TERRESTRIAL BIODIVERSITY

At first glance one might believe that the Island does not have any vegetation. However, the erosion and meteorization process, along with the guano provided by birds (main source of nitrate and fosfate) and the precipitations that maintain a relatively high humidity level, allow the establishment and development of a series of plants composed by algaes, lichens, moss, some gramineae, arbustive leguminous and ferns. The vegetation uses the guano as a fertilizer and consumed itself  by invertebrates and reptiles that inhabit the island.

Even though the Island really looks like a desolated place. It´s home to a very particular terrestrial fauna which iswell adapted to the rocky sustrate and highly dependant on the little existent vegetation as well as nutrients provided by the sea.

Among these species there are 4 that have an endemic character. Meaning that they can only be found in theis Island.

• The terrestrial crab Johngarthia malpilensis;
• The lizard Anolis agassizi;
• The pointed lizard, Diploglossus millepunctatus;
• The gecko Phyllodactylus transversalis;

Terrestrial crab Johngarthia malpilensis	Male lizard Anolis agassizi	The pointed lizard Diploglossus millepunctatus	Gecko Phyllodactylus transversalis

Female Lizard Anolis agassizi

Bird´s guano is the main nutrient provided for the ecosystem. andthanks to them, the ecologic balance is preserved.. Aditionally, the guano that flows to the sea when mixed with rain represents part of the basis for the production and existence of algae and other phytoplanktonic species around the Island. (Von Humboldt Institute, 1999).

Juvenile Creagrus furcatus	Adult Creagrus furcatus	Brown noddy Anous stolidus

The most abundant bird species is the Nazca Booby Sula granti. In Colombia, this booby nests exclusively in Malpelo and the Island is the shelter of the biggest nesting colony in the World. It is home to aproximately one third to one fourth of the total reproductive population of this species. (Pitman et al., 1995; Pietman y Jehl, 1998; Alvarez, 2000).

Adult Nazca Booby Sula granti	Adult Nazca Booby. Sula granti	Juvenile Nazca Booby. Sula granti

This species usually lays only once a year but whith abundance of food it can nest twice a year and  usually incubates 1 or 2 eggs. Generally only one  chick survives. The couples are highly territorial so they actively defend their nesting territories. Such nests have a circular form and  are built with small stones.

In 1945, Murphy has estimated the population to 25.000 individuals and Pitman in 1995 to 24.034 individuals, that indicates that the population has remained stable for almost 50 years. However, new studies made by the  INVEMAR and  CALIDRIS Association  show that this number could be much bigger, reaching  the 100.000 individuals.