Terrestrial Species Diversity

The fauna of the island of S. Tomé is really remarkable and even more remarkable is the difference that makes its sister, Príncipe. In Principe the animals that are found are mostly from the mainland, while in S. Tome there is a special form with many species that I believe are exclusive to the island. The distance between the two islands is only 90 miles but the submarine cable launched is 120 miles due to the undulations of the land on the bottom of the sea. With regard to Atlantis, are not the islands of the Gulf of Guinea and even the Canary Islands, Cape Verde, St. Helena, Assumpção, etc., remnants of this great continent?

Francisco Newton, letter from São Tomé Island 23 January 1887

 

The biodiversity (all life forms) of São Tomé and Príncipe is remarkable. The islands show an important richness of flora and fauna species, especially considering their relatively small size. The interior flora and fauna of the islands show an important proportion of species that are not found in any other part of the world, that is, endemic to the islands.

FLORA

The first surveys on the flora of São Tomé and Príncipe date back to the colonial period, in relation to which the studies carried out by Welwitshi, Barter and Mann, who visited the island of São Tomé, respectively, in 1853, 1858 and 1861, stand out above all. These studies led to the discovery of many previously unknown species. The first investigations, quite complete and coherent, carried out on the vegetation of São Tomé and Príncipe, were carried out in 1932 and 1933, by the researcher Exell (1944, 1956).

It is estimated that in the current state of knowledge of the flora and vegetation in the country, the estimated number of floristic species existing in the archipelago is around 1,200, of which around 900 are indigenous (including 148 endemic species) and around 300 are introduced (sub-spontaneous or cultivated). In total, the plant biodiversity of spermatophytes in São Tomé is estimated at approximately 700 species.

The 5th CBD Report on the Status of Biodiversity (2014) the most representative families, belonging to the terrestrial angiosperm group, are: the Rubiaceae (27 species, of which 23 – 85% – are endemic), the Orchidaceae (22 endemic species), the Euphorbiaceae (11 species, seven of which are endemic – 64%), the Melastomataceae (8 endemic species out of a total of 17 species, i.e. 47% of endemism) and the Begoniaceae (6 endemic species out of a total of 11, i.e. 55% endemism). Some of these groups are especially rich, such as orchids, which include around 135 species. This same report informs that a total of 148 plant species (14% of the national flora) are endemic to the country, 50 of which are present in Príncipe and 123 in São Tomé (of which 25 are common to both islands). It is estimated that, according to the IUCN code, 14.9% of endemic species of São Tomé and Príncipe have the status of vulnerable (VU), 12.2% are near threatened (NT) and 7.4% have a wide area of distribution, having a status of Least Concern (LC).

 

The national flora also includes more than 100 pteridophytes (ferns and similar) and about 800 species of seed plants (spermatophytes). Pteridophytes are distributed in 28 different families and have 9 endemic species.

 Description

Príncipe

São Tomé

Endemic species of a single island

28

90

Endemics shared between islands

30

32

Total endemisms

58

122

Indigenous species

394

842

Endemism rate (2 islands)

14.7

14.5

Endemism rate (strict)

7.6

3.8

  • Fauna

In general terms, the national heritage of vertebrate animals is well known and is characterized by inland, marine and transitional species. The faunal biodiversity of the interior (see Table 1) is especially rich in birds, reptiles, amphibians and invertebrates. In general, it comprises more than 10 species of small mammals, 49 species of birds, 16 of reptiles, 8 of amphibians, as well as other Classes with considerable representation in São Tomé and Príncipe.

  •  Avifauna

With 1,001 km², São Tomé and Príncipe sustains a birdlife represented by 29 endemic bird species (São Tomé with 9 endemic species, Príncipe with 10 endemic species and 10 more for both islands). This is how, since 1990, it has been recognized that the avifauna of São Tomé and Príncipe constitutes 25% of the endemism of the 218 Endemic Bird Regions (EBA) worldwide and, very recently, the two islands were included in the list of Important Regions of Birds (IBA) of Africa, as well as the second, in terms of bird conservation priority, among 75 African forests (World Bank, 1993), housing a remarkable natural heritage.

 

In coastal regions, the avifauna is constituted fundamentally by the birds that mainly populate the small islets and uninhabited coastal zones. The main species that nest in colonies are the Phaeton lepturus (Coconzucu), Sula leucogaster, Sula dactylatra, Anous stolidus, Anous minutus, … Coturnix delegorguei) and the African quail (Crecopsis egregia). Currently these bird species have the status of threatened, specifically of Critically Endangered species (CR), according to the IUCN. Studies carried out prove that the Tinhosas Islands are the main cradle of seabirds in the Gulf of Guinea. They are home to some of the main breeding colonies of seabirds on the coast of West Africa, with tens of thousands of breeding pairs. This importance led to the recognition of these Islands as sites of international relevance under the RAMSAR convention.

  • Repriles

According to data obtained from the publication “Conservation of Forest Ecosystems in the Democratic Republic of São Tomé and Príncipe (Jones et al. 1991), there are fourteen species of reptiles in São Tomé, four of which are common to both islands.

 

On the island of São Tomé there are, for example, the gecko, or gecko (Hemidactylus greeffii), the lizard (Afroablepharus africanus), the burrowing snake (Rhinotyphlops newtoni), the black snake (Naja melanoleuca) and the jita (Boaedon lineatus ). For the island of Principe there are, for example, the Lizard without legs (Feyinia polylepis), the Principe's jester snake (Typlops elegans), the Príncipe's green snake (Hapsidophrys principis) and the golden gecko (Hemidactylus principensi) . The jita (Boaedon lineatus) and the gecko Lygodactylus thomensis are endemic species to the islands of São Tomé and Príncipe.

 

The order of the Testudines is represented by the bencú of the marshes (Pelusio castaneus) and the bencú of the forest (Pelusio gabonensis). Bencus are an increasingly rare species in our ecosystems, and the trend towards a decrease in numbers is notorious. In general, the perception is that the bencú, or African tortoise, is decreasing, however there is a lack of information on the number of populations, the status and distribution of both species, which makes it necessary to carry out studies for the knowledge of the taxonomy, reproductive biology and ecology of the two species.

  • Batrachians and Caecilians

The Class Amphibia santomense is represented by four Families of the Order Anura and one Family of the Order Gymnophiona, in a total of seven species, of which six are identified in São Tomé, two in Príncipe and two in Ilhéu das Rolas. One species is common to the three islands (Phrynobatrachus dispar), one species is endemic to São Tomé and Ilhéu das Rolas (Schistometopum thomense), two species are restricted to São Tomé (Hyperolius molleri and Hyperolius thomensis) and one species is endemic to the island of Prince (Leptopelis palmatus).

The islands' six batrachian species (frogs and rainnets) and one of the two caecilians (Schistometopum thomense) are endemic. Principe has two unique species, including the recently described raineta Phrynobatrachus leveleve, and São Tomé has four species, including the (Schistometopum thomense), incorrectly, but for obvious reason, nicknamed in the vernacular as 'São Tomé's silly snake '.

The species Schistometopum thomense (from the order Gymnophiona), with the vernacular designation of São Tomé bobo snake, although not specific to aquatic environments, frequents humid environments, building galleries like earthworms (cormichas).

In S. Tomé, the following endemic species can also be found: the rainettes: Hyperolius molleri and Hyperolius thomensis and the frog of the species Ptychadena newtoni. On the island of Príncipe, you can also find the tree frog, belonging to the species Leptopelis palmatus, and the frog, Phrynobatrachus dispar.

  • Entomological Fauna

Regarding the entomological fauna, in the archipelago there are about 89 species of butterflies; São Tomé with 47 species and Príncipe with 42 species, with an endemism rate of 38% and 21%, respectively. Bees of the genus Apis are melliferous and play a very important role in pollination (fertilization of flowering plants), thus contributing to the conservation of forest areas. The insect-plant co-evolutionary relationship can be harnessed in beekeeping. However, the practice of beekeeping in the country is not carried out with due procedures; beekeepers kill bees to extract their honey instead of just fumigating them. In addition to these species, centipedes (class Diplopoda) are represented by Globanus integer and Blobunus marginescaber (Milipeias de S. Tomé), which have protected status.

  • Land Mammals

The islands of São Tomé and Príncipe are very rich in endemic or indigenous species of mammals, mainly due to their distance from the mainland. However, we can find the São Tomé shrew (Crocidura thomensis), which is endemic to the island, while the Príncipe shrew (Crocidura poensis) is an endemic subspecies of the island. Among the bats in São Tomé there are two species and three subspecies endemic to the island, while Príncipe has one species and one subspecies endemic. In addition to these, we also found six other species of bats – Myonycteris brachycephala, Hipposiderus thomensis, Miniopterus minor and Rousettus aegyptiacus, and continental forms, namely Eidolon helvun and Hipposideros ruber. As far as introduced terrestrial mammals are concerned, monkeys (Cercophitecus mona), wild pigs (Sus domesticus), parrots (Civettictis civetta), water bream (Mustela nivalis), as well as Mus musculus rats, Rattus rattus and Rattus norvegicus can be found. 

  • Freshwater fish and crustaceans

Different species of fish and crustaceans live in fresh and slightly brackish waters, including, among other fish, Eleotris vittata (charoco), Pomadasys jubelini (Rocandor or bream) and Oreochromis niloticus (tilapia or papê).

With regard to crustaceans, in the rivers and streams of the country, the deep Izé, Má bobô and Má plamina and the white Izé can be found. Another shrimp that is also seen in rivers and streams in São Tomé and Príncipe is the Manglolô, whose scientific name is Sicydium bustamantei. In addition to this species of crustaceans, crabs characteristic of rivers, riverbanks and land (cardisoma armatum) can be observed.

Currently, these species are endangered due to the washing of containers and mosquito nets in rivers, streams and streams, containing waste of sanitary products against the mosquito vector of malaria, which is the basis for the destruction of the fauna of rivers and streams. No less important is the incorrect use of chemical products in agriculture, such as fertilizers, herbicides and insecticides, whose impacts on biodiversity are disastrous.

GROUP OF ORGANISM

ISLANDS

N.º OF SPECIES

ENDEMISMOS (%)

Mammals (except bats)

São Tomé

10

30

Príncipe

5

20

Mammals (bats)

São Tomé

9

55

Príncipe

4

50

Birds

São Tomé

49

57

Príncipe

35

54

Reptiles

Total do país

16

44

Amphibians

São Tomé

6

100

Príncipe

3

100

Insects (Butterflies)

São Tomé

47

38

Príncipe

42

21

Molluscs

São Tomé

39

77

Príncipe

32

78

Higher plants

Both Islands

895

15

Total species (Terrestrial Biodiversity)

 

1192

 

São Tomé, 26 de Julho de 2023

Total of Species

0
Terrestrial Biodiversity