The Cuban iguana  is a species of lizard of the iguana family. It is the largest of the West Indian rock iguanas, one of the most endangered groups of lizards. This species with red eyes and a thick tail is one of the largest lizards in the Caribbean. The Cuban iguana is mainly _ : 95% of its diet consists of the leaves, flowers and fruits from as many as 30 plant species, including the seaside rock bush and various grasses. However, Cuban iguanas occasionally eat animal matter, and individuals have been watched eating the dead flesh of birds, fish and crabs. The researchers wrote that quite a few people on Isla Magueyes could have caused this incident. The Cuban iguana is living throughout the rocky southern coastal areas of mainland Cuba and its surrounding islands with a wild population growing rapidly on Isla Magueyes, Puerto Rico. It is also found on the Cayman Islands of Little Cayman and Cayman Brac, where a separate subspecies occurs. Females guard their nest sites and often nest in sites half destroyed by Cuban crocodiles. To avoid the attack from them, the Cuban iguana often makes its home within or near prickly-pear cacti . In general the species is decreasing, more quickly on the mainland than on the outlying islands. One of the reasons for their decrease is habitat destruction caused by the over consuming of farm animals, housing development, and the building of tourist resorts  on the beaches where the animals prefer to build their nests. Although the wild population is decreasing, the numbers of iguanas have been sharply increased as a result of captive-breeding and other protection programs. What's the writer's purpose of writing the text?
To give us a brief introduction to the Cuban iguana. To show he is concerned about the Cuban iguana. To explain reasons for the Cuban iguana's decrease. To draw people's attention to an endangered animal