Tag: reptiles

The Castaway: New monitor lizard fills top-order predator role on remote Pacific island

Separated by several hundred kilometres from its next of kin, a new species of blue-tailed monitor lizard unique to the remote Mussau Island has been described. Unknown to science until recently and formally termed the “isolated”, it is the only large-sized land-living predator and scavenger native to the island.

Dubbed a “biogeographical oddity” by its discoverers, led by Valter Weijola, a graduate student from the University of Turku, Finland, the lizard species is also the first new monitor lizard to be described from the country of Papua New Guinea in over twenty years. The finding was published in the open-access journal ZooKeys.

Monitors play an important ecological role in many island ecosystems in the southwest Pacific. Predatory mammals have never colonized the region due to the isolation of these islands. Instead, these large, active and intelligent lizards fill the role of top-predators and scavengers. The Pacific monitor lineage to which the new species belongs have been so successful at oversea dispersal that a number of different species now occupy almost every island from the Moluccas in Indonesia to the eastern Solomon Islands and even Micronesia.

The new endemic species was observed and studied during fieldwork by Weijola and local assistants in the relatively dry coastal vegetation of Mussau, but it is likely that it also persist in the remnants of intact forest in the interior of the island.

The formally described female lizard, or holotype, measures 1 m with the tail being one and and a half times the length of the dominantly black-coloured body covered with yellow and orange markings. The tail of the adults shows varying degrees of turquoise to bluish pigmentation. Another distinctive feature for the species is the pale yellow tongue, which is a trait shared only by three other species of Pacific monitors. The new species is known to eat crabs, other reptiles and their eggs, and small birds.

“Usually monitors like these will eat just about anything they can catch and kill, as well as carcass and turtle eggs when available,” explains Weijola. “While young, Pacific monitor lizards are highly secretive and subsist mainly on insects and other small animals.”

The new species, which can grow to well over a meter in length, was named Varanus semotus, a Latin reference to the remoteness and isolation of the relatively small and partly volcanic island where the lizard was found. Close examination revealed the reptile to be distinct from its relatives from New Guinea and New Britain. Genetic studies, conducted by co-authors Stephen Donnellan, South-Australian Museum, and Christer Lindqvist, Åbo Akademi University, showed that the species has been isolated for a long time, estimatedly 1-2 million years, or even longer.

“Isolation is the keyword here,” says Weijola. “It is what has driven speciation and made the South-Pacific region one of the World’s biodiversity hotspots.” For anything to arrive on Mussau (from New Guinea or New Britain) it would need to cross 250-350 kilometers of open sea, and this doesn’t happen frequently. So, once the ancestor arrived, perhaps in the form of a gravid female, the population must have been completely isolated.””These islands are full of unique creatures often restricted in distribution to just one island or island group,” explains the researcher. “Yet, we know relatively little about them. Even large species of reptiles and mammals are regularly being discovered, not to mention amphibians and invertebrates. This is what makes it such a biologically valuable and fascinating region.”

###

Original source:

Weijola V, Donnellan SC, Lindqvist C (2016) A new blue-tailed Monitor lizard (Reptilia, Squamata, Varanus) of the Varanus indicus group from Mussau Island, Papua New Guinea.ZooKeys 568: 129-154. doi: 10.3897/zookeys.568.6872

The third sister: Long-suspected third desert tortoise species proven to exist in Mexico

The huge variability among the desert tortoise populations of Mexico has finally been given an explanation after casting doubts for several decades. The puzzle was solved by an international team of researchers, led by Dr. Taylor Edwards, The University of Arizona, who teamed up to find out whether there has been a previously unknown third sister species all along. Moreover, unlike their predecessors, the team have managed to provide enough evidence to prove its existence. Their study is published in the open-access journal ZooKeys.

Distributed over a large area stretching from the Mojave and Colorado deserts in the United States to mainland Mexico, the tortoise populations were noticed to vary distinctly back in 1945, when scientists pointed out that the southern populations were suspiciously different. However, due to lack of enough samples and, therefore research, there was not enough evidence to prove that they were in fact two separate species.

Over the span of six years, the team of Dr. Taylor Edwards measured a multitude of tortoises during their field trips in Sonora and northern Sinaloa. This is how they concluded that the southern populations stand out with their significantly shorter tails and flatter carapaces. Unlike its sister species, whose shells are medium to dark brown with greenish hues, while the bodies are dark gray to brownish-gray, the new tortoise is dark tan to medium-brownish with an orange cast.

The new species inhabits exclusively thornscrub and tropical broadleaf forests, which is the reason why out of the three it is the one occupying the smallest geographic range, extending over approximately 24,000 km2.

Although there is not much information about their behaviour, it is presumed that the tortoises activity is strongly correlated with the monsoonal rains and the vegetation growth. The biologists have observed that the adults begin their seasonal activity in June, shortly before plant growth and the monsoons. Then, in December, they would cover underground in their dens, where they would spend the dry and cool winter season.

The new species, called Gopherus evgoodei, receives its name in honour of Eric V. Goode, a conservationist, naturalist, and founder of the Turtle Conservancy.

“He has contributed generously to the conservation of this species via the preservation of land in Mexico, and he actively pursues the conservation of turtles and tortoises on a global scale,” point out the researchers. “Eric sets an important precedent by complementing this taxonomic description with a tangible action that contributes to the conservation of the new species in its native habitat”.

###

Original source:

Edwards T, Karl AE, Vaughn M, Rosen PC, Torres CM, Murphy RW (2016) The desert tortoise trichotomy: Mexico hosts a third, new sister-species of tortoise in the Gopherus morafkai-G. agassizii group. ZooKeys 562: 131-158. doi: 10.3897/zookeys.562.6124

New snake species with pitch black eyes from the Andes highlights hidden diversity

Extremely rare and hidden in the forests of the Andes, there are still new snake species left to find. This has recently been evidenced by the colubrid serpent, described for the first time in the present article. Moreover, there is the vicious circle enwrapping its relatives: the harder it is to find more specimens, the tougher it is to describe and thus, start to identify them, which does not help in mapping their distribution and habitats. To address this issue, Dr. R. Alexander Pyron, The George Washington University, and his international research team have included a taxonomic review and discussion on the relationships and origin within a non-venomous snake tribe in a paper, published in the open-access journal ZooKeys.

Slender and small, the new species, called Synophis zaheri, measures less than 40 cm in length, or between 351 and 372 mm. Contrasting to its slim body with a distinct neck, separating the head from the body, its eyes are large and bulging, making up for more than a third of its head. Being black in colour, it is hard to tell the pupil and the iris apart. While the upper part of the body is grayish-brown with an iridescent sheen, the abdominal side stands out with its yellowish-white colouration.

Typically for the tribe, where the new species has been placed, it is also characterised with a highly modified spine and an enlarged scale row running over it. This is also where the name of this group of snakes comes from with “Diaphorolepidini” consisting of the Greek words for “differentiated” and “scales”. Not so clear, however, is the name of the genus, which the authors have translated also from Greek as “with snake”, but find themselves unaware of the meaning behind. The species is named after Dr. Hussam El-Dine Zaher, a Brazilian herpetologist whose work has been foundational for South American snakes.

In conclusion, the scientists note that the rarity of the observed snake species, especially the genus, where the new serpent belongs, accounts for the unclear species-boundaries as well as for the myriad of undescribed species. “Dipsadine diversity in the Andes is clearly underestimated, and new species are still being discovered in the 21st century,” they point out.

###

Original source:

Pyron RA, Guayasamin JM, Peñafiel N, Bustamante L, Arteaga A (2015) Systematics of Nothopsini (Serpentes, Dipsadidae), with a new species of Synophis from the Pacific Andean slopes of southwestern Ecuador. ZooKeys 541: 109-147. doi: 10.3897/zookeys.541.6058

Counting stars: Illegal trade of Indian star tortoises is a far graver issue

Patterned with star-like figures on their shells, Indian star tortoises can be found in private homes across Asia, where they are commonly kept as pets. One can also see them in religious temples, praised as the living incarnation of the Hindu god Vishnu. How did they get there? Suspicious of a large-scale illegal international trade of these tortoises that could in fact pose a grave threat to the survival of the Indian Star tortoise, a team of researchers, led by Dr. Neil D’Cruze from Wildlife Conservation Research Unit, University of Oxford, and World Animal Protection, London, spent 17 months investigating the case focusing on India and Thailand. They have their study published in the open-access journal Nature Conservation.

The present study established that at least 55,000 Indian star tortoise individuals are being poached over the span of a year from a single trade hub in India. Helped by a number of herpetologists and wildlife enforcement officials, the researchers have tracked signals about how sophisticated criminal gangs are exploiting “legal loopholes” and people alike, taking advantage of rural communities and urban consumers in India and other Asian countries.

“We were shocked at the sheer scale of the illegal trade in tortoises and the cruelty inflicted upon them,” comments Dr. Neil D’Cruze. “Over 15 years ago wildlife experts warned that the domestic trade in Indian star tortoises needed to be contained before it could become established as an organised international criminal operation.”

“Unfortunately, it seems that our worst nightmare has come true – sophisticated criminal gangs are exploiting both impoverished rural communities and urban consumers alike,” he also added. “Neither group is fully aware how their actions are threatening the welfare and conservation of these tortoises.”

Although deemed of “Least Concern” on the IUCN Red List when last formally assessed back in 2000, the Indian star tortoise and its increasing illegal poaching and trading can easily lead to a serious risk of the species’ extinction. Other dangers of such unregulated activities include the introduction of invasive species and diseases.

Having spent a year among a rural hunter-gatherer community, researchers established the collection of at least 55,000 juvenile wild Indian star tortoises between January and December 2014. This is already between three and six times more than the last such record dating from about ten years ago.

Collectors tend to poach juvenile tortoises, but it is not rare for them to also catch adults. Based on the individual’s age and health, the tortoises are later sold to vendors at a price of between 50 and 300 Indian Rupees (INR), or between 1 and 5 USD, per animal. “Therefore, we conservatively estimate (assuming no mortalities) that the collector engagement in this illegal operation has a collective annual value of up to 16,500,000 INR (263,000 USD) for their impoverished communities,” comment the researchers.

Consumers seek the Indian star tortoise for either exotic pets or spiritual purposes. With their star-like radiating yellow patterns splashed with black on their shells, not only is this tortoise species an attractive animal, but it was also found to be considered as a good omen among the locals in the Indian state of Gujarat. During their survey, the researchers found over a hundred hatchlings in a single urban household. However, their owner claimed that none of them was kept with commercial intent, although some of the tortoises were meant for close friends and relatives.

On the other hand, there was a case where the researchers came across a Shiva temple hosting a total of eleven Indian star tortoises. Temple representatives there confirmed that the tortoise is believed to represent an incarnation of the Hindu god Vishnu, one of the three central gods in the religion, recognised as the preserver and protector of the universe.

In India vendors do not show the reptiles in public, but they are made available upon a special request. If paid for in advance, a vendor can also supply a larger quantity of the animals at a price ranging from 1,000 to 3,000 INR (15 to 50 USD) per animal. The researchers managed to see seven captive tortoises in private, including six juveniles and one adult, all in visibly poor health. Disturbingly, in order to reach these vendors, the collected tortoise are usually wrapped in cloths and packed into suitcases. Covered by a ‘mask’ of legal produce such as fruit and vegetables, they are transported to the ‘trade hubs’. They are also smuggled abroad to satisfy consumer demand among the growing middle classes in countries such as Thailand and China.

“Despite being protected in India since the 1970’s, legal ‘loopholes’ in other Asian countries such as Thailand and China appear to undermine India’s enforcement efforts,” explains Mr. Gajender Sharma, India’s Director at World Animal Protection, “They are smuggled out of the country in confined spaces, it’s clear there is little or no concern about the welfare of these reptiles.”

“World Animal Protection is concerned about the suffering that these tortoises endure,” he further notes. “We are dealing with an organised international criminal operation which requires an equally organised international approach to combat it.”

As a result of their study, the authors conclude that more research into both the illegal trafficking of Indian star tortoise and its effects as well as the consumer demand is urgently needed in order to assess, address and subsequently tackle the issue.

###

Original source:

D’Cruze N, Singh B, Morrison T, Schmidt-Burbach J, Macdonald DW, Mookerjee A (2015) A star attraction: The illegal trade in Indian Star Tortoises. Nature Conservation 13: 1-19. doi:10.3897/natureconservation.13.5625