Conservation status of New Zealand reptiles, 2012

Abstract: The conservation status of all known New Zealand reptile taxa was reassessed using the New Zealand Threat Classification System (NZTCS). A full list is presented, along with a statistical summary and brief notes on the most important changes. This list replaces all previous NZTCS lists for reptiles. Summary: Hitchmough et al. (2010) presented results of the first known complete audit (carried out in 2009) of the conservation status of New Zealand reptiles, including marine migrant and vagrant species, and introduced species—a total of 109 taxa. The conservation status of these taxa was assessed using New Zealand Threat Classification System (NZTCS) criteria (Townsend et al. 2008). We have repeated this status assessment 3 years later, as suggested by Townsend et al. (2008). The categories, criteria and process were identical between the two listings, and most of the panel members (the authors of Hitchmough et al. 2010 and this document) were the same. We assessed the status of 110 taxa, including 45 unnamed entities (41% of the total, and 45% of the native lizards, the group to which all the undescribed entities belong). One additional species of Vagrant sea snake (the blue-lipped sea krait Laticauda laticaudata) has been recorded in New Zealand since the publication of Hitchmough et al. (2010). No other new taxa were added and circumscriptions of all taxa were unchanged. There were some name changes between the two assessments (Table 1) resulting from the formal descriptions of some skink species previously listed as tag-named Taxonomically Indeterminate entities (Chapple et al. 2011), the elevation of the two former subspecies of Naultinus elegans to full species and the splitting of the gecko genus Hoplodactylus into six genera (Neilson et al. 2011). There are now no recognised or proposed subspecies of New Zealand reptiles—all described taxa are full species and all undescribed entities are considered to be likely species. Authors: Rod Hitchmough, Peter Anderson, Ben Barr, Jo Monks, Marieke Lettink, James Reardon, Mandy Tocher and Tony Whitake

Thermal Transients in District Heating Systems

Heat fluxes in a district heating pipeline systems need to be controlled on the scale from minutes to an hour to adjust to evolving demand. There are two principal ways to control the heat flux - keep temperature fixed but adjust velocity of the carrier (typically water) or keep the velocity flow steady but then adjust temperature at the heat producing source (heat plant). We study the latter scenario, commonly used for operations in Russia and Nordic countries, and analyze dynamics of the heat front as it propagates through the system. Steady velocity flows in the district heating pipelines are typically turbulent and incompressible. Changes in the heat, on either consumption or production sides, lead to slow transients which last from tens of minutes to hours. We classify relevant physical phenomena in a single pipe, e.g. turbulent spread of the turbulent front. We then explain how to describe dynamics of temperature and heat flux evolution over a network efficiently and illustrate the network solution on a simple example involving one producer and one consumer of heat connected by "hot" and "cold" pipes. We conclude the manuscript motivating future research directions.Comment: 31 pages, 7 figure

Conservation status of the world's skinks (Scincidae): taxonomic and geographic patterns in extinction risk

Our knowledge of the conservation status of reptiles, the most diverse class of terrestrial vertebrates, has improved dramatically over the past decade, but still lags behind that of the other tetrapod groups. Here, we conduct the first comprehensive evaluation (~92% of the world's ~1714 described species) of the conservation status of skinks (Scincidae), a speciose reptile family with a worldwide distribution. Using International Union for Conservation of Nature (IUCN) criteria, we report that ~20% of species are threatened with extinction, and nine species are Extinct or Extinct in the Wild. The highest levels of threat are evident in Madagascar and the Neotropics, and in the subfamilies Mabuyinae, Eugongylinae and Scincinae. The vast majority of threatened skink species were listed based primarily on their small geographic ranges (Criterion B, 83%; Criterion D2, 13%). Although the population trend of 42% of species was stable, 14% have declining populations. The key threats to skinks are habitat loss due to agriculture, invasive species, and biological resource use (e.g., hunting, timber harvesting). The distributions of 61% of species do not overlap with protected areas. Despite our improved knowledge of the conservation status of the world's skinks, 8% of species remain to be assessed, and 14% are listed as Data Deficient. The conservation status of almost a quarter of the world's skink species thus remains unknown. We use our updated knowledge of the conservation status of the group to develop and outline the priorities for the conservation assessment and management of the world's skink species

The conservation status of the world’s reptiles

Effective and targeted conservation action requires detailed information about species, their distribution, systematics and ecology as well as the distribution of threat processes which affect them. Knowledge of reptilian diversity remains surprisingly disparate, and innovative means of gaining rapid insight into the status of reptiles are needed in order to highlight urgent conservation cases and inform environmental policy with appropriate biodiversity information in a timely manner. We present the first ever global analysis of extinction risk in reptiles, based on a random representative sample of 1500 species (16% of all currently known species). To our knowledge, our results provide the first analysis of the global conservation status and distribution patterns of reptiles and the threats affecting them, highlighting conservation priorities and knowledge gaps which need to be addressed urgently to ensure the continued survival of the world’s reptiles. Nearly one in five reptilian species are threatened with extinction, with another one in five species classed as Data Deficient. The proportion of threatened reptile species is highest in freshwater environments, tropical regions and on oceanic islands, while data deficiency was highest in tropical areas, such as Central Africa and Southeast Asia, and among fossorial reptiles. Our results emphasise the need for research attention to be focussed on tropical areas which are experiencing the most dramatic rates of habitat loss, on fossorial reptiles for which there is a chronic lack of data, and on certain taxa such as snakes for which extinction risk may currently be underestimated due to lack of population information. Conservation actions specifically need to mitigate the effects of human-induced habitat loss and harvesting, which are the predominant threats to reptiles