dcsimg

Lifespan, longevity, and ageing

tarjonnut AnAge articles
Maximum longevity: 15 years (wild)
lisenssi
cc-by-3.0
tekijänoikeus
Joao Pedro de Magalhaes
muokkaaja
de Magalhaes, J. P.
kumppanisivusto
AnAge articles

Benefits ( englanti )

tarjonnut Animal Diversity Web

This species was observed by Darwin early in the 19th Century; Darwin noted its similarity to iguanas on the South American mainland, as well as its obvious adaptations to local conditions. These and other observations of Galapagos wildlife contributed in part to Darwin's theory of evolution.

Today the Land Iguanas are an important part of the unique Galapagos fauna, and studies of their biology, as well as conservation programs, are continuing.

lisenssi
cc-by-nc-sa-3.0
tekijänoikeus
The Regents of the University of Michigan and its licensors
bibliografinen lainaus
Bruin, T. 2000. "Conolophus subcristatus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Conolophus_subcristatus.html
tekijä
Tami Bruin, Michigan State University
muokkaaja
James Harding, Michigan State University
alkuperäinen
käy lähteessä
kumppanisivusto
Animal Diversity Web

Conservation Status ( englanti )

tarjonnut Animal Diversity Web

The Galapagos Land Iguana is listed as a threatened species by the World Conservation Union (Baillie and Groombridge 1996). Threats include destruction of eggs and young lizards by introduced rats and cats, and destruction of food plants by introduced goats.

IUCN Red List of Threatened Species: vulnerable

lisenssi
cc-by-nc-sa-3.0
tekijänoikeus
The Regents of the University of Michigan and its licensors
bibliografinen lainaus
Bruin, T. 2000. "Conolophus subcristatus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Conolophus_subcristatus.html
tekijä
Tami Bruin, Michigan State University
muokkaaja
James Harding, Michigan State University
alkuperäinen
käy lähteessä
kumppanisivusto
Animal Diversity Web

Benefits ( englanti )

tarjonnut Animal Diversity Web

No adverse effects.

lisenssi
cc-by-nc-sa-3.0
tekijänoikeus
The Regents of the University of Michigan and its licensors
bibliografinen lainaus
Bruin, T. 2000. "Conolophus subcristatus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Conolophus_subcristatus.html
tekijä
Tami Bruin, Michigan State University
muokkaaja
James Harding, Michigan State University
alkuperäinen
käy lähteessä
kumppanisivusto
Animal Diversity Web

Trophic Strategy ( englanti )

tarjonnut Animal Diversity Web

The Land Iguana is largely a vegetarian. The prickly pear cactus (Opuntia) is a major food source; the lizard eats the cactus fruit and leaves by moving the cactus around in its mouth until all the spines are worked off (Mattison 1989).

lisenssi
cc-by-nc-sa-3.0
tekijänoikeus
The Regents of the University of Michigan and its licensors
bibliografinen lainaus
Bruin, T. 2000. "Conolophus subcristatus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Conolophus_subcristatus.html
tekijä
Tami Bruin, Michigan State University
muokkaaja
James Harding, Michigan State University
alkuperäinen
käy lähteessä
kumppanisivusto
Animal Diversity Web

Distribution ( englanti )

tarjonnut Animal Diversity Web

The Galapagos Land Iguana is native to the Galapagos Islands, off the coast of Ecuador. It is formerly widely distributed on these islands, though its numbers are now greatly reduced (Mattison 1989, Cogger and Zweifel, 1998).

Biogeographic Regions: oceanic islands (Native ); pacific ocean (Native )

lisenssi
cc-by-nc-sa-3.0
tekijänoikeus
The Regents of the University of Michigan and its licensors
bibliografinen lainaus
Bruin, T. 2000. "Conolophus subcristatus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Conolophus_subcristatus.html
tekijä
Tami Bruin, Michigan State University
muokkaaja
James Harding, Michigan State University
alkuperäinen
käy lähteessä
kumppanisivusto
Animal Diversity Web

Habitat ( englanti )

tarjonnut Animal Diversity Web

The lizards live in land burrows, which offer protection from the hot sun. Many islands on which the iguanas live are quite arid.

Terrestrial Biomes: scrub forest

lisenssi
cc-by-nc-sa-3.0
tekijänoikeus
The Regents of the University of Michigan and its licensors
bibliografinen lainaus
Bruin, T. 2000. "Conolophus subcristatus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Conolophus_subcristatus.html
tekijä
Tami Bruin, Michigan State University
muokkaaja
James Harding, Michigan State University
alkuperäinen
käy lähteessä
kumppanisivusto
Animal Diversity Web

Morphology ( englanti )

tarjonnut Animal Diversity Web

The Galapagos Land Iguana is yellow or brown in color with spots throughout its ventrum and dorsum. A spikey dorsal crest runs along the neck and back. This is a large (>48 in), heavy bodied lizard, with thick back legs and smaller front legs. There are long, sharp claws on its toes. It has a short blunt head and pleurodont teeth. Its tail is quite a bit longer than its trunk. (Mattison 1989).

lisenssi
cc-by-nc-sa-3.0
tekijänoikeus
The Regents of the University of Michigan and its licensors
bibliografinen lainaus
Bruin, T. 2000. "Conolophus subcristatus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Conolophus_subcristatus.html
tekijä
Tami Bruin, Michigan State University
muokkaaja
James Harding, Michigan State University
alkuperäinen
käy lähteessä
kumppanisivusto
Animal Diversity Web

Life Expectancy ( englanti )

tarjonnut Animal Diversity Web

Average lifespan
Status: captivity:
15.0 years.

Average lifespan
Sex: male
Status: captivity:
7.3 years.

lisenssi
cc-by-nc-sa-3.0
tekijänoikeus
The Regents of the University of Michigan and its licensors
bibliografinen lainaus
Bruin, T. 2000. "Conolophus subcristatus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Conolophus_subcristatus.html
tekijä
Tami Bruin, Michigan State University
muokkaaja
James Harding, Michigan State University
alkuperäinen
käy lähteessä
kumppanisivusto
Animal Diversity Web

Reproduction ( englanti )

tarjonnut Animal Diversity Web

These lizards have a mating ritual where the male agressively courts the female. Males defend territories around their burrows that both they and females use as shelter, and most courtship occurs around these burrows. Females are attracted to male's territories with burrows, but these burrows are not used for nesting. (Werner 1982).

Female Land Iguanas lay soft-shelled eggs with permeable shells. About 25 eggs are laid in burrows in moist sand or under leaf litter. On the arid, rocky island of Fernandina, females may travel more than 15 km to find good nest sites, sometimes within the crater of a dormant volcano. When places to lay eggs become scarce, competition between females occurs and some eggs already laid may be disturbed by another iguana (Werner 1983, Mattison 1989). Hatchlings appear in about three to four months, and may take about a week to dig out of the nest cavity (Terraquest 1996).

lisenssi
cc-by-nc-sa-3.0
tekijänoikeus
The Regents of the University of Michigan and its licensors
bibliografinen lainaus
Bruin, T. 2000. "Conolophus subcristatus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Conolophus_subcristatus.html
tekijä
Tami Bruin, Michigan State University
muokkaaja
James Harding, Michigan State University
alkuperäinen
käy lähteessä
kumppanisivusto
Animal Diversity Web

Biology ( englanti )

tarjonnut Arkive
Galapagos land iguanas are active during the day. They maintain their body temperature by basking in the sun to warm up and seeking shade when they become too hot. In the morning they can be found basking, but during the heat of midday they tend to retreat into shade. At night they sleep in burrows which they dig themselves (5). This species is omnivorous but tends to mainly eat plants and the fruits and pads of cactus trees. They may remove the spines with their claws, and these cacti provide them with plenty of moisture during dry spells (2) (5). This species has an interesting relationship with Galapagos finches; the iguanas often raise themselves from the ground and allow the finches to remove ticks from their bodies (2). Males defend territories, with displays involving head bobbing, biting and tail thrashing (5). During courtship, males aggressively court the females (4). After mating, the females set off on a migration to suitable egg-laying habitat. On Ferdinanda Island, females are known to travel up to 15 km to reach a suitable nesting site (4). They then lay two to 20 eggs in a 50 cm deep burrow. The nest site is guarded for a number of days after laying, in order to prevent other females from laying in the same place and damaging the eggs (5). The young hatch after 85 to 110 days; it then takes them up to a week to dig their way out of the burrow (5). Maturity is reached between eight and 15 years. If they survive the first years of life, when they are most vulnerable to predation and food scarcity, land iguanas can live for up to 50 years (2).
lisenssi
cc-by-nc-sa-3.0
tekijänoikeus
Wildscreen
alkuperäinen
käy lähteessä
kumppanisivusto
Arkive

Conservation ( englanti )

tarjonnut Arkive
In 1976, wild dogs wiped out the last colonies of land iguanas around Conway Bay on Santa Cruz Island. This prompted the Charles Darwin Research Station (CDRS) and the Galapagos National Park Service (GNPS) to initiate an emergency rescue scheme for the 60 remaining survivors. They then discovered that a similar level of destruction was occurring on Isabella Island. The GNPS and CDRS established a recovery programme, including a captive breeding scheme based on Santa Cruz. The captive breeding programme continues today, and land iguanas are returned to the wild when they reach a size beyond which they are safe from cat predation (2) (6). This breeding programme is accompanied by a campaign to work towards the eradication and tighter control of introduced animals. Other important measures include the maintenance of suitable habitat for the species, and continued monitoring of the populations (2).
lisenssi
cc-by-nc-sa-3.0
tekijänoikeus
Wildscreen
alkuperäinen
käy lähteessä
kumppanisivusto
Arkive

Description ( englanti )

tarjonnut Arkive
There are two species of land iguana found in the Galapagos; this species Conolophus subcristatus, is found on six islands and Conolophus pallidus is found only on Santa Fe (2). This species is very large, growing to lengths of over a meter (2). The short head is blunt and the back legs are thick and powerful, with long sharp claws on the toes (4). It is yellowish in colour with blotches of white, black, rust and brown (5) and a row of spines passes along the centre of the neck and back (4).
lisenssi
cc-by-nc-sa-3.0
tekijänoikeus
Wildscreen
alkuperäinen
käy lähteessä
kumppanisivusto
Arkive

Habitat ( englanti )

tarjonnut Arkive
This iguana lives in the drier areas of the islands on which they occur, in scrubby habitats (5) (4). Females require access to areas of sandy or loose soil in which to lay their eggs; some females even use the ash around dormant volcanic craters (4).
lisenssi
cc-by-nc-sa-3.0
tekijänoikeus
Wildscreen
alkuperäinen
käy lähteessä
kumppanisivusto
Arkive

Range ( englanti )

tarjonnut Arkive
Land iguanas are endemic to the Galapagos Islands off the coast of Ecuador (4). Conolophus subcristatus is native to six islands (2). In 1835 when Charles Darwin first went to the Galapagos, land iguanas were extremely numerous; he wrote: “I cannot give a more forcible proof of their number, then by stating that when we were left at Santiago Island, we could not for some time find a spot free from their burrows on which to pitch our single tent”. Sadly, this once thriving Santiago Island population has become completely extinct (6).
lisenssi
cc-by-nc-sa-3.0
tekijänoikeus
Wildscreen
alkuperäinen
käy lähteessä
kumppanisivusto
Arkive

Status ( englanti )

tarjonnut Arkive
Classified as Vulnerable (VU D2) by the IUCN Red List (1) and listed on Appendix II of CITES (3).
lisenssi
cc-by-nc-sa-3.0
tekijänoikeus
Wildscreen
alkuperäinen
käy lähteessä
kumppanisivusto
Arkive

Threats ( englanti )

tarjonnut Arkive
In the early 1800s, whalers and settlers came to the Galapagos Islands. It is likely that they ate land iguanas, but the most serious problem they caused resulted from the introduction, both accidental and deliberate, of predators such as cats and dogs and domestic animals such as goats and pigs (6). Introduced animals are still the main threat facing this species today (2). Cats and rats hunt eggs and young iguanas and introduced goats destroy food plants (4). The natural predators of land iguanas include hawks, herons, and snakes, all of which cannot prey on young after they reach around one year of age, as they become too large. However, cats can continue to kill young iguanas until they reach three or four years of age; cat predation is a huge problem preventing the natural success of the species (5).
lisenssi
cc-by-nc-sa-3.0
tekijänoikeus
Wildscreen
alkuperäinen
käy lähteessä
kumppanisivusto
Arkive

Igwan-douar Galápagos ( bretoni )

tarjonnut wikipedia BR

Igwan-douar Galápagos(Daveoù a vank) (Conolophus subcristatus) zo ur stlejvil a vev war inizi Galápagos.

 src=
Penn un igwan-douar Galápagos


Igwan-douar Galápagos

lisenssi
cc-by-sa-3.0
tekijänoikeus
Wikipedia authors and editors
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia BR

Igwan-douar Galápagos: Brief Summary ( bretoni )

tarjonnut wikipedia BR

Igwan-douar Galápagos(Daveoù a vank) (Conolophus subcristatus) zo ur stlejvil a vev war inizi Galápagos.

 src= Penn un igwan-douar Galápagos


lisenssi
cc-by-sa-3.0
tekijänoikeus
Wikipedia authors and editors
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia BR

Leguán galapážský ( Tšekki )

tarjonnut wikipedia CZ

Leguán galapážský (Conolophus subcristatus) je endemitem Galapág (Ekvádor), vyskytující se asi na šesti zdejších ostrovech (např. na ostrovech Fernandina, Isabela, Santa Cruz nebo již vzácně na ostrově Santiago). Je to velký druh vejcorodého ještěra, který roste do délky více než jednoho metru, a může vážit až 10 kilogramů. Živí se až z 80 % kaktusy.

Popis

Jeho tělo hraje několika různými barvami; hlavu a silné končetiny má nažloutlé až bíle, zatímco zbytek těla a hřbet má rezavě hnědý až černý nádech. Vůči tělu je jeho hlava poměrně malá a jeho hřbet je posetý řadou trnů, zřetelných v oblasti krku.[2]

Způsob života

Leguán galapážský je aktivní během dne. Jako studenokrevný plaz se často jen vyhřívá na slunci a v takovém rozpoložení jej můžeme spatřit především v dopoledních hodinách. V poledne, kdy je žár slunce již neúnosný, zalézá raději do stínu. Za šera se pak uchyluje k spánku a mizí do své nory. Leguán galapážský je všežravec,[2] ale živí se často ovocem, především pak různými kaktusy (z nichž nejčastěji opunciemi),[3] podobně jako jeho příbuzný leguán bledý (Conolophus pallidus). Pomocí drápů odstraňuje z kaktusu ostnaté trny, nebo je polyká s nimi. Tento sukulent vyhledává obzvlášť v období sucha, protože poskytuje dostatek vláhy. Leguán galapážský udržuje zajímavý vztah s galapážskými pěnkavami; v jejich přítomnosti se odlepí od země a nechává si jimi odstranit klíšťata a jiné parazity z břicha.[2]

Samec je teritoriální, své území brání výhružnými signály (kývání hlavou), a pokud je narušitel nebere na zřetel, může dojít k útoku, kdy nepřítele pokouše nebo praští ocasem.[2] V období námluv na samice až agresivně doléhá.[2] Po páření naleznou samice vhodné místo pro nakladení vajíček. Někdy tak vyrážejí až na 15 km dlouhou pouť, aby našly vhodnou a bezpečnou půdu; některé samice kladou snůšku přímo do sopečného popela.[2][3] Do vyhrabané nory, asi 50 cm hluboké,[2] pokládá až 25 vajec[3]. Zprvu je nějakou dobu střeží, aby na stejné místo nenakladla svá vejce jiná samice, čímž by mohla její snůšku poškodit. Mláďata se líhnou po 85 až 110 dnech[2] a do jednoho týdne se vyhrabou z nory. První roky jsou leguáni velmi zranitelní. Do dospělosti vyrostou až za poměrně dlouhou dobu, v 15 letech,[2] ale můžou se dožít až 50 let.[2] V zajetí se dožívají průměrně 15 let.[3]

Ohrožení

Mezi přirozené predátory se řadí jestřábi, volavky nebo hadi, kteří loví mladé leguány ve věku 1–2 let. Avšak ani starší nemají vyhráno, jsou pro ně velkou hrozbou invazivní predátoři, jako je divoká kočka domácí.[2][3]

V 1819. století se leguán galapážský dostal na jídelní stůl někdejších lovců velryb či osadníků. V současnosti (k roku 2017) patří mezi největší hrozby invazivní druhy živočichů, kteří jsou na těchto ostrovech značně rozšíření (predace ze strany koz a prasat, a právě noví predátoři jako kočka domácí).[2][3] Na seznamu ohrožených druhů Mezinárodního svazu ochrany přírody je uveden jako zranitelný druh.[4] Na Galapážských ostrovech žije dnes asi 5000 až 10 000 těchto leguánů.

Odkazy

Reference

  1. Červený seznam IUCN 2018.1. 5. července 2018. Dostupné online. [cit. 2018-08-09]
  2. a b c d e f g h i j k l Galapagos land iguana videos, photos and facts - Conolophus subcristatus. Arkive [online]. [cit. 2017-07-17]. Dostupné online. (anglicky)
  3. a b c d e f Conolophus subcristatus (Galapagos Land Iguana). Animal Diversity Web [online]. [cit. 2017-07-17]. Dostupné online. (anglicky)
  4. Conolophus subcristatus (Common Land Iguana, Galapagos Land Iguana, Galápagos Land Iguana). www.iucnredlist.org [online]. [cit. 2017-07-17]. Dostupné online.

Externí odkazy

Logo Wikimedia Commons Obrázky, zvuky či videa k tématu leguán galapážský ve Wikimedia Commons

lisenssi
cc-by-sa-3.0
tekijänoikeus
Wikipedia autoři a editory
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia CZ

Leguán galapážský: Brief Summary ( Tšekki )

tarjonnut wikipedia CZ

Leguán galapážský (Conolophus subcristatus) je endemitem Galapág (Ekvádor), vyskytující se asi na šesti zdejších ostrovech (např. na ostrovech Fernandina, Isabela, Santa Cruz nebo již vzácně na ostrově Santiago). Je to velký druh vejcorodého ještěra, který roste do délky více než jednoho metru, a může vážit až 10 kilogramů. Živí se až z 80 % kaktusy.

lisenssi
cc-by-sa-3.0
tekijänoikeus
Wikipedia autoři a editory
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia CZ

Drusenkopf ( saksa )

tarjonnut wikipedia DE
 src=
Drusenkopf

Der Drusenkopf (Conolophus subcristatus), auch als Galapagos-Landleguan bekannt, ist eine Art aus der Gattung der Drusenköpfe. Die Tiere leben nur auf den Galápagos-Inseln Isabela, Fernandina und Santa Cruz, sowie deren Nebeninseln Baltra, Seymour Norte und Plaza Sur. Auf Santiago, wo Charles Darwin sie seinerzeit noch massenhaft antraf, wurden sie ausgerottet. – Auf der Galapagos-Insel Santa Fe lebt der Santa Fe-Drusenkopf (Conolophus pallidus).

Merkmale

Drusenköpfe sind große, schwer gebaute Echsen mit kräftigen Beinen und mit starken Krallen versehenen Füßen. Sie werden 1,20 Meter lang und sind gelb oder braun gefärbt. Der Kopf ist kurz und endet stumpf. Ein stachliger Kamm zieht sich über den Nacken und den Rücken. Der Schwanz ist etwas länger als Kopf und Rumpf zusammen.

Lebensweise

Drusenköpfe bewohnen selbst gegrabene Erdhöhlen, in denen sie vor der starken Sonneneinstrahlung geschützt sind. Sie sind Pflanzenfresser und ernähren sich z. B. von Sprossen und Blüten der Opuntien. Die Stacheln entfernen sie, indem sie die Pflanzenteile mit dem Fuß auf dem Erdboden herumrollen. Ihren Wasserbedarf decken sie teilweise durch den Verzehr der Kakteen.

Fortpflanzung

Männchen verteidigen Territorien um ihre Höhlen, die sowohl von ihnen als auch von Weibchen als Unterschlupf genutzt werden. Die Weibchen legen ihr Gelege aus bis zu 25, mit einer weichen, lederartigen Schale versehenen Eier in feuchten Sand oder unter Laub. Auf der trockenen und felsigen Insel Fernandina laufen die Weibchen bis zu 15 Kilometer, um gute Nistplätze zu finden, manchmal innerhalb eines erloschenen Vulkankraters. Die Jungtiere schlüpfen nach drei bis vier Monaten.

Quelle

Weblinks

 src=
– Album mit Bildern, Videos und Audiodateien
 title=
lisenssi
cc-by-sa-3.0
tekijänoikeus
Autoren und Herausgeber von Wikipedia
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia DE

Drusenkopf: Brief Summary ( saksa )

tarjonnut wikipedia DE
 src= Drusenkopf

Der Drusenkopf (Conolophus subcristatus), auch als Galapagos-Landleguan bekannt, ist eine Art aus der Gattung der Drusenköpfe. Die Tiere leben nur auf den Galápagos-Inseln Isabela, Fernandina und Santa Cruz, sowie deren Nebeninseln Baltra, Seymour Norte und Plaza Sur. Auf Santiago, wo Charles Darwin sie seinerzeit noch massenhaft antraf, wurden sie ausgerottet. – Auf der Galapagos-Insel Santa Fe lebt der Santa Fe-Drusenkopf (Conolophus pallidus).

lisenssi
cc-by-sa-3.0
tekijänoikeus
Autoren und Herausgeber von Wikipedia
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia DE

Конолофа ( Kirgiisi )

tarjonnut wikipedia emerging languages
 src=
Конолофа (Conolophus subcristatus).

Конолофа (лат. Conolophus subcristatus) — игуана тукумундагы кескелдириктердин бир түрү.

Колдонулган адабияттар

lisenssi
cc-by-sa-3.0
tekijänoikeus
Wikipedia жазуучу жана редактор
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia emerging languages

Galapagos land iguana ( englanti )

tarjonnut wikipedia EN

The Galápagos land iguana (Conolophus subcristatus) is a very large species of lizard in the family Iguanidae. It is one of three species of the genus Conolophus. It is endemic to the Galápagos Islands, in the dry lowlands of the islands of Fernandina, Isabela, Santa Cruz, North Seymour, Baltra, and South Plaza.[1][3][4]

Taxonomy

The land iguanas in the Galápagos vary in morphology and coloration among different populations.[5] In addition to the relatively widespread and well-known Galápagos land iguana (C. subcristatus), there are two other species of Conolophus: the Galápagos pink land iguana (C. marthae) from northern Isabela Island and the Santa Fe land iguana (C. pallidus) from Santa Fe Island.[5][6] Based on mtDNA, land iguanas and marine iguanas diverged about 8–10 million years ago.[7][8] Within the land iguana genus, the oldest split based on mtDNA, about 5.7 million years old, is between C. subcristatus and C. marthae.[8][9] A more recent study that included both mtDNA and nuclear DNA indicates that the marine iguana split from the land iguana about 4.5 million years ago, and among the land iguanas C. subcristatus and C. marthae split from each other about 1.5 million years ago.[10] The differentiation between the last two species, C. subcristatus and C. pallidus, is less clear and it has been questioned whether they are separate species.[5] Based on mtDNA and cytochrome b, they fall into three monophyletic groups: C. subcristatus of western islands (Isabela and Fernandina), C. subcristatus of central islands (Santa Cruz, Baltra and South Plaza) and C. pallidus. Although the exact pattern is uncertain, it is possible that C. pallidus is closer to one of the C. subcristatus groups than the two C. subcristatus groups are to each other.[9]

Its specific name subcristatus is derived from the Latin words sub meaning "lesser" and cristatus meaning "crested", and refers to the low crest of spines along the animal's back, which is not as tall as in most iguanas.

Anatomy and morphology

Charles Darwin described the Galápagos land iguana as "ugly animals, of a yellowish orange beneath, and of a brownish-red colour above: from their low facial angle they have a singularly stupid appearance."[11] The Galápagos land iguana one of the largest lizards in the world[12] growing to a length of 0.9 to 1.5 m (3–5 ft) with a body weight of up to 13 kg (29 lb), depending upon which island they are from.[13][14] Being cold-blooded, they absorb heat from the sun by basking on volcanic rock, and at night sleep in burrows to conserve their body heat.[13] These iguanas also enjoy a symbiotic relationship with birds; the birds remove parasites and ticks, providing relief to the iguanas and food for the birds.[3][15]

Diet and longevity

Feeding
Feeding on fallen cactus pads

Land iguanas are primarily herbivorous; however, some individuals have shown that they are opportunistic carnivores supplementing their diet with insects, centipedes and carrion.[3] Because fresh water is scarce on its island habitats, the Galápagos land iguana obtains the majority of its moisture from the prickly-pear cactus, which makes up 80% of its diet. All parts of the plant are consumed, including the fruit, flowers, pads, and even spines.[3][13] During the rainy season it will drink from available standing pools of water and feast on yellow flowers of the genus Portulaca.[13][15]

The Galápagos land iguana has a 60 to 69 year lifespan.[3][14]

Reproduction

Basking

Galápagos land iguanas become sexually mature anywhere between eight and fifteen years of age, depending on which island they are from.[3] Mating season also varies between islands, but soon after mating, the females migrate to sandy areas to nest, laying 2–20 eggs in a burrow about 50 cm (20 in) deep.[3] The eggs hatch anywhere from 90 to 125 days later.[3][14]

On South Plaza Island, where the territories of marine iguanas and land iguanas overlap, the two sometimes interbreed, resulting in a hybrid iguana that shows a mixture of features from each species.[3] The most likely unions tend to be between male marine iguanas and female land iguanas. Despite their long separation time and their being two distinct species from different genera, the offspring are viable, although likely sterile.[3][5]

Population

It is estimated that between 5,000 and 10,000 land iguanas are found in the Galápagos Islands.[3] These iguanas were so abundant on Santiago Island at one time that naturalist Charles Darwin remarked when it was called King James Island that "...when we were left at James, we could not for some time find a spot free from their burrows on which to pitch our single tent".[13][16] In the years since then, entire populations (including all the animals on Santiago Island) have been wiped out by introduced feral animals such as pigs, rats, cats, and dogs.[3][13]

Evolutionary history

Researchers theorize that Galápagos land iguanas and marine iguanas evolved from a common ancestor since arriving on the islands from South America, presumably by rafting.[17][18] The marine iguana diverged from the land iguana some 8 million years ago, which is older than any of the extant Galápagos islands.[19][7] It is therefore thought that the ancestral species inhabited parts of the volcanic archipelago that are now submerged. The two species remain mutually fertile in spite of being assigned to distinct genera, and they occasionally hybridize where their ranges overlap.

Recovery efforts

Male
Yellow land iguana at the Charles Darwin Research Station
Galápagos land iguana on North Seymour Island.

Beginning in the early 1990s, the Galápagos land iguana has been the subject of an active reintroduction campaign on Baltra Island. These animals became extinct on Baltra by 1954, allegedly wiped out by soldiers stationed there who shot the iguanas for amusement.[3][15] However, in the early 1930s, William Randolph Hearst had translocated a population of land iguanas from Baltra to North Seymour Island, a smaller island just a few hundred metres north of Baltra, because he could not understand why no iguanas were present there. Hearst's translocated iguanas survived and became the breeding stock for the Charles Darwin Research Station captive breeding program that has successfully reintroduced the species to Baltra and a number of other areas.[3] Visitors today frequently see iguanas on both the runway of the Baltra airport or while they cross the road.

References

  1. ^ a b Kumar, K.; Gentile, G.; Grant, T.D. (2020). "Conolophus subcristatus". IUCN Red List of Threatened Species. 2020: e.T5240A3014082. doi:10.2305/IUCN.UK.2020-2.RLTS.T5240A3014082.en. Retrieved 17 November 2021.
  2. ^ "Appendices | CITES". cites.org. Retrieved 2022-01-14.
  3. ^ a b c d e f g h i j k l m n "Land iguanas" (PDF). Charles Darwin Research Station Fact Sheet. Charles Darwin Foundation for the Galapagos Islands. 2006. Archived from the original (PDF) on 2007-06-06. Retrieved 2007-10-14.
  4. ^ Swash, A.; R. Still (2000). Birds, Mammals & Reptiles of the Galápagos Islands. Yale University Press. pp. 118–119. ISBN 0-300-08864-7.
  5. ^ a b c d Rassmann, Kornelia; Markmann, Melanie; Trillmich, Fritz; Tautz, Diethard (2004), "Tracing the Evolution of the Galapagos Iguanas", Iguanas: Biology and Conservation, California: University of California Press, pp. 71–83, ISBN 978-0-520-23854-1
  6. ^ Gentile, Gabriele; Anna Fabiani; Cruz Marquez; Howard L. Snell; Heidi M. Snell; Washington Tapia; Valerio Sbordonia (2009). "An overlooked pink species of land iguana in the Galapagos". Proceedings of the National Academy of Sciences of the United States of America. National Academy of Sciences of the United States of America. 106 (2): 507–11. doi:10.1073/pnas.0806339106. PMC 2626733. PMID 19124773.
  7. ^ a b "Explaining the Divergence of the Marine Iguana Subspecies on Espa". amnh.org.
  8. ^ a b Black, Richard (5 January 2009). "Pink iguana rewrites family tree". BBC News. BBC. Retrieved 20 May 2017.
  9. ^ a b Gentile; Fabiania; Marquez; Snell; Snell; Tapia;and Sbordonia (2009). "An overlooked pink species of land iguana in the Galápagos". Proceedings of the National Academy of Sciences of the United States of America. National Academy of Sciences of the United States of America. 106 (2): 507–511. doi:10.1073/pnas.0806339106. PMC 2626733. PMID 19124773.{{cite journal}}: CS1 maint: uses authors parameter (link)
  10. ^ MacLeod, A.; A. Rodríguez; M. Vences; P. Orozco-terWengel; C. García; F. Trillmich; G. Gentile; A. Caccone; G. Quezada; S. Steinfartz (2015). "Hybridization masks speciation in the evolutionary history of the Galápagos marine iguana". Proceedings of the Royal Society B. 282 (1809): 20150425. doi:10.1098/rspb.2015.0425. PMC 4590447. PMID 26041359.
  11. ^ Darwin, Charles (1989), The Voyage of the Beagle: Charles Darwin's Journal of Researches, New York: Penguin Classics, p. 401, ISBN 978-0-14-043268-8
  12. ^ "The 10 Largest Lizards in The World". a-z-animals.com. 18 August 2021. Retrieved 12 February 2022.
  13. ^ a b c d e f Rogers, Barbara (1990), Galapagos, New York: Mallard Press, p. 144, ISBN 978-0-7924-5192-1
  14. ^ a b c Rosenthal, Ellen (1997), "Days and nights of the iguana: in the Galapagos, a devoted pair work to save land iguanas", Animals
  15. ^ a b c Kricher, John (2006), Galapagos: A Natural History, New Jersey: Princeton University Press, pp. 9, 51, 91, 200, ISBN 978-0-691-12633-3
  16. ^ Darwin, Charles (1839), Narrative of the surveying voyages of His Majesty's Ships Adventure and Beagle between the years 1826 and 1836, describing their examination of the southern shores of South America, and the Beagle's circumnavigation of the globe. Journal and remarks., London: Henry Colburn, p. 488
  17. ^ Rassmann, K.; Tautz, D.; Trillmich, F.; Gliddon, C. (1997). "The micro – evolution of the Galápagos marine iguana Amblyrhynchus cristatus assessed by nuclear and mitochondrial genetic analysis". Molecular Ecology. 6 (5): 437. doi:10.1046/j.1365-294X.1997.00209.x. S2CID 84822976.
  18. ^ Marine Iguana. marinebio.org.
  19. ^ Rassmann, Kornelia (1997). "Evolutionary age of the Galápagos iguanas predates the age of the present Galápagos Islands". Molecular Phylogenetics and Evolution. 7 (2): 158–172. doi:10.1006/mpev.1996.0386. PMID 9126557. Retrieved 18 January 2023.

lisenssi
cc-by-sa-3.0
tekijänoikeus
Wikipedia authors and editors
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia EN

Galapagos land iguana: Brief Summary ( englanti )

tarjonnut wikipedia EN

The Galápagos land iguana (Conolophus subcristatus) is a very large species of lizard in the family Iguanidae. It is one of three species of the genus Conolophus. It is endemic to the Galápagos Islands, in the dry lowlands of the islands of Fernandina, Isabela, Santa Cruz, North Seymour, Baltra, and South Plaza.

lisenssi
cc-by-sa-3.0
tekijänoikeus
Wikipedia authors and editors
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia EN

Conolophus subcristatus ( kastilia )

tarjonnut wikipedia ES

La iguana terrestre de las Galápagos (Conolophus subcristatus) es una especie de reptil de la familia Iguanidae. Es una de las tres especies de Conolophus. Es endémica de las islas Galápagos. Distribuida en las islas isla Isabela, isla Baltra, isla Seymour Norte (introducida desde Baltra), isla Fernandina, isla Plaza Sur, isla Santa Cruz y algunos islotes.[1]​ Se extinguió de isla Santiago, si bien en 2019 ha sido reintroducida en esta isla.[2]

Dieta y longevidad

Las iguanas terrestres son principalmente herbívoras; sin embargo, algunos individuos han demostrado que son carnívoros oportunistas que complementan su dieta con insectos, ciempiés y carroña. Debido a que el agua dulce es escasa en las islas en las que habita, la iguana terrestre de Galápagos obtiene la mayor parte de sus líquidos del cactus nopal que constituye el 80% de su dieta: frutas, flores, almohadillas e incluso las espinas. Durante la temporada de lluvias, beberá de los charcos de agua disponibles y se alimentará con las flores amarillas del género Portulaca. Se estima que la iguana terrestre de Galápagos tiene una vida útil de 50 a 60 años.

Galería

Referencias

  1. a b World Conservation Monitoring Centre (1996). «Conolophus subcristatus». Lista Roja de especies amenazadas de la UICN 2010.2 (en inglés). ISSN 2307-8235. Consultado el Septiembre de 2010.
  2. Trasladan a más de 1.000 iguanas terrestres a una isla de Galápagos para ayudar a su recuperación ecológica

 title=
lisenssi
cc-by-sa-3.0
tekijänoikeus
Autores y editores de Wikipedia
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia ES

Conolophus subcristatus: Brief Summary ( kastilia )

tarjonnut wikipedia ES

La iguana terrestre de las Galápagos (Conolophus subcristatus) es una especie de reptil de la familia Iguanidae. Es una de las tres especies de Conolophus. Es endémica de las islas Galápagos. Distribuida en las islas isla Isabela, isla Baltra, isla Seymour Norte (introducida desde Baltra), isla Fernandina, isla Plaza Sur, isla Santa Cruz y algunos islotes.​ Se extinguió de isla Santiago, si bien en 2019 ha sido reintroducida en esta isla.​

lisenssi
cc-by-sa-3.0
tekijänoikeus
Autores y editores de Wikipedia
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia ES

Conolophus subcristatus ( baski )

tarjonnut wikipedia EU
(RLQ=window.RLQ||[]).push(function(){mw.log.warn("Gadget "ErrefAurrebista" was not loaded. Please migrate it to use ResourceLoader. See u003Chttps://eu.wikipedia.org/wiki/Berezi:Gadgetaku003E.");});
lisenssi
cc-by-sa-3.0
tekijänoikeus
Wikipediako egileak eta editoreak
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia EU

Conolophus subcristatus: Brief Summary ( baski )

tarjonnut wikipedia EU

Conolophus subcristatus Conolophus generoko animalia da. Narrastien barruko Iguanidae familian sailkatuta dago.

lisenssi
cc-by-sa-3.0
tekijänoikeus
Wikipediako egileak eta editoreak
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia EU

Laavaleguaani

tarjonnut wikipedia FI

Laavaleguaani[2] (myös laavalisko, Conolophus subcristatus) on Galápagossaarilla elävä leguaani. Laji oli ennen yleinen, mutta nykyään uhanalainen. Leguaanien elinalueet ovat kuivia minkä vuoksi ne elävät maalla pesissä, jotka suojaavat kuumalta auringonpaisteelta.[3]

Koko ja ulkonäkö

Laavaleguaanit ovat melko suurikokoisia ja raskasrakenteisia; aikuinen leguaani voi olla jopa yli metrin pituinen. Häntä on hieman vartaloa pidempi. Takajalat ovat paksut ja voimakkaat etujalkojen ollessa hieman pienemmät. Jaloissa on pitkät ja voimakkaat kynnet. Väritykseltään leguaanit ovat keltaisia tai ruskeita. Selän puolella juoksee piikikäs harja niskalta alaselkään asti.[3]

Ravinto

Laavaleguaani on kasvinsyöjä. Tärkein ravinnonlähde ovat opuntiakaktukset.[3]

Lisääntyminen

Naaras munii noin 25 pehmeäkuorista munaa pesään kostean hiekan tai lehtikasan alle. Munat kuoriutuvat kolmen tai neljän kuukauden kuluttua.[3][4]

Lähteet

  • World Conservation Monitoring Centre 1996. Conolophus subcristatus. In: IUCN 2006. 2006 IUCN Red List of Threatened Species. Viitattu 26.8.2007. (englanniksi)

Viitteet

  1. World Conservation Monitoring Centre: Conolophus subcristatus IUCN Red List of Threatened Species. Version 2014.1. 1996. International Union for Conservation of Nature, IUCN, Iucnredlist.org. Viitattu 26.6.2014. (englanniksi)
  2. Mikko's phylogeny archive fmnh.helsinki.fi. Viitattu 26.8.2007.
  3. a b c d Bruin, T.: Animal Diversity Web animaldiversity.ummz.umich.edu. Viitattu 26.8.2007. (englanniksi)
  4. Rothman, Robert: Conolophus subcristatus Animal Diversty Web. Viitattu 26.8.2007. (englanniksi)
Tämä matelijoihin liittyvä artikkeli on tynkä. Voit auttaa Wikipediaa laajentamalla artikkelia.
lisenssi
cc-by-sa-3.0
tekijänoikeus
Wikipedian tekijät ja toimittajat
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia FI

Laavaleguaani: Brief Summary

tarjonnut wikipedia FI

Laavaleguaani (myös laavalisko, Conolophus subcristatus) on Galápagossaarilla elävä leguaani. Laji oli ennen yleinen, mutta nykyään uhanalainen. Leguaanien elinalueet ovat kuivia minkä vuoksi ne elävät maalla pesissä, jotka suojaavat kuumalta auringonpaisteelta.

lisenssi
cc-by-sa-3.0
tekijänoikeus
Wikipedian tekijät ja toimittajat
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia FI

Conolophus subcristatus ( ranska )

tarjonnut wikipedia FR

Iguane terrestre des Galapagos

Conolophus subcristatus, l'Iguane terrestre des Galapagos, est une espèce de sauriens de la famille des Iguanidae[1]. C'est l'une des trois espèces du genre Conolophus. Il est endémique des îles Galápagos, notamment des îles Fernandina, Isabela, Santa Cruz, Seymour Nord, Baltra et Plaza[2],[3]. Cette espèce était autrefois extrêmement fréquente, mais les populations ont souffert de l'introduction d'animaux comme les chats, les chiens ou les rats. La population se limite donc aujourd'hui à entre 5 000 et 10 000 individus, et l'espèce est considérée comme vulnérable par l'UICN. Elle fait l'objet de mesures de sauvegarde. La Station Charles-Darwin s'occupe d'élever les iguanes en captivité pour les réintroduire dans des îles où ils ont disparu.

Anatomie et morphologie

 src=
Mâle

Charles Darwin a décrit l'Iguane terrestre des Galapagos comme « un animal affreux, d'un orange jaunâtre dessous, et d'un rouge brunâtre dessus : avec leur angle facial bas ils ont une apparence stupide »[4]. L'Iguane terrestre des Galapagos peut atteindre une taille de 0,9 à 1,5 m pour un poids pouvant atteindre 13 kg, suivant l'île[5],[6]. C'est un animal hétérotherme, qui absorbe la chaleur du soleil en restant se réchauffer au soleil sur des roches volcaniques bien exposées, et se réfugie la nuit dans des terriers pour maintenir une bonne température corporelle[5]. Ces iguanes possèdent une relation symbiotique avec des oiseaux, qui les débarrassent de leurs parasites et tiques, ce qui préserve les iguanes de ces parasites et constitue une source d'alimentation pour les oiseaux[3],[7].

Biologie et écologie

Alimentation

 src=
Les iguanes mangent notamment des feuilles de cactus.

Les iguanes terrestres sont très majoritairement herbivores ; cependant certains individus se montrent carnivores à certaines occasions, complétant leur alimentation avec des insectes, des centipèdes et des charognes[3]. Comme l'eau douce est rare sur les îles dans lesquelles il vit, l'Iguane terrestre des Galapagos tire un maximum d'humidité du cactus du genre Opuntia qui constitue 80 % de son régime alimentaire : fruits, fleurs et même les épines sont consommés[3],[5]. Durant la saison des pluies il boit dans les points d'eau stagnante et mange des fleurs jaunes du genre Portulaca[5],[7].

Cycle de vie

 src=
Iguane se réchauffant au soleil.

L'Iguane terrestre des Galapagos devient sexuellement mature entre 8 et 15 ans, suivant l'île d'où il est originaire[3]. La saison des accouplements varie également beaucoup suivant les îles mais, rapidement après l'accouplement, les femelles − ovipares − migrent vers des zones sableuses pour nicher, pondant entre 2 et 25 œufs dans un terrier peu profond[3]. Les œufs éclosent 90 à 150 jours plus tard[3],[6].

Aux îles Plaza, où les aires de répartition des iguanes marins et terrestres se superposent, les deux peuvent s'hybrider, pour donner des iguanes hybrides aux caractéristiques intermédiaires entre les deux espèces[3]. Les unions les plus probables sont celles entre un mâle iguane marin et une femelle iguane terrestre. En dépit du fait que ces animaux appartiennent à deux genres différents, la progéniture de ces accouplements est viable, mais probablement stérile[3],[8].

On estime que l'Iguane terrestre des Galapagos a une espérance de vie de 50 à 60 ans[3],[6].

Taxinomie

 src=
Iguane en train de s'alimenter.

L'Iguane terrestre des Galapagos a une morphologie et une coloration qui varie légèrement suivant les îles[8]. Il existe deux autres espèces de Conolophus, qui vivent dans la partie ouest de ces îles (C. rosada et C. pallidus), tandis que C. subcristatus vit dans la partie plus centrale[8]. Son nom générique, Conolophus, vient des mots grecs conos (κώνος) signifiant « épineux » et lophos (λόφος) signifiant « crête » ou « plumet », en référence à la crête épineuse qui parcourt son dos. Son épithète spécifique, subcristatus vient du latin sub signifiant « en dessous » et cristatus signifiant « crêté », et fait allusion à la crête épineuse moins grande que chez la plupart des autres iguanes.

On pense que la forme rose de la population des Galapagos est une sous-population génétiquement distincte. Cela signifie qu'il faut désigner cette sous-population comme une espèce à part entière. Des analyses génétiques ont révélé que ces iguanes roses se sont séparés de la population principale de C. subcristatus il y a au moins cinq millions d'années[9],[10].

Relations avec l'Homme

Statut de sauvegarde et population

On estime la population d'iguanes terrestres aux Galapagos entre 5 000 et 10 000[3]. Ces iguanes étaient autrefois si abondants sur l'île Santiago (jadis King James island en anglais) que le naturaliste Charles Darwin a indiqué alors que « (…) quand nous sommes arrivés à James, nous ne pouvions pas trouver un seul endroit sans terriers pour planter une tente »[5],[11]. Dans les années suivantes, des populations entières (incluant tous les iguanes de l'île Santiago) ont disparu, notamment du fait de l'introduction d'animaux non endémiques sur ces îles comme les cochons, les rats, les chats et les chiens qui fouillent les terriers et dévorent les oeufs et les juvéniles[3],[5]. Du fait de sa population en baisse, cette espèce est considérée comme vulnérable dans la liste rouge de l'UICN[2].

Efforts de sauvegarde

 src=
Iguane terrestre des Galapagos jaune à la Station Charles-Darwin
 src=
Iguane terrestre des Galapagos à l'île Seymour Nord.

Depuis le début des années 1990, l'Iguane terrestre des Galapagos a été l'objet d'une active campagne de réintroduction sur l'île Baltra. Ces animaux avaient disparu de cette île depuis 1954, vraisemblablement éradiqués par les soldats de la base américaine de l'île, qui tiraient sur les iguanes « pour s'amuser »[3],[7]. Au début des années 1930, William Randolph Hearst a déplacé une population d'iguanes de Baltra vers l'île Seymour Nord, plus petite, située à une centaine de mètres au nord de Baltra : il ne comprenait pas pourquoi les iguanes étaient absents de cette île. Cette population a survécu, et a constitué le cheptel d'iguanes reproducteurs du programme d'élevage en captivité de la Station Charles-Darwin, qui a réintroduit avec succès l'espèce à Baltra et dans de nombreuses autres zones[3]. Les touristes voient aujourd'hui fréquemment des iguanes qui traversent la route ou à proximité de l'aéroport de Baltra.

Publication originale

  • Gray, 1831 : Description of a new species of Amblyrhynchus of Mr. Bell, in the British Museum. Zoological Miscellany, vol. 1, p. 6 (texte intégral).

Notes et références

  1. Reptarium Reptile Database, consulté lors d'une mise à jour du lien externe
  2. a et b UICN, consulté lors d'une mise à jour du lien externe
  3. a b c d e f g h i j k l m et n Freda, « Land iguanas » , sur Charles Darwin Research Station Fact Sheet, Charles Darwin Foundation for the Galapagos Islands, 2006 (consulté le 14 octobre 2007)
  4. Charles Darwin, The Voyage of the Beagle : Charles Darwin's Journal of Researches, New York, Penguin Classics, 1989, 432 p. (ISBN 978-0-14-043268-8)
  5. a b c d e et f Barbara Rogers, Galapagos, New York, Mallard Press, 1990, 144 p. (ISBN 978-0-7924-5192-1)
  6. a b et c Ellen Rosenthal, « Days and nights of the iguana: in the Galapagos, a devoted pair work to save land iguanas », Animals,‎ 1997 (lire en ligne, consulté le 16 octobre 2007)
  7. a b et c John Kricher, Galapagos : A Natural History, New Jersey, Princeton University Press, 2006, 221 p. (ISBN 978-0-691-12633-3, lire en ligne)
  8. a b et c Kornelia Rassmann, Melanie Markmann, Fritz Trillmich et Diethard Tautz, Iguanas : Biology and Conservation, Californie, University of California Press, 2004, 356 p. (ISBN 978-0-520-23854-1, lire en ligne), « Tracing the Evolution of the Galapagos Iguanas », p. 71–83
  9. (en) Alexis Madrigal, « Pink Iguana That Darwin Missed Holds Evolutionary Surprise », sur Wired Science, Wired, 5 janvier 2009 (consulté le 6 janvier 2009).
  10. Gabriele Gentile, Anna Fabiani, Cruz Marquez, Howard L. Snell, Heidi M. Snell, Washington Tapia et Valerio Sbordonia, « An overlooked pink species of land iguana in the Galapagos », Proceedings of the National Academy of Sciences, National Academy of Sciences, vol. 106, no 2,‎ 2009, p. 507 (PMID , PMCID , DOI )
  11. Charles Darwin, Narrative of the surveying voyages of His Majesty's Ships Adventure and Beagle between the years 1826 and 1836, describing their examination of the southern shores of South America, and the Beagle's circumnavigation of the globe. Journal and remarks., Londres, Henry Colburn, 1839, 488 p.
lisenssi
cc-by-sa-3.0
tekijänoikeus
Auteurs et éditeurs de Wikipedia
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia FR

Conolophus subcristatus: Brief Summary ( ranska )

tarjonnut wikipedia FR

Iguane terrestre des Galapagos

Conolophus subcristatus, l'Iguane terrestre des Galapagos, est une espèce de sauriens de la famille des Iguanidae. C'est l'une des trois espèces du genre Conolophus. Il est endémique des îles Galápagos, notamment des îles Fernandina, Isabela, Santa Cruz, Seymour Nord, Baltra et Plaza,. Cette espèce était autrefois extrêmement fréquente, mais les populations ont souffert de l'introduction d'animaux comme les chats, les chiens ou les rats. La population se limite donc aujourd'hui à entre 5 000 et 10 000 individus, et l'espèce est considérée comme vulnérable par l'UICN. Elle fait l'objet de mesures de sauvegarde. La Station Charles-Darwin s'occupe d'élever les iguanes en captivité pour les réintroduire dans des îles où ils ont disparu.

lisenssi
cc-by-sa-3.0
tekijänoikeus
Auteurs et éditeurs de Wikipedia
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia FR

Conolophus subcristatus ( Italia )

tarjonnut wikipedia IT

Il Conolophus subcristatus, noto anche come iguana di terra o iguana terrestre delle Galápagos è un rettile endemico delle isole Galápagos.

Descrizione

La lunghezza di quest'iguana varia tra uno e due metri, compresa la coda, mentre invece il peso va da 8 a 15 kg. Ha una pupilla rotonda, come altri rettili notturni e palpebre molto ben sviluppate. Possiede un senso dell'udito ben sviluppato ed organi uditivi completi, laddove i serpenti non ne hanno. La bocca consente all'iguana di cibarsi di cactus, una tra le poche fonti alimentari disponibili sulle isole in cui vive. I denti sono posti nel lato interno delle mandibole, il che rende C. subcristatus diverso dalle iguane che vivono in altri continenti. La lingua è spessa e larga; le zampe sono fornite di 5 dita ognuna. Sul dorso c'è una cresta spinosa che va via via decrescendo con il progressivo avvicinarsi alla coda, che non gode di autotomia. Ciò è dovuto alla mancanza di superpredatori ed altri carnivori in grado di uccidere esemplari di iguana di terra e, pertanto, la capacità rigenerativa di tale appendice è diminuita fino a scomparire quasi del tutto. A dimostrazione di questo fatto, osservazioni condotte su 200 esemplari hanno portato alla luce che solo due fra loro erano capaci di rigenerarne buona parte. Ogni individuo è tuttavia è capace di farla ricrescere, anche in misura minima. La colorazione assunta da C. subcristatus può variare dal marroncino smorto al giallo acceso. Le squame crescono verso l'alto e successivamente verso l'esterno e vengono sostituite regolarmente da altre nuove. Poiché la pelle è impermeabilizzata, quest'iguana sopravvive senza problemi all'aridità ed alla secchezza del suo habitat.

Biologia

Alimentazione

Si nutre di piante, specificamente di cactus del tipo nopal ed i loro fiori. Nonostante siano coriacei e spinosi non causano alcun problema all'iguana durante il processo digestivo.

Comportamento e riproduzione

L'indole di quest'animale è mite e quieta: durante il giorno possono essere ammirate mentre vanno in cerca di cibo o fanno i loro bagni di sole. L'utilità di questi risiede nel fatto che, trattandosi di una specie eteroterma, l'iguana terrestre, come del resto la maggior parte dei rettili, ha bisogno di fonti di calore esterne per avviare le sue funzioni vitali fondamentali ed il suo metabolismo. Quando la temperatura diventa talmente torrida da non essere più sopportabile, C. subcristatus cerca rifugio nei buchi scavati nel terreno. La natura placida di questi sauri subisce un radicale cambiamento durante la stagione degli amori: i maschi difendono strenuamente il loro territorio, ricco di cavità che esercitano una forte attrazione sulle femmine, là infatti verranno deposte le uova, ma assenza di rientranze, la vegetazione offre una valida alternativa. Ogni maschio, qualora riscontri la presenza di un intruso lo insegue per metterlo in fuga, solo di rado si ricorre alla lotta. Il corteggiamento appare veemente e si manifesta con piccoli inseguimenti tra le fessure rocciose. L'incubazione dura almeno tre mesi e dopo la schiusa, i piccoli passano un periodo di tempo indeterminato nel luogo in cui sono nati, per poi abbandonarlo quando si sentono sicuri

Predatori

Normalmente l'iguana terrestre non avrebbe predatori, eccezion fatta per la poiana delle Galápagos che occasionalmente si ciba dei piccoli, però le specie aliene introdotte dagli uomini arrivati nelle isole, vale a dire cani, gatti e ratti rappresentano una seria minaccia per la popolazione di C. subcristatus.

Curiosità

Accanto alla ben più diffusa C. subcristatus c'è anche la specie C. pallidus, chiamata così per via dei suoi colori meno appariscenti. La sua popolazione è più esigua ed inoltre vive unicamente nell'Isola di Santa Fe.

Galleria d'immagini

Note

  1. By DerUlukai - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=73934698
  2. By RuyCalderon - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=42261297

Bibliografia

 title=
lisenssi
cc-by-sa-3.0
tekijänoikeus
Autori e redattori di Wikipedia
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia IT

Conolophus subcristatus: Brief Summary ( Italia )

tarjonnut wikipedia IT

Il Conolophus subcristatus, noto anche come iguana di terra o iguana terrestre delle Galápagos è un rettile endemico delle isole Galápagos.

lisenssi
cc-by-sa-3.0
tekijänoikeus
Autori e redattori di Wikipedia
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia IT

Legwan galapagoski ( puola )

tarjonnut wikipedia POL
Commons Multimedia w Wikimedia Commons

Legwan galapagoski, legwan z Galapagos, legwan lądowy, konolof (Conolophus subcristatus) – gatunek dużej jaszczurki z rodziny legwanowatych (Iguanidae). Oprócz gatunku Conolophus subcristatus występującego na 6 wyspach archipelagu Galapagos wyróżnia się dwa inne gatunki z rodzaju ConolophusConolophus pallidus, występujący tylko na wyspie Santa Fe oraz Conolophus marthae, endemiczny dla wyspy Isabela. Analizy morfologiczne i genetyczne sugerują, że niektóre populacje legwana galapagoskiego mogą zasługiwać na status odrębnych gatunków[2].

Opis
Masywnie zbudowany, ciemno-żółto ubarwiony, na karku ma niewielki grzebień skórny. Sprawia wrażenie ociężałego.
Rozmiary
Długość ciała do ok. 125 cm
Masa ciała samców do 13 kg
Biotop
Żyje na terenach suchych w głębi lądu z dala od wybrzeży morskich.
Pokarm
Wyłącznie rośliny rosnące nisko nad ziemią także kaktusy, które zjada wraz z kolcami, również opadłe owoce. Soczyste rośliny dostarczają im wilgoci, której potrzebują podczas suchych okresów.
Zachowanie
Aby uniknąć gorącego, równikowego słońca południa szukają cienia pod kaktusami lub skałami. Wieczorem śpią w jamach wykopanych w gruncie, aby jak najdłużej utrzymać ciepło ciała. Legwany lądowe żyją w symbiozie z ziębami Darwina – podnoszą się na nogach i pozwalają małym ptakom usuwać kleszcze z ich ciał.
Rozmnażanie
Dojrzałość osiągają pomiędzy 8 a 15 rokiem życia. Samce obierają sobie terytorium, którego zaciekle bronią przed innymi samcami. Na swoim terytorium mają kilka samic. Samice wędrują do odpowiednich miejsc, by złożyć od 2 do 25 jaj w jamie wykopanej w piaszczystej glebie. Samica przez krótki czas broni jamy przed innymi samicami chcącymi złożyć jaja w tym samym miejscu. Młode legwany wylęgają się 3-4 miesiące później i dopiero po tygodniu wychodzą z gniazd. Jeśli przeżywają pierwsze, trudne lata życia z powodu braku pokarmu lub drapieżników mogą żyć dłużej niż 50 lat.
Występowanie
Gatunek endemiczny zasiedlający tylko wyspy Galapagos.

Przypisy

  1. Conolophus subcristatus. Czerwona księga gatunków zagrożonych (IUCN Red List of Threatened Species) (ang.).
  2. Gabriele Gentile, Howard L. Snell. Conolophus marthae sp.nov. (Squamata, Iguanidae), a new species of land iguana from the Galápagos archipelago. „Zootaxa”. 2201, s. 1–10, 2009 (ang.).

Bibliografia

  1. Hanna Dobrowolska: Gady. Warszawa: Państwowe Wydaw. Naukowe, 1981. ISBN 83-01-00957-8.
  2. Włodzimierz Juszczyk: Gady i płazy. Warszawa: Wiedza Powszechna, 1986. ISBN 83-214-0464-2.
  3. Zwierzęta: encyklopedia ilustrowana. Warszawa: Wydawnictwo Naukowe PWN, 2005, s. 372, 373. ISBN 83-01-14344-4.
p d e
Iguania Rodziny Legwan zielony1.jpg
lisenssi
cc-by-sa-3.0
tekijänoikeus
Autorzy i redaktorzy Wikipedii
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia POL

Legwan galapagoski: Brief Summary ( puola )

tarjonnut wikipedia POL

Legwan galapagoski, legwan z Galapagos, legwan lądowy, konolof (Conolophus subcristatus) – gatunek dużej jaszczurki z rodziny legwanowatych (Iguanidae). Oprócz gatunku Conolophus subcristatus występującego na 6 wyspach archipelagu Galapagos wyróżnia się dwa inne gatunki z rodzaju ConolophusConolophus pallidus, występujący tylko na wyspie Santa Fe oraz Conolophus marthae, endemiczny dla wyspy Isabela. Analizy morfologiczne i genetyczne sugerują, że niektóre populacje legwana galapagoskiego mogą zasługiwać na status odrębnych gatunków.

Opis Masywnie zbudowany, ciemno-żółto ubarwiony, na karku ma niewielki grzebień skórny. Sprawia wrażenie ociężałego. Rozmiary Długość ciała do ok. 125 cm
Masa ciała samców do 13 kg Biotop Żyje na terenach suchych w głębi lądu z dala od wybrzeży morskich. Pokarm Wyłącznie rośliny rosnące nisko nad ziemią także kaktusy, które zjada wraz z kolcami, również opadłe owoce. Soczyste rośliny dostarczają im wilgoci, której potrzebują podczas suchych okresów. Zachowanie Aby uniknąć gorącego, równikowego słońca południa szukają cienia pod kaktusami lub skałami. Wieczorem śpią w jamach wykopanych w gruncie, aby jak najdłużej utrzymać ciepło ciała. Legwany lądowe żyją w symbiozie z ziębami Darwina – podnoszą się na nogach i pozwalają małym ptakom usuwać kleszcze z ich ciał. Rozmnażanie Dojrzałość osiągają pomiędzy 8 a 15 rokiem życia. Samce obierają sobie terytorium, którego zaciekle bronią przed innymi samcami. Na swoim terytorium mają kilka samic. Samice wędrują do odpowiednich miejsc, by złożyć od 2 do 25 jaj w jamie wykopanej w piaszczystej glebie. Samica przez krótki czas broni jamy przed innymi samicami chcącymi złożyć jaja w tym samym miejscu. Młode legwany wylęgają się 3-4 miesiące później i dopiero po tygodniu wychodzą z gniazd. Jeśli przeżywają pierwsze, trudne lata życia z powodu braku pokarmu lub drapieżników mogą żyć dłużej niż 50 lat. Występowanie Gatunek endemiczny zasiedlający tylko wyspy Galapagos.
lisenssi
cc-by-sa-3.0
tekijänoikeus
Autorzy i redaktorzy Wikipedii
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia POL

Iguana-terrestre-das-galápagos ( portugali )

tarjonnut wikipedia PT

A iguana-amarela ou iguana-terrestre-das-Galápagos (Conolophus subcristatus) é uma espécie de iguana que habita a Ilha de Galápagos.[1]

Referências

  1. a b Kumar, K., Gentile, G. & Grant, T.D. (2020). Conolophus subcristatus (em inglês). IUCN 2020. Lista Vermelha de Espécies Ameaçadas da IUCN de 2020 Versão e.T5240A3014082. doi:10.2305/IUCN.UK.2020-2.RLTS.T5240A3014082.en Página visitada em 28 de outubro de 2021.

 title=
lisenssi
cc-by-sa-3.0
tekijänoikeus
Autores e editores de Wikipedia
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia PT

Iguana-terrestre-das-galápagos: Brief Summary ( portugali )

tarjonnut wikipedia PT

A iguana-amarela ou iguana-terrestre-das-Galápagos (Conolophus subcristatus) é uma espécie de iguana que habita a Ilha de Galápagos.

lisenssi
cc-by-sa-3.0
tekijänoikeus
Autores e editores de Wikipedia
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia PT

Galapagos kara iguanası ( turkki )

tarjonnut wikipedia TR

Galapagos kara iguanası (Conolophus subcristatus), Iguanidae familyasına ait, pullu bir sürüngen türü. Conolophus cinsine mensup üç türden biridir. Öncelikle Fernandina, Isabela, Santa Cruz, North Seymour, Baltra ve South Plaza adaları olmak üzere Galapagos Adalarına özgü endemik canlılardır.

Taksonomi

Galapagos kara iguanası bölgedeki çeşitli adalarda farklı morfolojik ve renksel değişiklikler göstermektedir. Conolophus cinsinin kapsadığı üç türden iki tanesi olan C. rosada ve C. pallidus adaların batı bölümünde, son tür ise merkezi kısımlarda yaşamını sürdürmektedir (C. subcristatus). Genel adıyla Conolophus ismi, canlının sırtı boyunca yer alan dikenli tepeleri ifade eden iki Yunanca kelimeden türetilmiştir; dikenli anlamında kullanılan conos (κώνος) ve sorguç veya tüy anlamına gelen lophos (λοφος). Tür adı olan (Subcristatus) ise Latince daha küçük veya az anlamına gelen sub ve "tepeli, ibikli, sorguçlu" anlamlarıa gelen cristatus isminden türetilmiştir. Bu ifade Iguanidae familyasında pek sık görülmediği üzere, sırt boyunca "kısa" olan sorguçları vurgular.

Anatomi ve morfoloji

Charles Darwin Galapagos kara iguanalarından "alt kısmı sarımsı-turuncu ve üst kısmı kahverengimsi-kırmızı renkte olan sersem bir görünüme sahip çirkin hayvanlar" olarak bahseder. Yaşadıkları adaya bağlı olarak Galapagos kara iguanaları 1-1,5 metre arası uzunluğa ve 12 kiloya kadar ağırlığa ulaşırlar. Soğukkanlı canlılar olmaları nedeniyle gün içinde volkanik kayalar üzerinde güneşlenerek sıcaklığı emerler ve gece vakti oyuklarında uyurken vücut ısılarını bu şekilde muhafaza etmiş olurlar. Kuşlar ile birlikte simbiyotik bir yaşama sahiptirler; kuşlar iguanalara yapışmış parazit ve keneleri yiyerek beslenirken aynı zamanda iguanalar da üzerindeki zararlılardan arınmaktadır.

Beslenme Şekli ve Ömrü

 src=
Beslenme sırasında
 src=
Düşmüş kaktüs parçasıyla beslenirken

Kara iguanaları öncelikli olarak otçullardır ancak bazı bireyleri böcekler, kırkayaklar ve leşleri de tüketme yoluyla beslenmelerini tamamlayarak fırsatçı etçiller olduklarını göstermektedirler. Bunun sebebi tatlı suyun ada üzerinde çok kıt olmasıdır. Galapagos kara iguanası nemliliğinin büyük bir kısmını, beslenmesinin %80'ini oluşturan dikenli armut kaktüsünün (Kaynanadili) meyve, çiçek ve hatta dikenlerinden karşılamaktadır. Yağışlı mevsimler boyunca yerdeki su birikintilerinden ve Portulaca cinsi bitkilerin sarı çiçekleri üzerinde toplanan suları tüketerek tam bir bolluk yaşarlar. Galapagos kara iguanalarının tahmini ömrü 50-60 yıldır.

Üreme

 src=
Güneşlenme sırasında

Galapagos kara iguanaları yetiştikleri adaya bağlı olarak 8-15 yıl içerisinde cinsel açıdan olgun bir hale gelirler. Çiftleşme sezonu adalar arasında farklılık gösterir, çiftleşmeden kısa bir sonra dişi iguana yuva yapmak için kumlu alana göç eder. 45 santimetre derinliğindeki bir oyuk içerisine 2-25 adet arası yumurta bırakır. 90-125 gün aralığındaki bir süreçten sonra yumurtalar çatlamaya başlar ve yavrular dışarı çıkar.

Deniz ve kara iguanalarının yaşam alanlarının çakıştığı South Plaza adasında, bazı zamanlar bu iki farklı türün karşılaşması ve çiftleşmesi, iguanaların kendi türlerine has özelliklerin karışmasına ve ortaya hibrit iguana adı verilen bir türün oluşmasına sebep olur. Bu çiftleşme genellikle erkek deniz iguanası ve dişi kara iguanası arasında gerçekleşme eğilimindedir. Farklı cinslerden farklı türler olmalarına ve uzun ayrılık zamanlarına rağmen yavrular yaşayabilirler ve genellikle kısır olurlar.

Nüfus

Galapagos sınırları içerisinde 5.000 ile 10.000 arası kara iguanasının geçmişte yaşadığı tahmin edilmektedir. Charles Darwin Santiago adasındayken iguana sayısı çok fazlaydı ve o zamanlar henüz King James Island adıyla bilinen ada hakkında Charles düşüncelerini şöyle belirtmişti "...sayıları hakkında bundan daha etkili bir kanıt veremem. Santiago adasından ayrıldığımız dönemlerde çadırımızı kurabilmek için oyuk açılmamamış tek bir alan bulamadığımız anlar olmuştu."

Her nasılsa, 1800'lü yıllarda balina avcıları ve yerleşimciler Galapagos'u ziyeret etmeye başladıklarında yanlarında keçi, domuz, kedi ve köpek gibi hayvanları getirmeye başladılar. Zamanla bu hayvanlar sahiplerinden kaçtılar veya adaya terk edildiler. Bunun neticesinde aç kalan kediler yavru iguanaları, köpekler yetişkin bireyleri avlamaya başladılar. Keçiler ise iguanaların besin olarak tükettiği bütün bitkileri yediler. Günümüzde Santiago adasındaki -zamanında Darwin'in notlarında bahsettiği- bol miktradaki iguanaların ve adada yaşayan diğer bütün hayvanların nesli tükenmiştir.

Kurtarma Çalışmaları

 src=
Erkek
 src=
Sarı renkli kara iguanası (Charles Darwin Araştırma İstasyonu)

1990'ların başında Galapagos kara iguanaları, Baltra adasında bu canlıları yeniden üretme kampanyasının bir konusuydu. İddiaya göre 1954 yılında Baltra adasında konuşlu askerler tarafından eğlence amaçlı vurulmaları sonucu bu canlıların sayıları azalmış ve soyları tükenmişti. Her nasılsa 1930'ların başında William Randolph Hearst kara iguanası popülasyonunun bir kısmının yerini Baltra adasından, adanın birkaç yüz metre kuzeyindeki North Seymour adasına, neden o adada iguana bulunmadığını anlayamamasından ötürü ve iguanaları yaymak için taşıyarak değiştirmişti. Hearst'in yerini değiştirdiği iguanalar hayatta kalmayı başardı ve Charles Darwin Araştırma İstasyonu'nda "nesli tükenmekte olan hayvanların korunaklı bölgelerde yetiştirilmesi programı"nda damızlık olarak kullanıldılar ve sonucunda başarıya ulaşılarak Baltra ve diğer yerler için yeniden bu canlıların türetilmesinin önü açılmıştır. Ziyaretçiler bugün sıklıkla Baltra Havaalanı pist yolunun her iki tarafında bu iguanalara rastlamaktadırlar.

Kaynakça

  • World Conservation Monitoring Centre (1996). Conolophus subcristatus. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 8 September 2007.
  • Freda (2006). "Land iguanas". Charles Darwin Research Station Fact Sheet. Charles Darwin Foundation for the Galapagos Islands. Archived from the original on 2007-06-06. Retrieved 2007-10-14.
  • Rassmann, Kornelia; Markmann, Melanie; Trillmich, Fritz; Tautz, Diethard (2004), "Tracing the Evolution of the Galapagos Iguanas", Iguanas: Biology and Conservation (California: University of California Press): 71–83, ISBN 978-0-520-23854-1
  • Darwin, Charles (1989), The Voyage of the Beagle: Charles Darwin's Journal of Researches, New York: Penguin Classics, p. 401, ISBN 978-0-14-043268-8
  • Rogers, Barbara (1990), Galapagos, New York: Mallard Press, p. 51, ISBN 978-0-7924-5192-1
  • Rosenthal, Ellen (1997), "Days and nights of the iguana: in the Galapagos, a devoted pair work to save land iguanas", Animals, retrieved 2007-10-16.
  • Kricher, John (2006), Galapagos: A Natural History, New Jersey: Princeton University Press, pp. 9,51,91,200, ISBN 978-0-691-12633-3
  • Darwin (1839), Narrative of the surveying voyages of His Majesty's Ships Adventure and Beagle between the years 1826 and 1836, describing their examination of the southern shores of South America, and the Beagle's circumnavigation of the globe. Journal and remarks., London: Henry Colburn, p. 488
  • Madrigal, Alexis (2009-01-05). "Pink Iguana That Darwin Missed Holds Evolutionary Surprise". Wired Science. Wired. Retrieved 2009-01-06.
  • Gentile, Gabriele; Anna Fabiani, Cruz Marquez, Howard L. Snell, Heidi M. Snell, Washington Tapia, and Valerio Sbordonia (2009), "An overlooked pink species of land iguana in the Galapagos", Proceedings of the National Academy of Sciences (National Academy of Sciences) 106 (2): 507, doi:10.1073/pnas.0806339106, PMC 2626733, PMID 19124773.
  • İngilizce Wikipedia sürümünün kompozisyon düzeni.
 src= Wikimedia Commons'ta Galapagos kara iguanası ile ilgili medyaları bulabilirsiniz.
lisenssi
cc-by-sa-3.0
tekijänoikeus
Wikipedia yazarları ve editörleri
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia TR

Galapagos kara iguanası: Brief Summary ( turkki )

tarjonnut wikipedia TR

Galapagos kara iguanası (Conolophus subcristatus), Iguanidae familyasına ait, pullu bir sürüngen türü. Conolophus cinsine mensup üç türden biridir. Öncelikle Fernandina, Isabela, Santa Cruz, North Seymour, Baltra ve South Plaza adaları olmak üzere Galapagos Adalarına özgü endemik canlılardır.

lisenssi
cc-by-sa-3.0
tekijänoikeus
Wikipedia yazarları ve editörleri
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia TR

Cự đà đất Galapagos ( vietnam )

tarjonnut wikipedia VI

Cự đà đất Galapagos (Conolophus subcristatus) là một loài thằn lằn trong họ Iguanidae. Loài này được Gray mô tả khoa học đầu tiên năm 1831.[2]

Đây là loài đặc hữu của quần đảo Galapagos, chủ yếu là các đảo Fernandina, Isabela, Santa Cruz, Bắc Seymour, Baltra, và Nam Plaza.

Hình ảnh

Tham khảo

  1. ^ World Conservation Monitoring Centre (1996). Conolophus subcristatus. Sách đỏ 2006. IUCN 2006. Truy cập ngày 8 tháng 9 năm 2007.
  2. ^ Conolophus subcristatus. The Reptile Database. Truy cập ngày 31 tháng 5 năm 2013.
 src= Wikimedia Commons có thư viện hình ảnh và phương tiện truyền tải về Cự đà đất Galapagos


Hình tượng sơ khai Bài viết liên quan đến bộ bò sát có vảy này vẫn còn sơ khai. Bạn có thể giúp Wikipedia bằng cách mở rộng nội dung để bài được hoàn chỉnh hơn.
lisenssi
cc-by-sa-3.0
tekijänoikeus
Wikipedia tác giả và biên tập viên
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia VI

Cự đà đất Galapagos: Brief Summary ( vietnam )

tarjonnut wikipedia VI

Cự đà đất Galapagos (Conolophus subcristatus) là một loài thằn lằn trong họ Iguanidae. Loài này được Gray mô tả khoa học đầu tiên năm 1831.

Đây là loài đặc hữu của quần đảo Galapagos, chủ yếu là các đảo Fernandina, Isabela, Santa Cruz, Bắc Seymour, Baltra, và Nam Plaza.

lisenssi
cc-by-sa-3.0
tekijänoikeus
Wikipedia tác giả và biên tập viên
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia VI

加拉巴哥陸鬣蜥 ( kiina )

tarjonnut wikipedia 中文维基百科
二名法 Conolophus subcristatus
(Gray, 1831)

加拉帕戈斯陸鬣蜥(學名:Conolophus subcristatus)是一種屬於美洲鬣蜥科蜥蜴,也是陸鬣蜥屬兩個物種的其中之一。為生存於加拉帕戈斯群島特有種,主要棲息於其中的費爾南迪納島(Isla Fernandina)、伊莎貝拉島(Isla Isabela)、圣克鲁兹岛(Isla Santa Cruz )、北西摩島(Isla Seymour Norte)、小西班牙島(Isla Española)以及南普拉薩島(Isla Plaza Sur)[1][2]

分類學與型態學

棲息於不同島嶼上的加拉帕戈斯陸鬣蜥族群,在型態與體表色彩上有所差異[3]。其屬名「Conolophus」是源自希臘文的「cono」(多刺的)與「loph」(背脊),意指其排列於背上的尖刺。而種小名subcristatus」則是源自拉丁文中的「sub」(低矮的)與「cristatus」(背脊),意指這種鬣蜥背上的尖刺比起其他種類的鬣蜥更短。

19世紀時,到此探險的查爾斯·達爾文曾對加拉帕戈斯陸鬣蜥有如此的描述:「難看的動物,下半部呈橘黃色,上半部呈紅褐色,由於低面角(low facial angle)的緣故,使牠們的外表看起來格外地愚蠢。」[4][5]這種鬣蜥的身長約3到5呎(feet),體重最重25磅,依其所棲息的島嶼而有所差異[6][7]

習性與壽命

由於是變溫動物,因此加拉巴哥陸鬣蜥白天時會停留在火山岩上曬太陽;到了晚上則到洞穴中睡覺,以維持體溫[6]。除此之外,當地某些鳥類會將這種鬣蜥身上的寄生蟲蝨子吃掉,兩者之間形成一種共生關係[2][8]

加拉帕戈斯陸鬣蜥通常為草食性,不過有些個體具有機會性質的肉食行為,會補充一些昆蟲蜈蚣腐肉[2]。由於淡水在群島上相當地缺乏,因此加拉巴哥陸鬣蜥主要是從當地的仙人掌(prickly-pear cactus)獲取水分,而仙人掌的果實、花、莖甚至尖刺,構成了這些鬣蜥80%的食物來源[6][2]。只有在雨季時,牠們才能找到水池,並以一些齒莧屬Portulaca)植物的花為食[6][8]

根據估計,加拉帕戈斯陸鬣蜥約有60年的壽命[2][7]

繁殖

加拉帕戈斯陸鬣蜥的性成熟大約發生於出生後8到15年之間,差異出現於不同島嶼上的族群[2],而交配期也同樣依島嶼而定。在交配過後,雌性鬣蜥會遷移到沙地築巢,並在一個深約18吋的凹洞中產下2到25顆卵[2],下蛋時間約在90天到120天後[2][7]

在South Plaza島上,加拉帕戈斯陸鬣蜥與加拉巴哥海鬣蜥Amblyrhynchus cristatus,或稱海鬣蜥)的生活領域發生重疊,而兩種動物因而發生種間雜交,產生一些同時含有兩物種特徵的後代[2]。這些雜交產生的個體長得像是雄性海鬣蜥與雌性陸鬣蜥的合體。雖然親代是來自兩個不同的物種,但仍可存活,只是不具繁殖能力[2][3]

族群

根據估計,大約有5000到10000隻的加拉帕戈斯陸鬣蜥棲息於群島上[2]。在查爾斯·達爾文來到此地探險時,群島中的聖地牙哥島(Santiago Island)上還有數量相當充裕的加拉帕戈斯陸鬣蜥。當時這座島稱為「詹姆士國王島」(King James Island),達爾文的紀錄如下:「……當我們停留在島上時,我們找不到一個位置,是可以讓我們搭營,而沒有牠們的巢穴的。」[9][6][10]。不過到了今天,聖地牙哥島上的所有加拉帕戈斯陸鬣蜥族群已經完全消失,取而代之的是豬、老鼠、貓與狗[2][6]

 src=
北西摩島上的陸鬣蜥。

數量減少與復育

原本由人類所帶來,並在此野化的動物,是加拉帕戈斯陸鬣蜥最主要的生存威脅[2]。野狗和野貓會攻擊這些鬣蜥,並破壞牠們的巢穴。而且由於數百萬年來加拉巴哥群島的孤立,鬣蜥們並未發展出逃離掠食者的能力[7][2]。野豬在覓食的過程中,也會破壞鬣蜥巢穴,甚至吃掉產於其中的卵。此種現象普遍發生於塞羅阿蘇爾火山(Cerro Azul volcano)地區以及伊莎貝拉島上。此外,引進此地的山羊也與鬣蜥在食物及水的來源上發生競爭。山羊的覓食行為連帶也影響了加拉巴哥鷹Buteo galapagoensis)的生存[11]

有一個將加拉帕戈斯陸鬣蜥重新引入巴爾特拉島(Baltra Island)的計畫。原來居住在這座島上的陸鬣蜥遭過去駐紮於此的士兵當成射擊標靶來作娛樂,因而在1954年完全滅絕[2][8]。不過在1930年代,美國報紙發行人威廉·藍道夫·赫斯特曾將這座島上的陸鬣蜥帶到幾百公尺遠的北西摩島上(而且當時北西摩島還沒有鬣蜥生存,原因不明),這些陸鬣蜥因此成為查爾斯·達爾文研究站(Charles Darwin Research Station)的保留品系,用來重新引入巴爾特拉島和其他區域[2]

參考文獻

  1. ^ Conolophus subcristatus. IUCN Red List of Threatened Species 2006. International Union for Conservation of Nature. 1996.
  2. ^ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 2.15 Freda. Land iguanas (PDF). Charles Darwin Research Station Fact Sheet. Charles Darwin Foundation for the Galapagos Islands. 2006 [2007-10-14]. (原始内容 (PDF)存档于2007-06-06).
  3. ^ 3.0 3.1 Rassmann, Kornelia; Markmann, Melanie; Trillmich, Fritz; Tautz, Diethard, Tracing the Evolution of the Galapagos Iguanas, Iguanas: Biology and Conservation (California: University of California Press), 2004: 71–83, ISBN 9780520238541
  4. ^ 原文:"ugly animals, of a yellowish orange beneath, and of a brownish-red colour above: from their low facial angle they have a singularly stupid appearance."
  5. ^ Darwin, Charles, The Voyage of the Beagle: Charles Darwin's Journal of Researches, New York: Penguin Classics: 401, 1989, ISBN 9780140432688
  6. ^ 6.0 6.1 6.2 6.3 6.4 6.5 Rogers, Barbara, Galapagos, New York: Mallard Press: 51, 1990, ISBN 9780792451921
  7. ^ 7.0 7.1 7.2 7.3 Rosenthal, Ellen. Days and nights of the iguana: in the Galapagos, a devoted pair work to save land iguanas. Animals. 1997 [2007-10-16].
  8. ^ 8.0 8.1 8.2 Kricher, John, Galapagos: A Natural History, New Jersey: Princeton University Press: 9,51,91,200, 2006, ISBN 9780691126333
  9. ^ 原文:"...when we were left at James, we could not for some time find a spot free from their burrows on which to pitch our single tent"
  10. ^ Darwin, Charles, Narrative of the surveying voyages of His Majesty's Ships Adventure and Beagle between the years 1826 and 1836, describing their examination of the southern shores of South America, and the Beagle's circumnavigation of the globe. Journal and remarks., London: Henry Colburn: 488, 1839
  11. ^ Knapp, Charles R.; Hudson, Richard, Translocation Strategies as a Conservation Tool for West Indian Iguanas, Iguanas: Biology and Conservation (University of California Press), 2004: 199–204, ISBN 9780520238541


 src=
科隆群岛
科隆群岛


lisenssi
cc-by-sa-3.0
tekijänoikeus
维基百科作者和编辑
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia 中文维基百科

加拉巴哥陸鬣蜥: Brief Summary ( kiina )

tarjonnut wikipedia 中文维基百科

加拉帕戈斯陸鬣蜥(學名:Conolophus subcristatus)是一種屬於美洲鬣蜥科蜥蜴,也是陸鬣蜥屬兩個物種的其中之一。為生存於加拉帕戈斯群島特有種,主要棲息於其中的費爾南迪納島(Isla Fernandina)、伊莎貝拉島(Isla Isabela)、圣克鲁兹岛(Isla Santa Cruz )、北西摩島(Isla Seymour Norte)、小西班牙島(Isla Española)以及南普拉薩島(Isla Plaza Sur)。

lisenssi
cc-by-sa-3.0
tekijänoikeus
维基百科作者和编辑
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia 中文维基百科

ガラパゴスリクイグアナ ( Japani )

tarjonnut wikipedia 日本語
ガラパゴスリクイグアナ ガラパゴスリクイグアナ
ガラパゴスリクイグアナ
Conolophus subcristatus
保全状況評価[1][2] VULNERABLE
(IUCN Red List Ver.2.3 (1994))
Status iucn2.3 VU.svgワシントン条約附属書II 分類 : 動物界 Animalia : 脊索動物門 Chordata 亜門 : 脊椎動物亜門 Vertebrata : 爬虫綱 Reptilia : 有鱗目 Squamata 亜目 : トカゲ亜目 Sauria 下目 : イグアナ下目 Iguania : イグアナ科 Iguanidae 亜科 : イグアナ亜科 Iguaninae : リクイグアナ属 Conolophus : ガラパゴスリクイグアナ
C. subcristatus 学名 Conolophus subcristatus
(Gray, 1831)[3] シノニム

Amblyrhynchus subcristatus Gray, 1831[3] Trachycephalus subcristatus Gray, 1845[3]

和名 ガラパゴスオカイグアナ[4]

ガラパゴスリクイグアナ[5]

英名 Galapagos land iguana

ガラパゴスリクイグアナConolophus subcristatus) は、有鱗目イグアナ科リクイグアナ属に分類されるトカゲ。リクイグアナ属の模式種[3]。別名ガラパゴスオカイグアナ[4]

分布[編集]

エクアドルガラパゴス諸島サウス・プラザ島サンタ・クルス島セイモア・ノルテ島フェルナンディナ島[3][5]固有種

セイモア・ノルテ島の個体は、バルトラ島において第二次世界大戦時に駐留したアメリカ軍により絶滅に瀕した本種を1930年代に人為的に移入したもので、1950年代に絶滅したバルトラ島には、その後再び戻されている[6]。またエスパニョラ島にも生息が認められるが、移入されたものであるかは不明[6]サンチャゴ島に生息した本種は、人為的に移入されて野生化したブタによって19世紀末に絶滅した[6]

形態[編集]

全長1.1メートル[4]。100-120cm[6]。頭胴長40 - 55センチメートル[5]。体重6-13キログラム[6]。背面の色彩は赤や黄色みを帯びた暗褐色[5]。頸部から喉にかけて白い個体が多い[5]。オスのほうが大きく、淡色であり[6]、メスは小さくて体色は鈍い[7]

分類[編集]

2009年にイサベラ島の個体群とされていたものがリクイグアナ属の独立種C. marthaeとして分割・記載された[8]

生態[編集]

主にウチワサボテン類の花や果実を食べるが、昆虫カニ、鳥類の死骸を食べた例もある[5]ウチワサボテンの茎を棘(とげ)とともに食べ、消化できない棘はそのまま排泄する[6]

繁殖様式は卵生。生息する島により繁殖期は異なり、イサベラ島、サウス・プラザ島では1月より、フェルナンディナ島では6月より、サンタ・クルス島においては9月より繁殖する[6][7]。オスはそれぞれ縄張りをもち[6]。繁殖期になるとオス同士で頭部を押し付け合う争いを行う[4][5]。メスはオスの縄張りに侵入してペアを形成し、交尾を行う[5]。8-15年で性成熟し、寿命は60年以上とされる[6]

人間との関係[編集]

開発による生息地の破壊、食用の乱獲、第二次世界大戦中の兵士による狩猟、人為的に移入されたイヌやネコによる捕食、ヤギによる生息地の破壊などにより生息数は激減している[5]。近年では地球温暖化による藻類の減少によってウミイグアナが生息地に進出して来る例が増えており、それによる交雑も発生している。以前はサンチャゴ島バルトラ島にも分布していたが、前者はヤギによる植生の破壊により後者は第二次大戦中の狩猟により絶滅している[5]

  • A Galapagos Land Iguana on the North Seymour Island in the Galapagos photo by Alvaro Sevilla Design.JPG

出典[編集]

[ヘルプ]
  1. ^ Appendices I, II and III<http://www.cites.org/>(accessed July 2, 2016)
  2. ^ World Conservation Monitoring Centre. 1996. Conolophus subcristatus. The IUCN Red List of Threatened Species 1996: e.T5240A11121212. http://dx.doi.org/10.2305/IUCN.UK.1996.RLTS.T5240A11121212.en. Downloaded on 02 July 2016.
  3. ^ a b c d e Conolophus subcristatus. Uetz, P. & Jiri Hosek (eds.), The Reptile Database, http://www.reptile-database.org, accessed April 17, 2016
  4. ^ a b c d 松本通範 「ガラパゴスオカイグアナ」『爬虫類・両生類800種図鑑 第3版』千石正一監修 長坂拓也編、ピーシーズ、2002年、30頁。
  5. ^ a b c d e f g h i j 太田英利 「ガラパゴスリクイグアナ」『動物世界遺産 レッド・データ・アニマルズ3 中央・南アメリカ』小原秀雄・浦本昌紀・太田英利・松井正文編著、講談社2001年、108、262頁。
  6. ^ a b c d e f g h i j 藤原幸一 『ガラパゴス博物学』 データハウス、ISBN 4-88718-616-9。
  7. ^ a b Swash, Andy; Still, Rob (2005). Birds, Mammals and Reptiles of the Galápagos Islands (2 nd ed.). London: Christopher Helm. p. 118. ISBN 978-0-7136-7551-1.
  8. ^ Gabriele Gentile & Howard Snell, "Conolophus marthae sp.nov. (Squamata, Iguanidae), a new species of land iguana from the Galápagos archipelago," Zootaxa, Volume 2201, Auckland New Zealand, Magnolia press, 2009, pp. 1-10

関連項目[編集]

 src= ウィキメディア・コモンズには、ガラパゴスリクイグアナに関連するメディアがあります。  src= ウィキスピーシーズにガラパゴスリクイグアナに関する情報があります。 執筆の途中です この項目は、動物に関連した書きかけの項目です。この項目を加筆・訂正などしてくださる協力者を求めていますPortal:生き物と自然プロジェクト:生物)。
 title=
lisenssi
cc-by-sa-3.0
tekijänoikeus
ウィキペディアの著者と編集者
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia 日本語

ガラパゴスリクイグアナ: Brief Summary ( Japani )

tarjonnut wikipedia 日本語

ガラパゴスリクイグアナ(Conolophus subcristatus) は、有鱗目イグアナ科リクイグアナ属に分類されるトカゲ。リクイグアナ属の模式種。別名ガラパゴスオカイグアナ。

lisenssi
cc-by-sa-3.0
tekijänoikeus
ウィキペディアの著者と編集者
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia 日本語

갈라파고스이구아나 ( Korea )

tarjonnut wikipedia 한국어 위키백과

갈라파고스이구아나(학명 : Conolophus subcristatus)는 이구아나과 육지이구아나속으로 분류되는 파충류이다.

분포

 src=
먹이를 먹는 갈라파고스육지이구아나

에콰도르 갈라파고스 제도이사벨라섬, 남플라사섬, 산타크루즈섬, 북씨모어섬, 페르난디나섬) 고유종

형태

전체 길이 110 - 120cm로, 몸길이는 40 – 55 cm 정도이다. 뒷면의 색상은 빨간색과 노란색만을 띤 어두운 갈색을 가진다. 목 부분에서 목을 두르는 흰색 개체가 많다.

생태

 src=
일광욕을 하는 갈라파고스육지이구아나

육지에서 살며, 지상에 둥지 구멍을 파고 생활한다. 식성은 초식으로 주로 선인장의 잎, 꽃, 과일을 먹는다. 곤충이나 게, 조류의 시체를 먹는 경우도 있다. 선인장 잎은 발톱으로 찢고 턱으로 깨물어 잘게 부순 후 먹는다.

사육 형태는 난생으로 번식기가 되면 수컷끼리 머리를 누르는 의례적인 싸움을 한다. 암컷은 수컷의 세력권을 침입하고 연결을 형성하고, 교미를 한다. 모래땅이나 퇴적한 낙엽에 구멍을 파고, 한 번에 9-25개의 알을 낳으며, 알은 4개월 이내에 부화한다.

인간과의 관계

대항해 시대에는 식용으로 이용했다. 개발에 의한 서식지 파괴, 식용, 남획 인위적으로 데려온 또는 고양이, 돼지에 잡아먹히거나 염소당나귀에 의한 서식지 파괴 등으로 개체수가 격감하고 있다. 제2차 세계 대전 중에는 주둔하고 있던 병사의 수렵도 개체수 감소의 이유라고 생각된다. 예전에는 산살바도르섬과 바루토라섬에 분포하고 있었지만 이미 멸종해 버렸다. 사육 개체를 다시 들여와 외적을 제거하는 등의 보호 대책이 추진되고 있다.

관련 항목

외부 링크

 title=
lisenssi
cc-by-sa-3.0
tekijänoikeus
Wikipedia 작가 및 편집자
alkuperäinen
käy lähteessä
kumppanisivusto
wikipedia 한국어 위키백과