slugs<\/a> and eventually have to chew their food between smooth jaw bones.<\/p>\n\n\n\nIn tuataras, both eyes can focus independently and are specialized with a ‘duplex retina’ that contains two types of visual cells for vision by both day and night and a tapetum lucidum which reflects on to the retina to enhance vision at night. There is also a third eyelid on each eye, the nictitating membrane.<\/p>\n\n\n\n
The tuatara has a third eye on the top of its head called the ‘parietal eye’. It has its own lens, cornea, retina with rod-like structures and degenerated nerve connection to the brain, suggesting it evolved from a real eye. The parietal eye is only visible in hatchlings, which have a translucent patch at the top centre of the skull. After four to six months it becomes covered with opaque scales and pigment. Its purpose is unknown, but it may be useful in absorbing ultraviolet rays to manufacture vitamin D, as well as to determine light\/dark cycles and help with thermoregulation. Of all extant tetrapods, the parietal eye is most pronounced in the tuatara. In mammals, it has become the pineal gland.<\/p>\n\n\n\n
Together with turtles, the tuatara has the most primitive hearing organs among the amniotes. There is no eardrum and the middle ear cavity is filled with loose tissue, mostly adipose tissue. Tuataras respond only to low frequencies.<\/p>\n\n\n\n
Tuatara Behaviour<\/h3>\n\n\n\n
Adult tuataras are terrestrial and nocturnal reptiles, though they will often bask in the sun to warm their bodies. Hatchlings hide under logs and stones and are diurnal, likely because adults are cannibalistic. Tuataras survive in temperatures much lower than those tolerated by most reptiles and hibernate during winter.<\/p>\n\n\n\n
Tuatara Reproduction<\/h3>\n\n\n\n
Tuataras reproduce very slowly, sometimes taking ten years to reach sexual maturity. Mating occurs in midsummer when females mate and lay eggs once every four years. During courtship, a male makes his skin darker, raises his crests and parades toward the female. He circles himself around the female while slowly walking with stiffened legs. The female will either submit and allow the male to mate with her or retreat to her burrow. Males do not have a penis, instead they reproduce by lifting the tail of the female and placing his vent over hers. The sperm is then transferred into the female.<\/p>\n\n\n\n
Tuatara eggs have a soft, parchment-like shell. It takes the females between one and three years to provide eggs with yolk and up to seven months to form the shell. It then takes between 12 and 15 months from mating to hatching. This means reproduction occurs at 2 to 5 year intervals, the slowest in any reptile. The sex of a hatchling depends on the temperature of the egg, with warmer eggs tending to produce male tuataras and cooler eggs producing females. Eggs incubated at 21\u00b0 C have an equal chance of being male or female. However, at 22\u00b0 C, 80% are likely to be males and at 20\u00b0 C, 80% are likely to be females; at 18\u00b0 C all hatchlings will be females.<\/p>\n\n\n\n
Tuatara Life Span<\/h3>\n\n\n\n
Tuataras probably have the slowest growth rates of any reptile, continuing to grow larger for the first 35 years of their lives. The average life span is about 60 years, however, they can live to be over 100 years old.<\/p>\n\n\n\n
Tuatara Conservation Status<\/h3>\n\n\n\n
The tuatara has been classified as an endangered species since 1895. Tuataras, like many of New Zealand’s native animals, are threatened by habitat loss and introduced species, such as mustelids (weasel family) and rats. Tuataras were extinct on the mainland, with the remaining populations confined to 32 offshore islands, until the first mainland release into the heavily fenced and monitored Karori Wildlife Sanctuary in 2005.<\/p>\n","protected":false},"excerpt":{"rendered":"
The Tuatara is a reptile of the family Sphenodontidae, endemic to New Zealand. The two species of tuatara are the only surviving members of the Sphenodontians who flourished around 200 million years ago. The tuataras resemble lizards, but are equally related to lizards and snakes, which are their closest living relatives. For this reason, tuataras […]<\/p>\n","protected":false},"author":6,"featured_media":4132,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","format":"standard","meta":{"_acf_changed":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[3],"tags":[],"animal-category":[59],"endangered":[],"group":[60],"location":[],"acf":[],"_links":{"self":[{"href":"https:\/\/animalcorner.org\/wp-json\/wp\/v2\/animals\/677"}],"collection":[{"href":"https:\/\/animalcorner.org\/wp-json\/wp\/v2\/animals"}],"about":[{"href":"https:\/\/animalcorner.org\/wp-json\/wp\/v2\/types\/animals"}],"author":[{"embeddable":true,"href":"https:\/\/animalcorner.org\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/animalcorner.org\/wp-json\/wp\/v2\/comments?post=677"}],"version-history":[{"count":0,"href":"https:\/\/animalcorner.org\/wp-json\/wp\/v2\/animals\/677\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/animalcorner.org\/wp-json\/wp\/v2\/media\/4132"}],"wp:attachment":[{"href":"https:\/\/animalcorner.org\/wp-json\/wp\/v2\/media?parent=677"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/animalcorner.org\/wp-json\/wp\/v2\/categories?post=677"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/animalcorner.org\/wp-json\/wp\/v2\/tags?post=677"},{"taxonomy":"animal-category","embeddable":true,"href":"https:\/\/animalcorner.org\/wp-json\/wp\/v2\/animal-category?post=677"},{"taxonomy":"endangered","embeddable":true,"href":"https:\/\/animalcorner.org\/wp-json\/wp\/v2\/endangered?post=677"},{"taxonomy":"group","embeddable":true,"href":"https:\/\/animalcorner.org\/wp-json\/wp\/v2\/group?post=677"},{"taxonomy":"location","embeddable":true,"href":"https:\/\/animalcorner.org\/wp-json\/wp\/v2\/location?post=677"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}