Marine Iguana - BKS


 * Marine Iguanas are found only on the Galapagos Islands and are well adapted for life in the sea for example their long tails which allows efficient movement through strong waves.
 * However they must come ashore to breed.
 * Like all reptiles Marine Iguanas are ectotherms, which means they cannot control their body temperature internally like we mammals, and birds do. Their body temperature is controlled primarily by their external environment.
 * For example when their temperature is low, they tend to bask in the sunlight by lying across rocks to warm themselves up. Thermal images show that this is particularly effective in increasing the iguana's body temperature. However this is a long process and the iguanas cannot move effectively until their body temperature has returned to normal - 35.5 degrees Celsius. During this time they are more vulnerable to predators. Thus they become very defensive during this time - often biting any potential threats.
 * However despite this, it has been noted that the activity of Marine Iguanas is not as reduced as other ectotherms due to the fact that they can move blood away from their surface to conserve heat and drastically reduce their heart rate.
 * Despite the tropical location of the Galapagos Islands, the body temperature of Marine Iguanas can drop by around ten degrees Celsius after a dive in the water. This much change in body heat would most probably be fatal to a human but these animals simply return to shore and lie in the hot sun to regain warmth.
 * Likewise when they get too hot, they spend more time in the shade or sit in a crack in a rock to cool their temperature down before moving around again.
 * An interesting activity of Marine Iguanas is that they often cover each other and provide shade to one another when it's too hot, and at night tend to gather in large numbers to conserve body heat.
 * They have also been found to adapt their size according to availability of food. During an El Niño cycle (the temperature of the sea surface became anomalously warm/cold) food diminished for two years. However Marine Iguanas continued to survive by decreasing their length by as much as 20%. When food supply returned to normal, iguana size also increased. Research suggests that the iguanas secreted a stress hormone during this time that induced decreased skeletal size.
 * This species is protected by the laws of Ecuador and listed in CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora).