Mokopirirakau

Mokopirirakau
Forest gecko (M. granulatus)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Squamata
Family:	Diplodactylidae
Genus:	Mokopirirakau Nielsen, Bauer, Jackman, Hitchmough & Daugherty, 2011

The Mokopirirakau genus comprises alpine geckos found only in New Zealand. The name is Māori, and comes from “Moko”, referring to lizards, and “pirirakau”, which refers to forests ^[1][2]. This is a newly recognized genus as it was previously included in the Hoplodactylus genus ^[3]. Many of the species within this genus are still at candidatus status (are yet to be formally classified) because of this, but also because of the difficulty that comes with researching these species and this genus in particular ^[4]. Much of the current research about geckos in New Zealand is built off assumptions, indicating that better surveying methods are needed to come to any real conclusions about their behaviour and ecology ^[5].

The species in quotation marks are still at candidatus status which means they have not yet been formally classified.

• Mokopirirakau galaxias ^[6]
• Mokopirirajau granulatus ^[7]
• Mokopirirakau nebulosus ^[8]
• Mokopirirakau kahutarae ^[3]
• Mokopirirakau cryptozoicus ^[8]
• Mokopirirakau “cupola” ^[4]
• Mokopirirakau “Roys Peak” ^[9]
• Mokopirirakau “Ōkārito” ^[10]
• Mokopirirakau “Southern North Island” ^[5]
• Mokopirirakau “Open Bay Islands” ^[11]
• Mokopirirakau “Southern Forest” ^[12]
• Mokopirirakau “Cascades” ^[11]

Mokopirirakau along with two other genera can be distinguished from other geckos by their narrow toes, straight or only slightly curved thin toe pads, and specific mouth colouration which can be yellow or dark blue to black ^[4]. These geckos are cryptically coloured. This means they have complex colourations that generally serves a purpose in signalling or camouflage. Select geckos, like Mokopirirakau galaxias, have unique colourations that could be used for signalling; although there has been little to no research into this hypothesis. Especially unique yellow mouth colouration gives Mokopirirakau galaxias its Māori name; “Hura Te Ao”, or “reveal the world”, because of how it looks like the break of dawn. Different colourations in geckos may also be attributed to thermoregulation, but this has not been explored with Mokopirirakau geckos yet ^[13]. Thermoregulation refers to regulating their body temperatures. These geckos do not have specific specialised snout lengths or bite strengths, as would be seen in herbivorous lizards, because they have an omnivorous diet ^[7]. Mokopirirakau geckos have very different maxillae to Woodworthia or Hoplodactylus geckos, and are more similar to those of Naultinus and Dactylocnemis ^[7]. Maxillae are the bones that make up the top of the jaw.

Mokopirirakau geckos are unique in that they live in alpine environments; a habitat that exists because of New Zealand’s geology and large variety of environments ^[9]. These geckos are found throughout the country, with habitats in Otago, the south of the north island of New Zealand, and various other alpine regions ^[9]. Mountainous environments have caused this genus to be well-adapted to extremely cold temperatures and harsh conditions, including potential reproductive adaptations ^[9][14].

The space Mokopirirakau geckos occupy appears to vary a lot, even within species. Outside factors can have a large effect on home ranges and fidelity to sites and site fidelity varies significantly between gecko genera in New Zealand. Home ranges are essentially the space that animals occupy for living, breeding, and foraging. Site fidelity refers to animals staying in the same locations for extended periods of time. Disruptions by humans have an effect on Mokopirirakau geckos; a study showed that Mokopirirakau “Southern Forest” have survived substantial modifications to their habitat by staying within small fragments of undisturbed forest ^[12]. This does not imply that they have adaptations that enable their survival more, instead it highlights how important they are as a species and that conservation efforts need to be improved ^[12]. Site fidelity is an area that requires more research. Most New Zealand geckos have been observed to have strong site fidelity, which means they stay in the same areas a lot of the time ^[5]. In contrast, Mokopirirakau has been noted to have strong short-term site fidelity, indicating they change their habitats frequently ^[5]. This might be unique to the genus, or there could be outside environmental factors that caused this, as this genus inhabits environments not many other animals occupy.

While not many other animals are suited to living in environments like these, there are still risks that come from living in alpine habitats ^[9]. The geckos that live there experience more difficulties with reproduction and as a result are more at risk of population decline ^[9]. Many of the Mokopirirakau geckos are endangered ^[8]. Part of this is due to the effects of human activity and deforestation, but a huge contributor to this is predation of species in this genus ^[15]. Introduced mammalian predators are the main concern in conservation of Mokopirirakau geckos as they threaten a plethora of other native species ^[15]. However, predation is not only attributed to introduced species; native avian or bird species also prey on these geckos ^[15]. New Zealand is well known for its predator free islands, and a potential for conservation of threatened native species is translocation of these species to the predator-free islands ^[16][17]. Translocation refers to the movement of species from one habitat to another. One thing to consider is how the alpine species will be affected by a switch in environments, especially to temperatures warmer than they are used to ^[18]. However, research has already been conducted to test this methodology and has shown some promising results ^[17]. The only factor that would need to be considered is how best to release the geckos, as they performed differently based off how much support they were given in the new environment ^[17]. Geckos that were “hard released” had larger home ranges than geckos that were supported and kept in pens after release ^[17].

Geckos are generally assumed to be omnivorous as are the other lizards in New Zealand ^[15]. However, more research is needed in this area to definitively conclude what Mokopirirakau geckos eat. One source discusses how they eat fruit, but don’t go for nectar that other geckos usually compete with each other for ^[5]. Mokopirirakau “Southern Forest” has been recorded to eat insects which indicates this genus is in fact omnivorous, just not in the same way as is assumed of most other geckos in New Zealand ^[15].

Geckos in New Zealand are generally assumed to be mostly nocturnal ^[5]. This is not necessarily the case, and many assumptions made about New Zealand geckos have proven to be harmful for research in that field ^[5]. Studies have reported “nocturnal” geckos actively foraging during the day, Mokopirirakau “Southern North Island” in particular ^[5]. More research to supplement current knowledge about gecko activity phases is needed and would benefit not just Mokopirirakau but all of New Zealand’s reptiles. In the meantime, the activity phases of Mokopirirakau geckos remains one of their cryptic behaviours. Surveying methods have been improved through the use of trail cams rather than relying on in-person sampling which shows promise for future research ^[19].

A few of New Zealand’s gecko species are arboreal, often found on the trunks of trees and branches of shrubs ^[5]. Arboreal refers to living in trees. This could be unique to this genus as other gecko genera have been observed more in foliage and on stems ^[5]. Similarly, Mokopirirakau geckos do not use retreats as frequently as other gecko genera ^[5]. The study that discussed this noted that this may be due to predator control operations in the site, but it would also be important to note that, aside from avian predators, the majority of the threats to Mokopirirakau and other small arboreal reptiles is introduced mammalian predators ^[5][15][16]. Other geckos tend to use camouflaging foliage or vegetation to hide from perceived threats ^[5].

Mokopirirakau “Southern North Island displays what may be sexual dimorphism, with the biggest female measuring almost a centimetre longer than the biggest male ^[5]. Sexual dimorphism refers to observable differences between sexes, often but not always reflected in size or colour. Sexual dimorphism like this appears to be typical of other New Zealand geckos ^[5]. In contrast, Mokopirirakau “Southern North Island” has the highest reproductive rate of all geckos in New Zealand, which shows promise for population regeneration ^[5]. Females in the “Roys peak” species appear to have higher body temperatures during the day while reproducing than males or females who were not reproducing ^[14]. This could be an adaptation to the extreme alpine temperatures to support reproduction in harsh conditions while reproduction is already difficult ^[9][14]. The relationship between pregnancy and thermoregulation both in this species and for New Zealand reptiles in general has not yet been fully explored and would benefit from more research.