Introduction
Unsustainable harvesting for the wildlife trade has caused the decline of a number of lesser known species of herpetofauna (Schlaepfer et al., Reference Schlaepfer, Hoover and Dodd2005). Moreover, when species are removed from the environment, the ecological contributions they make to ecosystems are reduced or eliminated (Miranda, Reference Miranda2017). The trade in wildlife, both legal and illegal, is a multibillion-dollar industry and is one of the foremost causes of population declines, extirpations and increased extinction risks (Symes et al., Reference Symes, McGrath, Rao and Carrasco2018).
To regulate global wildlife trade, CITES was established to protect species already threatened by trade from further losses and extinction (Janssen & Shepherd, Reference Janssen and Shepherd2018). The organization controls the wildlife trade with a focus on species of conservation concern amongst its 183 signatory countries (CITES, 2016). This regulation is managed by a system of appendices and permits/licenses (CITES, 2015, 2016). However, many species subject to international trade and in need of tighter regulation are yet to be placed under CITES restrictions (Janssen & Shepherd, Reference Janssen and Shepherd2018).
Many subsistence societies depend on wildlife as a source of protein (Boesch et al., Reference Boesch, Mundry, Kuhl and Berger2017; Cornelio, Reference Cornelio2020). Among Indigenous societies of Melanesia, the natural environment and its wildlife contribute significantly to livelihoods (Pollard et al., Reference Pollard, Thaman, Brodie and Morrison2015; Brodie & Pangau-Adam, Reference Brodie and Pangau-Adam2017), and to human physical and spiritual well-being (Naeem et al., Reference Naeem, Chazdon, Duffy, Prager and Worm2016; Pikacha, Reference Pikacha2020). Birds (Cornelio, Reference Cornelio2020), mammals and reptiles are regularly hunted (Pikacha, Reference Pikacha2008) or opportunistically killed as a source of protein. Over the past 3 decades, hunting practices in Melanesia have shifted from a mainly subsistence pursuit to a commercial enterprise, propelled by the advent of wildlife and pet markets, both within the region (Pangau-Adam et al., Reference Pangau-Adam, Noske and Muehlenberg2012) and internationally (Leary, Reference Leary1990, Reference Leary1991).
In the first review of the trade in terrestrial wildlife in the Solomon Islands, Leary (Reference Leary1991) reported the prehensile-tailed skink Corucia zebrata to be the most commonly exported species. Between 1987 and 1989, CITES permits showed a total of 5,886 individuals were exported from the country (Leary, Reference Leary1990). In 1991, a further 3,365 individuals were exported (Leary, Reference Leary1991), and during 1998–2002, 5,924 skinks were exported to the USA (Schlaepfer et al., Reference Schlaepfer, Hoover and Dodd2005). Based on its life history traits, geographical distribution and levels of trade, the prehensile-tailed skink has been identified as one of the reptile species in the Solomon Islands most likely to be threatened by commercial take (Hagen et al., Reference Hagen, Harlow, Allison, Hamilton and Tallowin2021). During 2000–2020, about half (5,728 out of 11,187) of the exports of the prehensile-tailed skink allocated for trade from the Solomon Islands were imported into the USA (CITES, undated).
The Solomon Islands Wildlife Protection and Management Act 1998 provides the legal protection for the conservation and management of wildlife, regulating the trade of animals and plants from the country (South Pacific Regional Environment Program, 2018). However, it is not uncommon in the Solomon Islands for the decisions made for the management, handling and export of wildlife to be swayed by political and economic gains rather than scientific data (Parsons et al., Reference Parsons, Rose and Telecky2010). All prehensile-tailed skinks imported into the USA during 2000–2020 were either wild-caught (4,629 individuals), captive bred (783 individuals), of unknown source (310 individuals), or confiscated (6 individuals; CITES, undated). However, there are no captive breeding facilities in the Solomon Islands, and the size of wild populations is unknown (Hagen et al., Reference Hagen, Harlow, Allison, Hamilton and Tallowin2021). Additionally, despite the absence of captive breeding facilities in the Solomon Islands for birds, high quantities of both native and non-native birds are exported from the country (Shepherd et al., Reference Shepherd, Stengel and Nijman2012). This means that reports in the CITES database of the source of reptiles and birds exported from the Solomon Islands as captive bred are probably incorrect and fraudulent.
The prehensile-tailed skink is endemic to the Solomon Islands archipelago (McCoy, Reference McCoy2006; Hagen et al., Reference Hagen, Donnellan and Bull2012). It occurs on most of the large islands, with the western-most population on Buka in the Autonomous Region of Bougainville (Papua New Guinea), and the eastern-most population on Makira island (McCoy, Reference McCoy2006; Hagen et al., Reference Hagen, Donnellan and Bull2012). It is the largest arboreal skink (McCoy, Reference McCoy2006), a forest specialist (Richmond et al., Reference Richmond, Travers and Backlin2018), herbivorous (Cooper, Reference Cooper2000), and the only known species of skink with a prehensile tail (McCoy, Reference McCoy2006). Its home range is usually limited to the canopy of a single tree (Hagen & Bull, Reference Hagen and Bull2011), and the reproductive rate of this live-bearing species is relatively low, as females bear only one or two young following a 6–7 month gestation (McCoy, Reference McCoy2006).
The prehensile-tailed skink is categorized as Near Threatened on the IUCN Red List because of significant decline, possibly at a rate of 30% over 10 years (Hagen et al., Reference Hagen, Harlow, Allison, Hamilton and Tallowin2021). Several threats are evident: the species is prized bushmeat (Moyle et al., Reference Moyle, Travers, Boseto, Campillo, Klicka and Brown2015; Pollard et al., Reference Pollard, Thaman, Brodie and Morrison2015), its habitat is being exterminated at an unprecedented rate (Global Witness Report, Reference Global Witness Report2018), it is preyed upon by raptors (Pikacha et al., Reference Pikacha, Sirikolo, Boseto and Filardi2012) and threatened by illegal collection for the pet trade (Hagen et al., Reference Hagen, Harlow, Allison, Hamilton and Tallowin2021). The combination of high volumes of trade in wild-caught individuals, traditional hunting pressure, loss of forests and a low reproductive rate could potentially cause the extirpation of the prehensile-tailed skink on some islands. There has been no study on the traditional collection of the prehensile-tailed skink, on perceptions of its conservation status, or an analysis of the pressures of commercial trade.
Here we present the first study of the prehensile-tailed skink based on traditional ecological knowledge. Using questionnaire surveys and informal interviews, we examine the interaction of people with the prehensile-tailed skink, examine perceptions of abundance and population trends, and record the perceived threats to the species. Based on our findings, we present recommendations for conservation and management of the prehensile-tailed skink in the Solomon Islands.
Study area
The Solomon Islands form one of the largest archipelagos in the South Pacific, with 992 islands (Fig. 1; Pikacha, Reference Pikacha2008) and a human population of 721,455 (Solomon Islands National Statistics Office, 2020). The main islands in the north include Bougainville (Autonomous Region of Bougainville, Papua New Guinea), Choiseul and Isabel, and to the south the New Georgian islands, Guadalcanal, Malaita and Makira. The main islands comprise tropical rainforest (Pikacha, Reference Pikacha2017), with 79.1% forest cover, and 49.9% categorized as primary forest (Mongabay, undated). During 1990–2010, 4.8% (111,000 ha) of forest cover was lost (Mongabay, undated). The country has reported high, unsustainable harvesting of timber (Katovai et al., Reference Katovai, Edwards and Laurance2015; Global Witness Report, Reference Global Witness Report2018). The climate is relatively constant throughout the year but with seasonal changes in rainfall (Pacific Climate Change Science Portal, 2011).
Methods
During January–May 2020, we conducted a questionnaire survey with community members from 75 coastal, 36 lowland (2–5 km from the coastline) and 35 inland villages (> 5 km from the coastline; Supplementary Table 1; Fig. 1). Prehensile-tailed skinks (Plate 1) are opportunistically hunted as a food source on all of the islands on which we conducted a survey (McCoy, Reference McCoy2006; Pikacha, Reference Pikacha2008; Hagen et al., Reference Hagen, Harlow, Allison, Hamilton and Tallowin2021).
Fig. 1 The number of survey respondents across the range of the prehensile-tailed skink Corucia zebrata in the Solomon Islands.
Plate 1 A wild prehensile-tailed skink Corucia zebrata in a hill forest on Kolombangara Island, Solomon Islands. Photos: Dylan Bush.
Sampling approach and data collection
We designed a questionnaire following examples used by similar ethnozoological studies (Jaroli et al., Reference Jaroli, Mahawar and Vyas2010) of threatened and cryptic (Soewu, Reference Soewu2008; Pedregosa-Hospdarsky et al., Reference Pedregosa-Hospdarsky, Hospodarsky, Castro, San Jose, Abalajon and Alpas2009) and traded wildlife (TRAFFIC, 2008). The questionnaire interviews were conducted by DB, HB and PGP with the help of research assistants, in the Unu (Makira island) and Marovo (New Georgia, Nggatokae and Vangunu islands) languages, and for other islands in pidgin, the lingua franca (Jourdan, Reference Jourdan, Selbach, Cardoso and van den Berg2009). We aimed to interview equal numbers of respondents from each age group. However, the demographic bias of the Solomon Islands population (with a high proportion of the population < 30 years of age; South Pacific Regional Environment Program, 2019; Solomon Islands National Statistics Office, 2020) was reflected in the age composition of the respondents. We selected informants from a variety of locations, with varying levels of experience, and who had regular interaction with the forest, such as hunters or forest dwellers.
We used a mixed-method approach (Creswell & Creswell, Reference Creswell and Creswell2018) to generate information about threats to the prehensile-tailed skink, with 146 questionnaires and 12 qualitative semi-structured interviews. The semi-structured interviews were on Ulawa island by HB, and on Vangunu island by PGP. The questionnaire (Supplementary Material 1) had five sections, to identify: (1) informant data, (2) knowledge of the forest, (3) perception of population trends of the prehensile-tailed skink (abundant, rare, unsure), (4) observations of habitat and feeding resources of the skink, and (5) perceptions of the best conservation approaches that could be used. We classified habitats using the established Solomon Islands forest types: montane, hill or ridge, lowland and coastal (Shenk, Reference Shenk1994). We also questioned whether the species was tabu (Solomon pidgin: to ban, or ‘no take’), an Indigenous resource management method practised throughout Melanesia (Whitmore et al., Reference Whitmore, Lamaris, Takendu, Charles, Chuwek and Mohe2016; Basel et al., Reference Basel, Goby and Johnson2020) that involves setting up a no harvest zone in a patch of forest or on a reef. This ban on resource harvesting may be occasioned by the death of a chief or village elder, or in preparation for a forthcoming community feast. The length of the ban is determined by the chief, village elders and resource dependent communities, and is of variable length (from a few months to several years; Whitmore et al., Reference Whitmore, Lamaris, Takendu, Charles, Chuwek and Mohe2016).
Data on the export of wildlife from the Solomon Islands was acquired from CITES (undated; UNEP-WCMC, 2013) for 2000–2020. We extracted data for the prehensile-tailed skink on numbers exported and the countries of import.
Data analysis
We analysed questionnaire responses quantitatively using the MASS library (Venables & Ripley, Reference Venables and Ripley2002) in R 4.0.2 (R Development Core Team, 2016). We used log-linear models to test whether perceptions about the abundance of the prehensile-tailed skink, knowledge of tabu protection relevant to the species, amount of time spent in the forest, and responses to finding prehensile-tailed skinks in the forest varied with age or island of residence. We also compiled statistics on the perceptions of preferred habitat type and the most important food resources for the species.
Results
Trade of prehensile-tailed skinks
During 2000–2003, high numbers of prehensile-tailed skinks were exported from the Solomon Islands. The trade declined to almost zero in 2009, with no exports until 2015 when the trade resumed and increased (Fig. 2). Most of the skinks exported were declared to have been sourced from the wild (Fig. 2). The majority of exports were to the USA, followed by Japan, France, Slovenia, Malaysia and Thailand, and with a few exports to six other countries (Fig. 3).
Fig. 2 The number of prehensile-tailed skinks, including their parts and derivatives, exported from the Solomon Islands during 2000–2020 recorded as captive-bred, confiscated or seized, farmed or born in captivity (but note this may not comply with the definition of ‘bred in captivity’ in CITES Resolution Conf. 10.16 (Rev.)), of unknown source, and sourced from the wild (UNEP-WCMC, 2013).
Fig. 3 Summary of the countries importing prehensile-tailed skinks, including their parts or derivatives, from the Solomon Islands during 2000–2020, recorded as captive-bred, confiscated or seized, farmed or born in captivity (but note this may not comply with the definition of ‘bred in captivity’ in CITES Resolution Conf. 10.16 (Rev.)), of unknown source, and sourced from the wild (UNEP-WCMC, 2013).
Frequency of visits to the forest by respondents
There was no relationship between how many days per year respondents visited the forest and their age (F = 0.34, df = 4, P = 0.89) or the location (or distance from the coastline) of their village (F = 0.34, df = 2, P = 0.72). However, there was between-island variation in how many days per year respondents visited the forest (F = 5.27, df = 10, P < 0.01). On average, respondents from Guadalcanal, Isabel, New Georgia, Nggatokae, Rendova, Ulawa and Vangunu islands visited the forest more often than respondents on other islands (Fig. 4, Supplementary Table 2).
Fig. 4 Responses of a total of 146 interviewees from 12 islands to the question ‘How much time do you spend in the forest per year?’. The centre line indicates the median, the box the interquartile range, the whiskers 1.5 × the interquartile range, and the dots indicate outliers.
In response to the question about whether there has been alteration to primary forests or not, most reported observing some change, and a low per cent reported there had been no change, little change or a big change (Table 1). The 90% of respondents that reported seeing changes described these alterations as having been the result of deforestation (from gardening, logging and establishment of coconut plantations), increased landslides, flooding, reduced river flow and rivers drying, and overharvesting of forest foods. The 4% of respondents that reported having seen no change to the forest were from Zaira village, located within an intact forest corridor extending from lowland to montane forests on Vangunu Island. The residents of Zaira reported only the use of traditional subsistence gardening.
Table 1 Per cent of responses of 146 respondents to the question ‘Have you seen change to the forest in your specific area over your lifetime?’, with the types of changes perceived.
Habitat and diet
To the question ‘In what forest type or habitat have you encountered prehensile-tailed skinks?’ most respondents stated lowland forests, followed by other forest types, or the intersection between forest types (Supplementary Table 3, Fig. 5). When respondents were asked ‘What is the state of the forest where the prehensile-tailed skinks were seen?’ most respondents in all age groups stated that the forest was undisturbed. Other respondents reported encounters with the skink in both disturbed and undisturbed forest, some observed the species in disturbed forest, and a few were unsure (Supplementary Table 3).
Fig. 5 Venn diagram showing per cent of responses of 146 respondents to the question, ‘In what forest type or habitat have you encountered prehensile-tailed skinks?’. Overlaps between circles indicate where respondents listed multiple forest types. MO, montane; HR, hill or ridge; LL, lowland; CO, coastal.
Regarding the skink's diet, the majority of respondents (52%) stated that leaves, such as those of Ficus benjamina, Ficus tinctoria, Ficus virgata, Ficus glandulifera, Ficus wassa, Ficus copiosa, Gnetum gnemon and Epipremnum sp. (Ahuto or mama'a in Unu, Makira Island), were the main diet. Other foods mentioned by respondents were fruits (5%), ferns (3%) and vines (3%); 37% of respondents were unsure about the species’ diet.
Hunting and conservation
There was age-dependent variation in the responses to the question ‘What do you do to the prehensile-tailed skinks when you see them in the forest?’. Younger people (aged ≤ 30 years) reported killing prehensile-tailed skinks more frequently than older people (aged > 30 years) (F = 2.80, df = 5, P = 0.02; Fig. 6a). The highest rates of hunting were reported from Makira (80% of respondents), followed by Isabel (38%), Guadalcanal (15%), Choiseul (11%), Savo (11%), Malaita (10%), Vangunu (9%) and New Georgia (4%). There was no hunting reported on Nggatokae, Rendova, and Ulawa islands. On Nggatokae, the majority of people follow the Seventh-Day Adventist Church, whose tenets forbid the consumption of the species. On Rendova and Ulawa, the majority of respondents visited the forest to attend to gardens, subsequent to harvesting bush material, and cutting and milling timber (Supplementary Table 2). All respondents on Guadalcanal and Makira (100%), and nearly all on Isabel, reported that prehensile-tailed skinks were killed for food (Fig. 6b).
Fig. 6 Responses of a total of 146 interviewees to the question ‘What do you do when you see the prehensile-tailed skink?’ by (a) age group, and (b) island.
In response to the question ‘What are the major threats to the prehensile-tailed skinks?’ respondents identified habitat loss (73% of respondents), hunting (17%) and predation (6%); 3% were unsure and one respondent stated the impacts of climate change. A large per cent of respondents on Vangunu (89%), Choiseul (72%), Makira (70%) and Malaita (70%) reported that skink populations were in decline (Supplementary Table 2), whereas a large per cent of respondents on other islands thought skink populations were abundant or stable: Guadalcanal (95%), New Georgia (92%), Savo (78%), Nggatokae (70%), Ulawa (66%), Rendova (56%) and Isabel (50%) (Supplementary Table 2).
There was no relationship between respondents' age and when they last saw the prehensile-tailed skink (F = 1.057, df = 5, P = 0.39). The perceptions of whether the skink was rare or abundant depended on how much time they spent in the forest (F = 5.15, df = 1, P = 0.03) and on the island on which they lived (F = 6.05, df = 10, P < 0.01). The majority of respondents believed prehensile-tailed skinks were still abundant (59%), with fewer reporting them to be rare (36%), and 5% being unsure (Fig. 7).
Fig. 7 Responses of 146 interviewees to the question ‘Do you think the prehensile-tailed skink is rare or abundant, or are you unsure?’ by island.
Traditional conservation
In response to the question ‘Is the prehensile-tailed skink traditionally a tabu or a managed species?’, the majority of respondents indicated it is not (Fig. 8). The majority of respondents on Choiseul, Guadalcanal and Ngella and Savo were unsure, whereas respondents on most other islands indicated the skink is not tabu (Fig. 8). A few respondents from Guadalcanal, New Georgia, Nggatokae, Rendova and Ulawa islands said the skinks were protected by the setting aside of traditional no-take zones. A respondent on Ulawa stated the skink is historically important, as the animal is depicted on traditional wooden bowls. To conserve this species, respondents recommended direct species conservation, preservation of habitat and improving awareness, and a few were unsure what to recommend (Table 2).
Fig. 8 Responses to the question ‘Is the prehensile-tailed skink traditionally a tabu or protected, or a managed species?’, by island.
Table 2 Per cent of responses of 146 respondents to the question ‘How would you protect the prehensile-tailed skink?’, including conservation approaches recommended by the respondents, and descriptions and notes from interviews.
Discussion
Despite the popularity of the prehensile-tailed skink in the live pet trade, limited information is available on the biology of this species in the wild. This reflects the absence of scientific study, but not necessarily that knowledge of the species is lacking. The Indigenous people of the Solomon Islands have traditional knowledge of the prehensile-tailed skink, and we have presented some of this here for the first time, along with people's perceptions of the conservation status of this species and the demographics of hunters.
Our study highlights the cultural and economic dependence of rural Solomon Islands communities on forests. Some respondents spent more than half of the year engaged in some way with the forest. Forests provide food (Lavery et al., Reference Lavery, Pikacha and Fisher2016), building materials (Pikacha, Reference Pikacha2008), logs (Katovai et al., Reference Katovai, Katovai, Laurance, Roberts, Nath, Paul and Madhoo2021) and wildlife that is sold to generate income (Shepherd et al., Reference Shepherd, Stengel and Nijman2012). As expected, the majority of respondents reported seeing changes to the forest in their lifetime. The Solomon Islands have experienced extensive unsustainable logging and loss of critical habitats for many species (Morrison et al., Reference Morrison, Pikacha, Pitakia and Boseto2007; Lavery et al., Reference Lavery, Pikacha and Fisher2016; Global Witness Report, Reference Global Witness Report2018).
Research suggests that the principal habitat of the prehensile-tailed skink is lowland primary forest (McCoy, Reference McCoy2006; Hagen & Bull, Reference Hagen and Bull2011) but our respondents believed the species inhabits a range of forest types, including disturbed or secondary forests. It is not unusual to find the prehensile-tailed skink at disturbed forest sites near villages, occupying a single strangler fig tree Ficus sp. (Hagen & Bull, Reference Hagen and Bull2011; Boseto & Pikacha, Reference Boseto and Pikacha2016; Hagen et al., Reference Hagen, Harlow, Allison, Hamilton and Tallowin2021). Secondary forests comprise a substantial proportion of forest cover (Chokkalingam & Jong, Reference Chokkalingam and De Jong2001), and are also habitat for other endemic and native reptiles such as the western crocodile skink Tribolonotus pseudoponceleti, Solomon Islands blue-tailed skink Emoia pseudocyanura, Solomons tree dragon Hypsilurus macrolepsis and white-striped cape skink Eugongylus albofasciolatus (Lavery et al., Reference Lavery, Pikacha and Fisher2016). Our respondents reported that the prehensile-tailed skink is abundant. Quantifying this abundance is problematic, as most animals are recorded after trees are felled (Read & Moseby, Reference Read and Moseby2006) and the species is difficult to see in the forest canopy (Richmond et al., Reference Richmond, Travers and Backlin2018; Hagen et al., Reference Hagen, Harlow, Allison, Hamilton and Tallowin2021).
The impacts of commercial logging vary depending on species biology, and negative impacts on some vertebrates may be less than generally assumed (Meijaard et al., Reference Meijaard, Sheil, Nasi, Augeri, Rosenbaum and Iskandar2005). The impacts of commercial logging on forest bats in the Solomon Islands was greatest for endemic species (Lavery et al., Reference Lavery, Posala, Tasker and Fisher2020). In addition to being endemic to the Solomon Islands, life history traits (e.g. large-bodied, slow moving, low reproductive output, small home range) may predispose the prehensile-tailed skink to a high risk of extinction (McCoy, Reference McCoy2006; Meijaard & Sheil, Reference Meijaard and Sheil2008; Hagen & Bull, Reference Hagen and Bull2011). However, a limited home range (Hagen & Bull, Reference Hagen and Bull2011) and a preference for large strangler figs (Boseto & Pikacha, Reference Boseto and Pikacha2016) may reduce the impacts of logging on the species (McCoy, Reference McCoy2006). Strangler figs are not a commercially valuable species, and loggers often leave them standing. It is possible that prehensile-tailed skinks can persist in human-altered forests provided their host trees remain intact. The prehensile-tailed skink was caught in the interior forests of Malaita at Gofou, an area that was logged just prior to biodiversity surveys conducted by Kansas University (Moyle et al., Reference Moyle, Travers, Boseto, Campillo, Klicka and Brown2015).
It may be that people's knowledge of the distinct habitat of the species makes it vulnerable to hunting pressures. On Makira the majority of respondents reported hunting as the reason for visiting the forest, and said the species was declining. In contrast, on Guadalcanal the majority of people interviewed said the species was still abundant. Our results showed that most people visited the forest for gardening rather than hunting. Regardless of the reasons for visiting the forest, there is opportunistic hunting and killing of the skinks for food (McCoy, Reference McCoy2006; Pikacha, Reference Pikacha2008), and the species is frequently observed in disturbed habitats (Boseto & Pikacha, Reference Boseto and Pikacha2016). Moreover, cultural differences exist with respect to the ability or willingness of local people to catch lizards. Some people showed a willingness to hunt them, whereas others were less enthusiastic (Hagen & Bull, Reference Hagen and Bull2011).
There was a halt in the export of prehensile-tailed skinks during 2009–2014. The cause of this is unclear, but the CITES database reported an increase in live coral exports during the same period (CITES, undated). Harvesting of wild coral provides one of the highest cash returns for resource-dependent communities in the Solomon Islands (Albert et al., Reference Albert, Trinidad, Boso and Schwarz2012). In rural areas where many rely on natural resources, harvesting a variety of species is part of a livelihood strategy (Robinson et al., Reference Robinson, Griffiths, Fraser, Raharimalala, Roberts and St. John2018).
A greater proportion of people under 30 years of age reported killing skinks than did older respondents. This might represent a loss of awareness of the traditional cultural protection of tabu, which is often put in place for certain species in the Solomon Islands. Most respondents, regardless of age, indicated the skink is not a protected species, but more young people were unsure about whether the species was tabu or not. This could mean that this information is being lost, or that younger people have not had time to learn it. Pollard et al. (Reference Pollard, Thaman, Brodie and Morrison2015) reported that prehensile-tailed skinks are used as a ceremonial food and as a sacrificial offering for magic, and figure in folklore stories.
In resource-dependent communities, crocodiles, snakes, and lizards are vital food sources, yet with the exception of some lizards these are preyed on to a lesser degree and often in a subsistence manner (Klemens & Thorbjarnarson, Reference Klemens and Thorbjarnarson1995). There are few exemplars of well-managed, sustainable harvest programmes for reptiles that are economically viable and culturally acceptable.
Only 0.28% of terrestrial ecosystems of the Solomon Islands are formally protected, and logging and agriculture continue to cause habitat loss, fragmentation and degradation (Katovai et al., Reference Katovai, Edwards and Laurance2015; Global Witness Report, Reference Global Witness Report2018). Prolonged unrestrained exploitation of the Solomon Islands' forests by logging (Global Witness Report, Reference Global Witness Report2018) and hunting (Moyle et al., Reference Moyle, Travers, Boseto, Campillo, Klicka and Brown2015) may lead to extirpation of the prehensile-tailed skink in areas where it is heavily collected (Leary, Reference Leary1990). To address the intractable challenges of managing the exploitation of prehensile-tailed skinks in the wild, we make five recommendations.
Firstly, a distinctive attribute of the prehensile-tailed skink is its herbivorous diet (Wright & Skeba., Reference Wright and Skeba1992), which comprises mostly leaves, and our findings show a link between intact forests and the species’ presence. We recommend that forests that provide the diversity of plants necessary for the species’ dietary requirements be protected through the Solomon Islands Protected Areas Act (2010) (Myren, Reference Myren2018).
Secondly, we recommend a total ban on the export of wild-caught prehensile-tailed skinks.
Thirdly, given present high rates of deforestation in the Solomon Islands and high numbers of the skink collected for the pet trade, captive breeding may be imperative for the trade to be sustainable (Mann & Meek, Reference Mann and Meek2004). We recommend the establishment of ethical and well managed captive breeding facilities that afford qualified animal husbandry and veterinary care (Wadding et al., Reference Wadding, Mann, Davies and Meek2004). To outcompete the harvesting of wild skinks, captive breeding needs to be more cost-effective and less labour intensive than obtaining skinks from the wild. With the long history of captive breeding of prehensile-tailed skinks in the pet trade (Wright, Reference Wright1993), captive populations have the potential to accomplish a higher output than wild populations. Commercial breeding can curb pressure on wildlife populations and support species conservation (Tensen, Reference Tensen2016).
Fourthly, a sweeping change in research priorities, monitoring efforts, and legislation is critical to guarantee that commercial harvesting of wild-caught prehensile-tailed skinks is reconcilable with their long-term existence. CITES wildlife export data (CITES, undated) show that the Solomon Islands have the greatest export of wild-captured reptiles in the South-west Pacific. We recommend a comprehensive review of the export industry, especially with regard to its impact on wild stocks, and improved regulation of the export of prehensile-tailed skinks by CITES. Stringent controls on importing and exporting as per CITES policies are known to have positive conservation effects on species (Doukakis et al., Reference Doukakis, Pikitch, Rothschild, DeSalle, Amato and Kolokotronis2012).
Fifthly, we recommend that ecological and conservation information on the prehensile-tailed skink, an iconic Solomon Islands species, be inserted into primary and high school curricula, to highlight the importance of protecting this endemic species. Educating children has the potential to contribute significantly to the present and future conservation of this unique reptile species.
Acknowledgements
We thank all the respondents and communities who participated in the questionnaire survey; our research assistants Cornelius Qaqara, Doris Raumae, Felix Naitoro, Isaac Qoloni, John Pita, Lina Dorovolomo, Michael Vaghi, Obrent Oti, Watson Qalopui, and the many other research assistants who assisted with field work; Myknee Sirikolo for plant identifications; and David Blair for editing help. This work was facilitated by the Ministry of Environment, Climate Change, Disaster Management and Meteorology, Solomon Islands National Government, to support the Environment and Conservation Division work plan.
Author contributions
Project design: DB, IT, PGP; survey design: PGP; surveys: DB, HB, PGP; securing funding and permits: JH; data analysis, writing: PGP, THL; revision: all authors.
Conflicts of interest
The Ministry of Environment, Climate Change, Disaster Management and Meteorology, Solomon Islands Government, provided financial support for this research to the organization Ecological Solutions–Solomon Islands.
Ethical standards
This research abided by the Oryx guidelines on ethical standards and was approved by a research committee within the Environment Department, Solomon Islands Government (ethics permit MECDM020311), and conforms with ethical standards for community engagement in the Solomon Islands.
Open access
