Lesser Antilles iguana
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Lesser Antilles Iguana ( Iguana delicatissima ) |
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| Laurenti , 1768 |
The Lesser Antilles iguana ( Iguana delicatissima ; sometimes also referred to as the green island iguana ) is a large tree-dwelling lizard from the genus Iguana . The species, which is critically endangered, is only found on islands in the Lesser Antilles ( Anguilla , St. Martin , Les Iles Fregates , St. Eustatius , St. Barthelemy , Ile Chevreau and Ile Fourchue , Barbuda , St. Kitts , Nevis , Antigua , Guadeloupe and Îles des Saintes , La Désirade , Dominica , Martinique and Gros îlet ) in the eastern Caribbean . The specific epithet delicatissima means “very delicious” translated from Latin and refers to the meat of the animals, which is considered to be very tender and tasty. The species was first described in 1768 by the Austrian naturalist Josephus Nicolaus Laurenti .
description
Male Lesser Antilles iguanas, not including the tail, can reach a maximum length of around 43 cm, while females measure around 40 cm. The maximum size of the animals, however, varies greatly from island to island. Juvenile specimens show a bright lime green to apple green coloration, in adult animals this changes from the extremities to a brownish gray with increasing age. This process generally begins earlier in male iguanas, and it is also known from some populations that the females retain the color of the young for life. The scales in the cheek area are generally larger than on the rest of the body and show a lighter, creamy-white color that changes to pink during the mating season. A single row of spikes runs along the back and head. Both sexes have a pronounced flap of skin on the throat that does not stand out from the rest of the body in terms of color. The long toes with claws, which are adapted to a tree-dwelling way of life, are striking.
The species shows a clear sexual dimorphism , the males are generally bigger and heavier, especially the head is less graceful. In addition, males have a protruding hump on the back of their head as well as wider cheeks and longer back spines. The femoral pores are also more pronounced in males than in females.
behavior
The animals are diurnal and hide in caves or under stones at night. During the day they go looking for food and can usually be found on trees as skilled climbers. In the event of a threat, Lesser Antilles iguanas defend themselves with powerful bites or deal blows with their large claws or their hard, rough tails.
The lizards generally have a herbivorous diet. In addition to fruits, leaves, seeds and flowers of various plant species , part of the diet is also bird eggs and carrion if available. In captivity, the animals accept mangoes , bananas , lettuce, raw meat and eggs, among other things . Depending on what is available on the inhabited islands, the food consumed can vary considerably from population to population.
Reproduction
The females of the Lesser Antilles iguana dig a hole in the ground once a year from April to June, in which an average of twelve to 13 eggs are laid and then covered again with earth. The number of eggs per clutch, however, varies greatly, one in the years 2008 to 2010 by Knapp et al. Study carried out on Dominica documented clutches with a minimum of four to a maximum of 26 eggs. The number of eggs found strongly depended on the size of the respective female, with larger females laying significantly more eggs. In many cases, the females migrate over short distances to create the nest, as locations seemingly near the coast are preferred for the nest. Every year some animals are killed while crossing roads. Females who set up their nests relatively early have a general disadvantage, as clutches are repeatedly unintentionally dug up by later breeding females when building their own nests. The average weight of the eggs is about 19.6 g with a length of 45.3 mm and a width of 29.5 mm. The breeding season is quite long, the young do not hatch until August and September. The researchers identified two typical time windows - between 6:30 a.m. and 10:00 a.m. in the morning and between 1:00 p.m. and 4:00 p.m. in the afternoon - during which the young animals burrow heaped up from the earth.
Spread and endangerment
The Lesser Antilles iguana inhabits dry forests, grassland areas, mangroves and rainforests up to a height of about 700 m above sea level. The current distribution area extends over a few islands in the Lesser Antilles, including Anguilla , Bonaire , Sint Eustatius , Dominica, Guadeloupe , Martinique and Saint-Barthélemy . Historically, the species has also been found in St. Kitts and Nevis , Antigua and Barbuda and St. Martin , but here it has already disappeared. The IUCN classifies the Lesser Antilles Iguana as critically endangered ( status " critically endangered ") and currently goes out of a total of about 13,000 to 20,000 adult animals.
Juvenile animals are hunted by other lizards ( e.g. Ameiva fuscata ), Antilles slender snakes , red cliff crabs and great falcons . Furthermore, every year many females fall victim to road traffic on the islands while migrating to their nesting sites. In order to reduce the number of animals killed in this way, campaigns to raise awareness among the population were carried out at least in Dominica and information boards were set up on the streets affected. As a result, the number of lizards run over on the island fell by almost 50%. Other threats to the species are the fragmentation and destruction of their habitat due to increasing human settlement and land requirements for agriculture, as well as hunting by introduced dogs and cats. However, competition from the closely related green iguana ( Iguana iguana ), which is an invasive species on the islands of the Lesser Antilles, is considered a decisive factor in the extinction of populations in a large part of the historical range . In addition to the displacement by the green iguana, there is also a rapid hybridization of the two species, where they are present together, which represents an additional threat to the continued existence of the Lesser Antilles iguana.
The hunt for the animals is now prohibited in the entire distribution area and has fallen sharply after the population figures collapsed. Historically, the hunting of the animals for consumption is clearly traceable, and in recent years, as a result of other food sources breaking away, for example after hurricanes , specimens have been caught by the locals again and again.
Web links
Wikispecies: Lesser Antilles Iguana - Species DirectoryIndividual evidence
- ^ Iguana delicatissima in The Reptile Database
- ↑ Lesser Antilles iguana (Iguana delicatissima). In: zoovienna.at. Schönbrunn Zoo, accessed on January 25, 2019 .
- ↑ Josephi Nicolai Laurenti: Specimen medicum, exhibens synopsin reptilium emendatam cum experimentis circa venena et antidota reptilium austracorum, quod authoritate et consensu . Vienna 1768, p. 217 ff .
- ↑ SA Pasachnik, M. Breuil, R. Powell: Iguana delicatissima . In: Society for the Study of Amphibians and Reptiles (Ed.): Catalog of American Amphibians and Reptiles . February 15, 2006, p. 811 .
- ↑ Whitney J. Priesmeyer: Observations on Iguana delicatissima and Conservation Status on Dominica. In: tamu.edu. Texas A&M University, 2006, accessed January 28, 2019 . (PDF)
- ↑ Tim van Wagensveld: The Biology and Distribution of Iguana delicatissima on St. Eustatius. In: ircf.org. International Reptile Conservation Foundation, November 2015, accessed January 28, 2019 . (PDF)
- ^ LCM Wijffels: Een nieuwe ontmoeting met de Antillenleguaan (Iguana delicatissima). In: lacerta.nl. 1997, archived from the original on February 16, 2018 ; Retrieved October 15, 2019 (Dutch).
- ↑ James D. Lazell, jr .: The lizard genus Iguana in the Lesser Antilles . In: Bulletin of the Museum of Comparative Zoology . No. 145 , 1973, pp. 21-22 .
- ^ A b Charles R. Knapp, Lindon Prince, Arlington James: Movements and nesting of the Lesser Antillean Iguana (Iguana delicatissima) from Dominica, West Indies: Implications for conservation . In: Herpetological Conservation and Biology . No. 11 , June 12, 2016, p. 154-167 .
- ↑ a b M. van den Burg, M. Breuil, C. Knapp: Iguana delicatissima. The IUCN Red List of Threatened Species. In: iucnredlist.org. IUCN, 2018, accessed January 25, 2019 .
- ↑ Lesser Antillean Iguana. In: ircf.org. International Reptile Conservation Foundation, accessed January 28, 2019 .