Animal Behavior Lab An Ethogram on the Green Iguana Lecturer: Dr. P. Deluca Due Date: 2. 10. 12 Classification Kingdom | Animlia | Phylum | Chordata | Subphylum | Vertebrata | Class | Reptilia | Order | Squamata | Suborder | Sauria | Family | Iguanidae | Subfamily | Iguania | Genus | Iguana | Species | iguana | Introduction: The Green Iguana (Iguana iguana) was studied at Ardastra Gardens and Zoo in Nassau, Bahamas for approximately two hours on September 25th 2012.
The Green Iguana is a large, arboreal herbivorous species of lizard of the genus Iguana native to Central, South America, and the Caribbean (Meshaka et al. , 2007). They are active during the day, feeding on leaves, flowers, and fruit. They generally live near water and are excellent swimmers. If threatened, they will leap from a branch, often from great heights, and escape with a splash to the water below (Meshaka et al. , 2007). Furthermore, they possess a row of spines along their backs and along their tails which helps to protect them from predators (Meshaka et al. 2007). Their whip-like tails can be used to deliver painful strikes and like many other lizards, when grabbed by the tail, the iguana can allow it to break, so it can escape and eventually regenerate a new one (Meshaka et al. , 2007). In addition, iguanas have well developed dewlaps which help regulate their body temperature. This dewlap is used in courtships and territorial displays (Meshaka et al. , 2007). The habitat of these iguanas was tropical warm and wet. The weather on that day ranged from 93°F to 95°F. Methods: The green iguanas were studied using Focal sampling.
With this method, the green iguana was located and its behavior was observed for a standard time. During this focal study, the following data was recorded as they occur: * the context (date, time, location, weather, habitat, social context) * the sequence of behaviors * the duration of behaviors (using a stopwatch) Name of behavior: Head-Bobbing During this observation, the green iguana (Iguana iguana) began this behavior by raising its body up and moving its head up and down. The time or duration of this behavior was between 12:18 pm- 1:39 pm.
There were different modes of this behavior that was interpreted and could have been an indication of threat, a harmless greeting or protection of territory. The bobbing of the green iguana may also probably be done in a variety of situations and signaling of different things. The most notable description of this bobbing is the usual straight up and down with a minor side-to-side movement, which is vibrated quickly in the up-down-sideways mode. When bobbing is completed, the head is kept raised upwards after the last movement. This is held for a moment or two, followed by an up-and-down bob again.
This process occurs when the iguana sees another one of its kind (neighbor), other lizards such as the brown anole and curly tail lizard and people visiting the zoo. When an individual would stay more than 10- 15 minutes the green iguana body will settle down into a relaxed, laying down position rather than the raised and laterally compressed body position that typically accompanies the aggressive bobs. This behavior occurred in three different sessions and they lasted on an average of thirteen (13) minutes and giving a total of thirty nine (39) minutes.
The first observation of the green iguana was one of the slowest movements of its head when approached by a nearby lizard of a different species such as the brown anole that was passing by within the territory of the green iguana. This slow head bobbing appeared to be in a form of a greeting to the brown anole. At first however, the green anole was lying flat on its stomach not doing much and when the brown anole came pass, the green iguana changed its body posture by raising the body and flaring its dewlap (small pulsation of dewlap).
However, the slight bobbing became more of an advertisement that the iguana was concerned about its territorial rights. During the second observation, another green iguana that was sharing the same territory with the previous green iguana being studied appeared in the nearby area. When this happened, the green iguana (studied individual) bobbing changes its frequency or rate and became more rapid. This was probably an attempt to indicate that it was becoming more annoyed and offended by the trespassing of the other green iguana.
It also had appeared to be warning the other iguana away from its basking area. During this behavior, the head is vibrated quickly in the up-down-sideways mode, and its head was kept raised upwards after the last movement. This was held momentarily followed by an up-and-down bob, as stated previously. However during the final bobbing observation, the green iguana head was moving in a slow jerking motion that was accompanied with little sneezing. This occurred approximately 1:22pm. During this observation, there were no visible stressors in its environment.
It was also moving along a piece of log and extending its dewlap. The dewlap is the fan like structure that hangs beneath the chin of the green iguana. The extension of the dewlap only lasted momentarily and it began to fold and tuck up under its chin, as if it was a sign of submission. This behavior lasted for approximately 8 minutes. Reference: Meshaka, E. W. , Smith, T. H. , Golden, E. , et al. (2007). Green Iguanas (Iguana iguana): The Unintended Consequence of Sound Wildlife Management Practices. Herpetological Conservation and Biology. 2(2):149-156.