Amphibians and reptiles
Moroccan reptilian fauna, which goes back to the tertiary era, has been through numerous modifications engendered by the topographical and climactic changes of the continents. The hypothesis of a separation between Europe and Africa at the ‘Miocene hags been raised (Bons, 1973). Numerous faunistic exchanges across the Strait of Gibraltar between the two continents have taken place. Other contributions from the Orient came to enrich Moroccan fauna.
It is from the end of the tertiary era that reptilian fauna of the Iberico-African axis began to take on its actual state:
- The arrival of Nordic species, following the glaciers.
- The retreat towards the south of tropical species.
- The ulterior extension of “Ethiopian” elements of fauna.
Our reptilian fauna is the result of numerous changes and vertical and horizontal changes which have permitted the installation of diverse populations. To these exchanges has been added other local factors which have come to mark a fauna considered as the richest and the most diverse of all countries of North Africa.
The importance of this fauna has aroused the interest of many researchers who have constituted a specialized literature and a collection of references (collections of the Scientific Institute, the Museum of Natural History of Paris, British Museum, etc.).
If the quasi totality of our herpetofauna is known, there remain nonetheless some gaps in the case of certain species (inaccessibility of their biotopes, very discreet animals, etc.).
Since the publication of the lists elaborated by Bons (1972) and Mellado and Dakki (1988), the systematic revisions, the discovery of new species and the modifications of the era of distribution of several ‘taxa’ have not ceased to modify the list of Amphibians and Reptiles of Morocco. The list presented here, the most exhaustive so far, makes the state of 103 species.
The Amphibians, a turning point group between aquatic and terrestral Vertebrates, are the first group to have conquered land. Their life remains thus shared between aquatic and terrestral places. Most of the Amphibians of Morocco pass the great part of their existence in water and are excelent biological indicators of water and air pollution.
The Class of Amphibians is presented in our country by 11 species (on 4016 species in the world) belonging to two orders: the Urodele with two species and the Anoures with 9 species (Table 15). The third order, the Apodes (or Gymnophiones), are not represented in Morocco.
The endemic Amphibian species are two in number: The Moroccan Pelobate (Pelobates varaldii), a Mediterranean specie, and the Brongersma Frog (Bufo brongersmai), a Saharan specie. The rare species number three: the tachetee Salamander (Salamandra salamandra) and the childbirthing Frog (Alytes obstetricans), a medio-European species, limit themselves to the most humid and freshest zones of the Rif; the third species, the Moroccan Pelobate, endemic, is found on the North-Atlantic facade.
Appearing less than 320 million years ago, the Reptiles have adapted entirely to terrestral life (anatomical structure of diverse organs, specific constitution of eggs and embryos, etc.). Of discreet nature, silent and of a great agility, these animals can undergo substantial destructions without us realizing it.The Reptiles are represented by 92 species (Table 16) belonging to two Orders: the Chelonians with 3 species (not including 6 marines more or less accidental on our coasts) and the Squamata (or Lepidosaurians) with 89 species, divided between 3 sub-orders: Amphisbenia (3 species); Sauria (61 species) and Ophidia (25 species). The only species of the Order of Crocodilians, the Crocodile of the Nile (Crocodylus niloticus) extinguished from the Moroccan fauna in the 1930’s.
The list of endangered species of Reptiles, at 13, is given in Table 17. The dangers which weigh on these species can be classified into three categories (after the directive guidelines of the PNUE, 1993, slightly modified):
Indirect dangers due to socio-economic factors, of which:
- A1: Demographic pressure;
- A2: Movement of populations;
- A3: Industrialization.
Direct dangers, essentially of anthropic origin:
- B1: Development (transportation, pollution, drainage, mining);
- B2: Tramping (agriculture, destruction/alteration of habitats);
- B3: Exploitation (poaching, direct deduction in advance, national and international commerce, traditional medicine, consummation);
- B4: management of ressources: (inadequate usage of soils, tourism, and abusive human behavior).
Dangers can follow from the absence of knowledge on the species.
Among the 92 species of Reptiles in Morocco (not including the 6 species of marine turtles), 21 are endemic (Table 18); it is the highest endemic rate in all the palearctic western zone! In comparison, Italy, which is at second place, has only 8 endemics. Our immediate neighbors, Algeria and Spain, have 3 endemics each.
The zones richest in endemic ‘taxa’ are, in the order of decreasing importance: The mountainous chains, the plateaus and Atlantic plains, the pre-Saharan and Saharan zones, Souss and the eastern area.
The mountainous massif of the Rif and the Atlas are the most rich in species: 32 species of which 18 are endemic. The wealth of the mountains is explained by the maintenance of Palearctic elements in altitude. The Rif, while on the surface relatively small compared to the rest of the mountainous domain, is particularly rich in endemics. The Atlasic chains (Middle and High Atlas) are characterized by a smaller wealth than the Rif; thus, the risks of a decimation of the reptilian fauna of the Atlas are less important than in other regions of the Kingdom: even with the very active deforestation, there are still beautiful forestral masses, particularly in the Middle Central Atlas, which is a good sanctuary for the fauna.
The Atlantic plains and the plateaus, well explored zones, follow in importance the areas most diversified. They are characterized by a very high endemic rate, which can be explained by the isolation of these plains by the atlasic axis and the great diversity of habitats (forests, steppes, cultures, humid zones, etc.). The dangers which weigh on the reptiles of this region seem thus the greatest: high demographic density, industries, increasing urbanization, destruction of natural habitats, agriculture, intensive animal husbandry, mining exploitation, infrastructures, tourism...
The Pre-Sahara and the Sahara are the most diversified with, for the whole country, the greatest number of species, linked to this particular biome, as well as endangered and rare species, but a small rate of endemics. This high diversity is explained by the mixing between Saharan and Mediterranean elements crossing the Jbel Bani by valleys and by the coastal region, which have succeeded to adapt themselves to these new conditions (Bons, 1959).
The plains of Souss, region of Arganier, are well known by herpetologists and terrariophiles. It offers the smallest diversity, but, in relation to its surface area, seems rich and diversified. It hosts, besides some endemic species, a mix of species of Mediterranean affinities, macaronesian, Saharan and tropical. Thus, the high density in rural areas (46 Hab. /km2) and the diverse deductions made have impoverished the herpetologic fauna, principally the snakes. These ecosystems being faunistically very important, it is imperative to preserve them from now from anthropic effects.
The eastern area, represented by the valley of the Moulouya and the High plateaus, is characterized by difficult life conditions; climates that are dominantly semi-arid, arid and Saharan bioclimactic stage, sometimes strong winds... The vegetation is composed of steppes of alfa and artemesia, tamarisk, jujube tree..These conditions have favorized the installation of species with Saharan and pre-Saharan affinities; other species, Mediterranean and north-African, have also well adapted to these conditions. This biological diversity is characterized by a small rate of endemism and a good presence of species linked to this particular biome.