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Subject: search.filters.subject.Hoplodactylus duvaucelii

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    An assessment of the suitability of captive-bred founders for lizard restoration projects using Duvaucel's geckos (Hoplodactylus duvaucelii) : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Science in Conservation Biology, Massey University, Albany, New Zealand
    (Massey University, 2016) Glenday, Vivienne
    Sourcing founders for species restoration projects can be problematic, especially when using rare or endangered animals. Harvesting from small natural populations could be detrimental to those populations. A possible solution is to use captive-bred founders as this would reduce harvesting pressure on natural source populations. In the summer of 2013, a combination of captive-bred and wild-sourced Duvaucel’s geckos (Hoplodactylus duvaucelii) were released on two islands in Auckland’s Hauraki Gulf. To assess the suitability of captive-bred founders for species restoration projects, short-term survival, condition, reproductive performance, dispersal and activity patterns, and habitat use were investigated using mark-recapture surveys and radio telemetry over a 12 month period following the release, and comparisons were made between captive-bred and wild-sourced geckos. Captive-bred geckos were encountered more often than wild geckos one year after the release, and had greater increases in body condition index. They also had better overall health, but more partial tail losses. Gravid females from both groups were encountered during the first post-release breeding season and at least 50% of juveniles were encountered alive during the first year. Less than 15% of radio tracked geckos moved further than 100 m away from their release locations. The size of activity areas reduced with time after release. Areas of activity were largest for wild geckos during both radio tracking periods and were much larger than the activity areas of captive-bred geckos during the second radio tracking period. Hoplodactylus duvaucelii did not appear to utilise available habitats randomly and rearing history did not appear to influence habitat use. Flax had considerably high use during both radio tracking periods. Overall, captive-bred geckos performed similarly to their wild counterparts, demonstrating that they are suitable for species restoration projects.
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    Anchoring techniques for translocated Duvaucel's geckos (Hoplodactylus duvaucelii), and the use of cell-foam retreats by lizards and invertebrates : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Science in Conservation Biology at Massey University, Albany, New Zealand
    (Massey University, 2015) Holdom, Alaine
    Conservation management often requires translocations to isolated habitats, and determining the success of such events is reliant on the use of effective post-translocation monitoring (PTM) techniques. Many reptile populations are already difficult to monitor, and post-release dispersal often increases this difficulty. Effective monitoring techniques for nocturnal, semi-arboreal, cryptic lizards are consequently still lacking. Furthermore, very little research has been conducted on the use of anchoring techniques for improving the PTM of lizards by reducing post-release dispersal behaviour. In early 2013, two populations of Duvaucel’s geckos (Hoplodactylus duvaucelii) were translocated to two offshore islands. This provided an excellent opportunity to investigate several aspects relating to the improvement of PTM techniques for this species. I investigated whether two anchoring techniques, i.e. temporary food provision and release into cell-foam retreats (CFRs), can reduce post-release dispersal and encourage CFR usage. Further, I assessed the usefulness of CFRs for the PTM of H. duvaucelii. Additionally, I investigated the usage of CFRs for a range of other lizard species and invertebrates. My research provided evidence that both anchoring techniques can improve the use of CFRs by H. duvaucelii in the short term. However, anchoring effects were not maintained beyond two months after release. While anchoring treatments may have delayed postrelease dispersal behaviour, they did not affect post-release dispersal distances. The study results suggest that CFRs can be a useful PTM tool for H. duvaucelii, particularly shortly after translocation, and also aid in the detection of young. In addition, I demonstrated that CFRs can detect a variety of other lizard and invertebrate species. In conclusion, this research provides valuable information for the improvement of monitoring techniques for cryptic, semi-arboreal lizards, also providing evidence that CFRs can be useful tool for monitoring a range of lizards and invertebrates.
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    Conservation biology of the goldstripe gecko (Hoplodactylus chrysosireticus) and interactions with Duvaucel's gecko (Hoplodactylus duvaucelii) on Mana Island, Cook Strait, New Zealand : a thesis presented in partial fulfilment for the degree of Master of Science in Ecology at Massey University
    (Massey University, 2000) Flannagan, Halema Julien
    The conservation biology of goldstripe geckos (Hoplodactylus chrysosireticus) on Mana Island was considered in two ways. First, by studying the ecology, behaviour and population dynamics of H. chrysosireticus on Mana Island and in Taranaki and second, by assessing their behaviour in the presence of newly introduced Duvaucel's geckos (Hoplodactylus duvaucelii) on Mana Island. The activity patterns of H. chrysosireticus were observed at night and during the day on Mana Island between November 1996 and October 1997. H. chrysosireticus were found to exhibit higher levels of diurnal behaviour than previously thought, with over two-thirds of all animals caught during daylight hours (170 out of 257 individuals; mean catch rate = 2.59 per person hour), a behaviour uncharacteristic of the genus. A female-biased sex ratio (0.53:1 male: female) was found among adult H. chrysosireticus on Mana Island but a male bias (1:0.5 male: female) was observed in the Taranaki population. This could be due either to a female-specific behaviour making them more catchable and hence taken more frequently by predators on the mainland, or to the effect of stochastic processes working on a small population. Growth curve estimations showed H. chrysosireticus is slow growing and long-lived, reaching breeding age at around five years. Population size estimates for the main sub-population on Mana Island generated an estimate of 90 (95%C.I 70-136) animals, less than half (200-300) that arising from a survey of the same area in 1993 (200-300) using different survey and calculation methods. Juvenile mortality was high (63% estimate) in the first year and overall population growth slow. The geckos showed high site fidelity with over 90% moving less than 5m from their original point of capture. Population growth on Mana Island is slow despite the absence of mammalian predators, raising serious questions about the security of the remaining mainland populations. Two sets of simultaneous cage and enclosure experiments, designed to observe interactions between H. chrysosireticus and H. duvaucelii were conducted on Mana Island between December 1997 and February 1998. H. chrysosireticus were observed to increase their activity during the day in flax (F2,13 P=0.0040) and climb more in manuka (F2,5 P=0.0450) when in the presence of H. duvaucelii. H. duvaucelii also appear to have preyed upon young H. chrysosireticus when in close contact. The implications of introducing H. duvaucelii to Mana Island and future conservation measures for H. chrysosireticus are discussed.
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    Shelter aggregations, social behaviour, and seasonal plasma corticosterone levels in captive and wild Duvaucel's geckos, Hoplodactylus duvaucelii : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Ecology at Massey University, Albany, New Zealand
    (Massey University, 2010) Barry, Manuela
    The development of effective conservation management strategies is reliant on a thorough understanding of the basic biology and life history of the species of concern. New Zealand’s endemic herpetofauna species have undergone severe range contractions since human arrival due to habitat modifications and predation by introduced mammalian pests. Current conservation management practice involves the eradication of such pests as well as the restoration of habitat involving native species reintroductions. Albeit these conservation attempts, detailed information on physiology, ecology and behaviour of most New Zealand’s lizards is scarce, including the Duvaucel’s gecko (Hoplodactylus duvaucelii). In recent years, several H. duvaucelii have been translocated to islands within their historical range as part of restoration projects and in 2006/7 a captive breeding‐for‐release programme has been established. This provided an excellent opportunity to explore some fundamental aspects of H. duvaucelii’s basic physiology and behavioural ecology. I investigated seasonal plasma corticosterone concentrations of captive and wild geckos in relation to several physiological and ecological factors to enhance our understanding of natural fluctuations of seasonal hormone patterns. Such information can aid in evaluating stress related changes in hormone patterns of individuals and populations, which is particularly relevant for the captive management. I compared plasma steroid hormone patterns of captive geckos from a breeding colony with their wild source population over several seasons to assess whether captive lizards suffered from chronic stress, which could compromise their wellbeing and the fitness of future offspring. Further, I explored several aspects of H. duvaucelii’s social behaviour, including diurnal shelter aggregations, scent communication and social interactions using experimental and exploratory studies on captive and wild geckos. The hormone study provided evidence that H. duvaucelii are suitable for captive breeding as they seem to have adapted well to captivity and did not show a chronic elevation of stress hormone levels. Moreover, my research has shown that H. duvaucelii are essentially social lizards that form shelter aggregations year‐round. Adults showed a high tolerance of juveniles in their diurnal shelters and geckos were able to detect and discriminate scents from conspecifics in several social contexts. These social traits as well as the year‐round occurrence of male‐female pairs combined with H. duvaucelii’s life history traits suggest that this species may possess a social system of high complexity. In conclusion, this dissertation provides a foundation for future research and delivers the first insight into the social behaviour and basic endocrinology of this New Zealand endemic lizard.
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    Ovariectomy as treatment for ovarian bacterial granulomas in a Duvaucel's gecko (Hoplodactylus duvaucelii)
    (Taylor & Francis, 18/06/2015) Barry M; Le Souëf AT; Brunton DH; Jakob-Hoff R; Jackson B
    CASE HISTORY: An adult female Duvaucel’s gecko (Hoplodactylus duvaucelii) from a threatened species breeding programme presented due to a prolonged gestation period and distended abdomen. CLINICAL AND PATHOLOGICAL FINDINGS: The gecko was in lean body condition with an irregularly-shaped, firm mass in the coelomic cavity. Radiographically there was a diffuse radioopacity within the coelomic cavity with cranial displacement of the right lung field. Ultrasonography revealed a round homogenous abdominal mass of medium echogenicity with an echogenic capsule. Haematology showed a leucocytosis with a moderate left shift in heterophils and toxic changes. Bilateral ovariectomy was performed to remove two ovarian granulomas and Salmonella enterica subspecies houtenae (IV) was cultured from the ovarian tissue. The gecko recovered well from the surgery, regained weight and remained in good health 3 years following the surgery. DIAGNOSIS: Pre-ovulatory stasis and ovarian granulomas associated with infection with Salmonella enterica subsp. houtenae. CLINICAL RELEVANCE: The surgery described in this case resulted in recovery of the gecko, which despite its loss of reproductive capability is of value as an education animal. This is the first report of pre-ovulatory stasis and ovarian granulomas associated with infection with Salmonella enterica in a Duvaucel’s gecko and is also the first reported case of pre-ovulatory stasis in a viviparous lizard species. The case adds to knowledge regarding potential reproductive pathology in lizards, which is particularly important information for managers of captive lizard breeding programmes.