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    Population dynamics and behavioural ecology of two isolated populations of the Floreana mockingbird : laying the basis for its reintroduction : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Conservation Biology at Massey University, Auckland, New Zealand
    (Massey University, 2021) Rodriquez Reyes, Enzo Marcelo
    Translocations are one of the most important conservation actions in the recovery of endangered species, these imply the movement of live individuals from one area to another. To ensure the success of translocations, different logistics and species-specific ecological factors need to be considered. Since the early 2000’s, there have been calls to reintroduce the endangered cooperative breeding Floreana mockingbird, to Floreana Island (Galápagos Archipelago) where they became locally extinct due to habitat loss and invasive species. The species currently inhabiting two small islets off the coast of Floreana with no recent history of connection between populations. However, our understanding of reintroduction strategies for the mockingbird is based on monogamous breeding species, not on cooperative breeding species. In this thesis, I explored demographic and behavioural aspects of the species that might facilitate the reintroduction to Floreana. Firstly, I described a non-invasive method that will help will the correct sexing identification and monitoring of Floreana mockingbirds. Furthermore, I assessed the probability of survival of the species using capture-mark-recapture (CMR) models and the influence of precipitation on the survival rate, recruitment of individuals, and population growth. Overall, the population seem to be stable with a slight decrease in one of the populations. Additionally, I explored ecological factors such as vocalization and sociality. I investigated the hypothesis of possible differences in vocalisations between individuals from the two remnant populations. I found an acoustic divergence between populations that could be explained by the influence of cultural drift and morphological differentiation as an effect of isolation, lack of gene flow, and cultural exchange. Finally, I investigated the social structure of the Floreana mockingbird and the probability of group disruption during translocations. I found that mockingbirds live in a highly transitive hierarchy and that the dominance networks are explained by the age and social status of the individuals. Moreover, the network simulations showed that inadequate harvesting could increase the probability of group disruption in the new area of translocations. My research will help develop a reintroduction strategy for the species to Floreana Island and it will assist the Galápagos National Park to reach a major conservation milestone for the species.
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    Conservation status and demographics of the Galapagos land iguana (Conolophus subcristatus) in the Galapagos Islands, Ecuador : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Natural Science in Conservation Biology, Massey University, New Zealand
    (Massey University, 2019) Kumar, Kirtana
    In conservation biology, understanding the basic demography of populations across their range, provides opportunities to identify and prioritise management actions to improve the conservation of both, populations and of the species as a whole. The Galapagos land iguana or land iguana (Conolophus subcristatus) (endemic to the Galapagos Islands), is an ideal model to explore these ideas and to generate information that can assist its conservation. Currently, the species is classified as IUCN: Vulnerable. Land iguana populations are threatened by introduced species and habitat loss but the intensity of these threats varies between populations. The population sizes across the species range are partially known and suspected to relate to the presence/absence of introduced predators. Although demographic trends are virtually unknown, it is suspected that populations in disturbed areas have a lower recruitment of juveniles and limited population growth. Overall, these gaps in knowledge represent a challenge to a formal evaluation of the species’ conservation status. Historically, translocation of land iguanas to predator-free or predator-managed sites in the Galapagos Islands has played an important role for its conservation. Since the 1970s there have been calls for translocating land iguanas to Santiago Island, considered to harbour one of the largest land iguana populations until the early 1900s. Although the mechanism for the extinction of the Santiago Island population is not understood, it is most likely linked to habitat changes driven by humans and the effects of introduced predators, which are common denominators in significant iguana population declines on other islands around the world. Since the early 2000s, introduced predators have been eradicated on Santiago Island, and the possibility of reintroducing land iguanas there has resurfaced with greater intensity. While the habitat on Santiago Island is considered suitable for land iguanas, and the expertise to handle and transfer these organisms exists there are missing gaps in knowledge in particular: is the size of historically translocated populations comparable to undisturbed populations? What are the current population sizes of land iguana populations? and what are the effects of introduced predators on land iguana populations? This thesis addresses these gaps in land iguana demography by providing an update of the current conservation status, estimates of population size and an analysis of the effects of feral cats using historical data. I examined the effects of feral cats on two populations by comparing historical demographic data from cat-absent and cat-present populations. I found cat-present populations exhibited significantly different population structure and morphology to cat-absent populations, including significantly lower juvenile percentage indicating reduced juvenile recruitment as a result of juvenile depredation . Further, I studied a translocated population of land iguanas (North Seymour) and the most undisturbed land iguana population in one of the most active volcanoes worldwide; Fernandina Island. I estimate and compare population size to assist the planning of a reintroduction of the species to Santiago Island. Finally, I review the IUCN status of the species and conclude that the Vulnerable status is justified, primarily due to its limited geographic range and projected population decline. Four weeks before the completion of this thesis, the Directorate of the Galapagos National Park, Island Conservation and Massey University completed a transfer of over 2000 land iguanas to Santiago Island based on the information provided in this document. Although I could not incorporate the posttranslocation monitoring of land iguanas as part of my thesis, I discuss future research needs that will contribute to the restoration of Santiago Island, and the conservation of land iguanas across their range.
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    Ecology of sharks and human attitudes towards shark conservation in the Galapagos Marine Reserve : 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, 2018) Acuña Marrero, David
    In this thesis, I used a multi-disciplinary approach to study both the spatial ecology of coastal sharks and human attitudes towards sharks at the Galapagos Marine Reserve (GMR). Benthic and pelagic baited remote underwater stereo-video systems recorded coastal shark assemblages that displayed high spatial variation, with the relative importance of environmental and biological drivers differing among shark species according to their mobility. Telemetry data (both acoustic and satellite) from tagged tiger sharks (Galeocerdo cuvier) showed a high degree of philopatry, with movements of adult tiger sharks concentrating at the most important nesting areas for sea turtles at the GMR. Using diver-operated stereo-video systems (DOVs) I demonstrated that non-instantaneous surveys yield estimates of shark densities that can almost double the ones obtained from instantaneous surveys. Furthermore, I proposed a new methodological approach to study attitudes towards sharks that proved to be reliable and informative, showing that attitudes were shaped by a range of psychological factors, such as aesthetics, and also by the socio-economic context of individual respondents. Strong correlations were found between attitudes and behavioural responses, such as tolerance or support for shark protection. In conclusion, I demonstrated that sharks at the GMR have species-specific and size-specific spatial requirements for particular habitats and food resources. Indeed, the presence of a predictable source of prey and suitable habitats at the GMR might reduce the spatial extent of the potential areas used by large and highly mobile shark species, such as tiger sharks, thereby enhancing the potential effectiveness of the GMR for their protection. I also propose the use of non-instantaneous DOV surveys to provide more accurate estimates of shark densities than underwater visual techniques. In addition, the multivariate methods used here for the first time to study human perspectives on sharks allowed me to identify specific attitudes and associated factors having the greatest influence on human behaviours towards shark conservation. In summary, with mounting anthropogenic pressures on shark populations, this thesis provides timely and critical information for the global objective of identifying effective strategies for the management and conservation of sharks to ensure their long-term survival.
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    Demography and conservation of the Floreana racer (Pseudalsophis biserialis biserialis) on Gardner-By-Floreana and Champion Islets, Galápagos Islands, Ecuador : thesis submitted in partial fulfillment of the requirements for the degree of Master of Natural Science
    (Massey University, 2017) Christian, Eli J
    The Floreana Racer (Pseudalsophis biserialis biserialis) is a mediumsized colubrid endemic to the islets of Gardner-by-Floreana and Champion off the coast of Floreana Island, in the South of the Galápagos Archipelago. The subspecies was historically abundant on Floreana Island, as indicated by subfossil remains, however is has since been extinct there since the late 1800’s as a result of the effects of large-scale habitat modification, fires and the introduction of rats and cats. I conducted the first field study on the population size, inter-island morphological variability and the diet of the Floreana racer on the two islets where the species occurs as a first step towards the translocation of Floreana racers to Floreana Island. Fieldwork took place over 30 days between November 2015 and January 2017. With the assistance of eight colleagues and volunteers I conducted daylight searches for Floreana racers yielding a total of 123 individuals, 20 on Champion and 103 on Gardner-by-Floreana. Of these 119 individuals were marked with unique PITTags. I also conducted a mark-recapture estimate of population size on both islets based on 17 recaptures. The resulting estimate of the global population of the subspecies is approximately 3088 individuals (Champion 209 snakes; Gardner-by-Floreana: 2879 snakes). I also investigated the diet of Floreana racers via analysis of faecal samples from 29 individuals. The most common prey items are lava lizards (Microllophus grayii), followed by the Floreana gecko (Phyllodactyllus baueri). Lastly I discuss the conservation status of the subspecies and future areas of research and management to advance the knowledge, and conservation status of the Floreana Racer.