Habitat preference of Iguana delicatissima and the hybrid crossing with Iguana iguana

The Lesser Antillean Iguana (Iguana delicatissima) is endemic to Sint Eustatius as well as other islands of the Lesser Antilles. Since 2010 I. delicatissima is classified as endangered on the IUCN Red List. Iguana delicatissima has various threats for a longer period, but since last year a new threat has presented itself. The Common Green Iguana (Iguana iguana) was found on the island. The presence of the I. iguana is a serious threat for the I. delicatissima due to hybridization and habitat competition. In this study there is researched what the habitat preference is of I. delicatissima and the hybrid. Besides the habitat preference the distribution of the iguanas is mapped. With this information it hopefully will be easier to find the iguanas and STENAPA will be able to save the I. delicatissima from hybridization. Twelve transects were walked all over the island. Also is information obtained from citizens and opportunistic data is used. The exact location, plant species and whether the iguana was found in the sun were documented. To see if iguanas have a significant preference for sunlight a binomial test has been used. A total of 72 I. delicatissima were caught and the data of 7 hybrids was used. Of the 72 I. delicatissima 13 were found on the ground and of the 7 hybrids 5 were found on the ground. Most of the I. delicatissima were found in trees of which is known to be used as food. One of the hybrids was found in a same plant species which also I. delicatissima was found in. There was too little data to compare the hybrids with I. delicatissima. In the sun were significantly (p=0,013) more iguanas found than in the shade. There was a high density of individuals at the Welfare street, Mansionweg and Lodiweg. Most hybrids were found in one square kilometer. Concluding there was no significant difference found in habitat preference between the I. delicatissima and the hybrids. There were significantly more iguanas found in the sun compared to the shade. Iguana delicatissima was found widely spread over the island while the hybrids were found within one square kilometer. It is advised to keep documenting the plants the hybrids are found in to be able to say something about the habitat preference. Also it is recommended to place camera traps at nests in the area were hybrids have been found. This way you know if the juveniles are I. delicatissima or hybrids and if the problem is increasing or decreasing.

[Student report]

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