Galapagos Land Iguanas

This work was done in collaboration with Stephen Schnitzer

In the Galapagos Islands, there are three distinct types of Galapagos Land Iguanas: Conolophus subcristatus, Conolophus pallidus, and the extremely rare Pink Land Iguana (Conolophus marthae). 

Galapagos Land Iguana, Wildscreen Arkive
Conolophus subcristatus

Santa Fe Land Iguana, Wildscreen Arkive 
Conolophus pallidus

 

Pink Land Iguana, Maggie's Science Section

Conolophus marthae 

While all of the Land Iguanas are thought to have a common ancestor, it is believed the  Pink Iguana changed millions of years ago to become an entirely different species. The Land Iguanas live on the following Galapagos islands: Fernandina, Isabela, Santa Cruz, North Seymour, Baltra, and South Plaza. These wondrous, cold-blooded creatures can grow to a stunning three to five feet, weighing up to twenty-five to thirty pounds and can live up to an fifty to sixty years of age. The Land Iguana has a very interesting and distinct appearance, the color of the land iguana varies depending on which island of the Galapagos it lives on. In the western part of the islands, there are two distinct forms, the Pink Land Iguana (Conolophus marthae) and the Santa Fe Land Iguana (Conolophus pallidus). The Pink Land Iguana has rose colored scales and blackish stripes, while the Santa Fe Land Iguanas are yellowish in color. The Galapagos Land Iguana (Conolophus subcristatus) is the main species and ives on six different islands. These Land Iguanas are similar in color to the iguanas found on Santa Fe. They have a very intriguing diet, most land iguanas are indeed herbivores but some may become carnivorous in certain situations consuming insects, centipedes, and carrion. Due to lack of freshwater resources on the islands, 80% of the Land Iguana's diet comes from the prickly pear cactus which contains an abundance of fresh water. Some birds have a symbiotic relationship with the land guana. The birds eat ticks and parasites off of the iguana keeping the iguana clean, while giving food to the bird. Sadly due to human and nonnative forces, these magnificent creatures are vulnerable to extinction.

The Galapagos Land Iguanas, a once abundant and striving species, are now on the verge of extinction. When Charles Darwin first came to the Galapagos in 1835 to study, the iguanas were so abundant that, according to him, it was difficult to even find a place to put up a tent. However, as people began inhabiting the islands, the Galapagos Land Iguana population has been on the decline and have even gone extinct on some of the islands. As people came to the Galapagos to explore, they brought with them many new plants and animals. Many of these foreign species, especially the cats, dogs, rats, and goats, which were introduced to the islands, decimated the iguana population. The goats ate much of the bountiful vegetation consuming the iguanas’ main food source, the dogs preyed on both adult and juvenile iguanas, while the cats preyed on only the juveniles. As a result, the once plethora population of iguanas has decreased so dramatically that now there is currently only an estimated five thousand to ten thousand land iguanas left in the world.

Both the Galapagos Land Iguana and the Santa Fe Land Iguana have similar reproduction characteristics, although their mating season may differ from island to island. Both are very territorial and extremely aggressive when it comes to impressing the females. After they have mated, the females will travel miles, sometimes up to nine miles, in order to find a suitable nest site.The female then dig a hole about a foot and a half deep, in which to lay her eggs, which can range from two to twenty-five eggs. About three to four months later the eggs will hatch and the baby iguanas will make their way to the surface with an eye out for any predators. During the iguanas first few years, they are the most vulnerable and have little defense to any larger predator, as they do not reach maturity until after eight to fifthteen years.
The unique and extremely unusual Pink Land Iguana, which lives only on the northern side of Isabela Island on the Wolf Volcano, is an entirely separate species from the Galapagos Land Iguanas. They were first discovered in 1986 but remained unstudied until the early 2000’s. Also, no juvenile Pink Land Iguana has ever been spotted, and as a result not much is known for sure about this rare creature, except for that they are pink with dark stripes (sometimes) and that have a similar body structure as the Galapagos Land Iguana. These extremely rare Iguanas are on an island with an active volcano. Any eruption could eliminate these critically endangered iguanas.

Is there anything that can be done to assist the revival of the pink land iguana's population?

Sources:

Evolution of the Galapagos
Land Iguanas

The Pink Land Iguana

Galapagos Land Iguana Picture

Santa Fe Land Iguana Picture

Pink Land Iguana Picture

Land Iguana Diet and Reproduction