora and fauna with the rest of the American supercontinent.
The fauna of Barbados comprises all the animal species inhabiting the island of Barbados and its surrounding waters. Barbados has more biodiversity than the other Antilles. Human activities are responsible for the change in the composition of the fauna, in particular, the replacement of native species. Species that are able to adapt to human presence have survived.
The wildlife of the Maldives includes the flora and fauna of the islands, reefs, and the surrounding ocean. Recent scientific studies suggest that the fauna varies greatly between atolls following a north–south gradient, but important differences between neighbouring atolls were also found, which may be linked to differences in fishing pressure – including poaching.
The wildlife of Japan includes its flora, fauna, and natural habitats. The islands of Japan stretch a long distance from north to south and cover a wide range of climatic zones. This results in a high diversity of wildlife despite Japan's isolation from the mainland of Asia. In the north of the country, north of Blakiston's Line, there are many subarctic species which have colonized Japan from the north. In the south there are south-east Asian species, typical of tropical regions. Between these areas lies the temperate zone which shares many species with China and Korea. Japan also has many endemic species that are found nowhere else in the world, making it home to many endangered/rare species.
The wildlife of Seychelles comprises the flora and fauna of the Seychelles islands off the eastern coast of Africa in the western Indian Ocean.
Christmas Island National Park is a national park occupying most of Christmas Island, an Australian territory in the Indian Ocean southwest of Indonesia. The park is home to many species of animal and plant life, including the eponymous red crab, whose annual migration sees around 100 million crabs move to the sea to spawn. Christmas Island is the only nesting place for the endangered Abbott's booby and critically endangered Christmas Island frigatebird, and the wide range of other endemic species makes the island of significant interest to the scientific community.
The Ascension scrub and grasslands ecoregion covers the dormant volcano, Ascension Island in the Atlantic Ocean. As well as shrubs and grasses wildlife on the island includes a range of unique flora and fauna. In particular the surrounding islets are important havens for many seabirds. However the seabird populations on Ascension Island itself have been severely affected by introduced species, especially cats, which were the subject of an eradication campaign between 2002 and 2006.
Paget Marsh Nature Reserve, also known as Paget Marsh, is an unspoiled marsh, forest, and nature reserve in central Bermuda. It is located next to St. Paul's Church along Middle Road in Paget Parish, to the south of Hamilton Harbour. The 25 acres (10 ha) official reserve is protected by the Bermuda National Trust and Bermuda Audubon Society. It is also a Ramsar wetland of international importance.
The fauna of the United States Virgin Islands consists of 144 species of birds, 22 species of mammals, 302 species of fish and 7 species of amphibians. The animals include numerous native species of tropical birds, fish, and land reptiles as well as sea mammals. The only native land mammals are six species of native bats: the greater bulldog bat, Antillean fruit-eating bat, red fruit bat, Brazilian free-tailed bat, velvety free-tailed bat and the Jamaican fruit bat. Some of the nonnative land mammals roaming the islands are the white-tailed deer, small Asian mongoose, goats, feral donkeys, rats, mice, sheep, hogs, dogs and cats.
The wildlife of Christmas Island is composed of the flora and fauna of this isolated island in the tropical Indian Ocean. Christmas Island is the summit plateau of an underwater volcano. It is mostly clad in tropical rainforest and has karst, cliffs, wetlands, coasts and sea. It is a small island with a land area of 135 km2 (52 sq mi), 63% of which has been declared a National park. Most of the rainforest remains intact and supports a large range of endemic species of animals and plants.
The Jamaican moist forests is a tropical and subtropical moist broadleaf forests ecoregion in Jamaica.