Utilization of passive sonic telemetry as indicators of movement and nesting of the Northern Diamondback Terrapin (Malaclemys terrapin terrapin)

Numerous anthropogenic factors pose serious threats to estuarine ecosystems and the organisms inhabiting them. Bulkheading (i.e., construction of shoreline walls), dredging, boating, shoreline development, over-harvesting, and pollution are some of the major human impacts to estuaries in North America. The diamondback terrapin (Malaclemys terrapin) is an ideal species for determining the effects of human impacts to estuarine wildlife, because their habitat use and behavior uniquely utilize both land and aquatic habitats that comprise estuaries. The objective of this study is to determine the home range and nest site selection of diamondback terrapins in relation to anthropogenic impacts in Barnegat Bay Estuary, New Jersey. We will use passive sonic telemetry technology and multiple Submersible Underwater Receivers (SURs) to remotely track free-ranging terrapins throughout the Bay. We will position SURs in arrays throughout areas of the Bay where we have marked terrapins over the last three years to monitor the movements of individual terrapins. Fifteen terrapins will be outfitted with sonic transmitters per site, which will send signals to the SUR when terrapins are within range. Frequency, date, and time of signal reception will be logged remotely by each SUR. From these data we will determine the individual terrapin whose signal was received, and movements of individuals throughout the monitored areas. Gravid (i.e., egg-bearing) females will be closely monitored to determine the nest site(s) used. Reproductive success of nests will be determined for each monitored female. Wherever possible we will determine the cause(s) of nest failure. Our study will be critical in determining the direct and indirect effects of anthropogenic impacts to terrapins in areas of known high terrapin densities. These findings will aid in management decisions regarding both aquatic (e.g., boat) and land (e.g., beach) uses in relation to ensuring the viability of wildlife resources within the Barnegat Bay Estuary

Investigating differences in population recovery rates of two sympatrically nesting sea turtle species

This is the final version. Available on open access from Wiley via the DOI in this recordData Availability Statement: Data are available from corresponding author upon reasonable request.Estimating life‐history traits and understanding their variation underpins the management of long‐lived, migratory animals, while knowledge of recovery dynamics can inform the management of conservation‐dependent species. Using a combination of nest counts and individual‐based life‐history data collected since 1993, we explore the drivers underlying contrasting population recovery rates of sympatrically nesting loggerhead (Caretta caretta) and green (Chelonia mydas) turtles in North Cyprus. We found that nest counts of loggerhead and green turtles from 28 beaches across the island increased by 46% and 162%, respectively over the past 27 years. A Bayesian state‐space model revealed that, at our individual‐based monitoring site, nesting of green turtles increased annually at four times the rate of that of loggerhead turtles. Furthermore, we found that loggerhead turtles nesting at the individual‐based monitoring site had stable reproductive parameters and average adult survival for the species and are the smallest breeding adults globally. Based on results from multiple matrix model scenarios, we propose that higher mortality rates of individuals in all age classes (likely driven by differences in life history and interaction with fisheries), rather than low reproductive output, are impeding the recovery of this species. While the increase in green turtles is encouraging, the Mediterranean population is estimated to have around 3,400 adults and is restricted to the Eastern Basin. The recovery of loggerhead turtles is likely to be compromised until mortality rates in the region are adequately quantified and mitigated. As survival of immature individuals is a powerful driver for sea turtle population numbers, additional efforts should target management at pelagic and neritic foraging areas. Understanding threats faced by immature life stages is crucial to accurately parameterise population models and to target conservation actions for long‐lived marine vertebrates

Geniculo-Cortical Projection Diversity Revealed within the Mouse Visual Thalamus

This is the final version of the article. It was first available from PLOS via http://dx.doi.org/10.1371/journal.pone.0144846All dLGN cell co-ordinates, V1 injection sites, dLGN boundary coordinates, experimental protocols and analysis scripts are available for download from figshare at https://figshare.com/s/36c6d937b1844eec80a1.The mouse dorsal lateral geniculate nucleus (dLGN) is an intermediary between retina and primary visual cortex (V1). Recent investigations are beginning to reveal regional complexity in mouse dLGN. Using local injections of retrograde tracers into V1 of adult and neonatal mice, we examined the developing organisation of geniculate projection columns: the population of dLGN-V1 projection neurons that converge in cortex. Serial sectioning of the dLGN enabled the distribution of labelled projection neurons to be reconstructed and collated within a common standardised space. This enabled us to determine: the organisation of cells within the dLGN-V1 projection columns; their internal organisation (topology); and their order relative to V1 (topography). Here, we report parameters of projection columns that are highly variable in young animals and refined in the adult, exhibiting profiles consistent with shell and core zones of the dLGN. Additionally, such profiles are disrupted in adult animals with reduced correlated spontaneous activity during development. Assessing the variability between groups with partial least squares regression suggests that 4?6 cryptic lamina may exist along the length of the projection column. Our findings further spotlight the diversity of the mouse dLGN?an increasingly important model system for understanding the pre-cortical organisation and processing of visual information. Furthermore, our approach of using standardised spaces and pooling information across many animals will enhance future functional studies of the dLGN.Funding was provided by a Wellcome Trust grant jointly awarded to IDT and SJE (083205, www.wellcome.ac.uk), and by MRC PhD Studentships awarded to MNL and ACH (http://www.mrc.ac.uk/)

Global research priorities for sea turtles : informing management and conservation in the 21st century

Over the past 3 decades, the status of sea turtles and the need for their protection to aid population recovery have increasingly captured the interest of government agencies, non-governmental organisations (NGOs) and the general public worldwide. This interest has been matched by increased research attention, focusing on a wide variety of topics relating to sea turtle biology and ecology, together with the interrelations of sea turtles with the physical and natural environments. Although sea turtles have been better studied than most other marine fauna, management actions and their evaluation are often hindered by the lack of data on turtle biology, human–turtle interactions, turtle population status and threats. In an effort to inform effective sea turtle conservation a list of priority research questions was assembled based on the opinions of 35 sea turtle researchers from 13 nations working in fields related to turtle biology and/or conservation. The combined experience of the contributing researchers spanned the globe as well as many relevant disciplines involved in conservation research. An initial list of more than 200 questions gathered from respondents was condensed into 20 metaquestions and classified under 5 categories: reproductive biology, biogeography, population ecology, threats and conservation strategies

Constraints of bioenergetics on the ecology and distribution of vertebrate ectotherms

The constraints of bioenergetics on the ecology and distribution of vertebrate ectotherms were quantified. During this project we conducted studies: to determine the role of incubation temperature on the post-hatching growth rate of the snapping turtle, Chelydra serpentina; to establish the rate of energy expenditure of the slider turtle, Trachemys scripta, in the field; to determine the field metabolic rates, body temperatures and selected microclimates of the box turtle, Terrapene carolina, and to measure the effect of diet type on the consumption rate, digestion rate and digestive efficiency of adult T. scripta. We also completed our research on the three-dimensional bioenergetic climate space for freshwater turtles

Alien plant threatens Nile crocodile (Crocodylus niloticus) breeding in Lake St. Lucia, South Africa

We observed that the majority of Lake St. Lucia's nesting Nile crocodiles (Crocodylus niloticus) selected open, sunny, sandy areas in which to deposit their eggs. Nests were only found in shaded sites in the Mpate River breeding area and these nests were shaded primarily by an alien plant. Chromolaena odorata. Soil temperatures of shaded sites at 25-cm depth, were on average 5.0-6.0°C cooler than in sunny sites at the same depth. They were well below the pivotal temperature for nests of St. Lucia's Nile crocodiles, i.e. they probably produced a female-biased sex ratio, and may have prevented embryonic development altogether. Many females abandoned nesting sites when they encountered the fibrous root mats of Chromolaena odorata while digging egg chambers. When additional nesting sites were experimentally created, the percent of sites utilized increased, indicating that suitable nesting sites were in short supply. This alien plant is posing a very serious threat to the continued survival of the Nile crocodile in Greater St. Lucia Wetland Park, and unless immediate action is taken, a female-biased sex ratio will result in eventual extirpation of the species from this recently acclaimed Word Heritage Site. © 2001 Elsevier Science Ltd.Articl

Utilization of Passive Sonic Telemetry as Indicators of Movement and Nesting of the Northern Diamondback Terrapin (Malaclemys terrapin terrapin)

Numerous anthropogenic factors pose serious threats to estuarine ecosystems and the organisms inhabiting them. Bulkheading (i.e., construction of shoreline walls), dredging, boating, shoreline development, over-harvesting, and pollution are some of the major human impacts to estuaries in North America. The diamondback terrapin (Malaclemys terrapin) is an ideal species for determining the effects of human impacts to estuarine wildlife, because their habitat use and behavior uniquely utilize both land and aquatic habitats that comprise estuaries. The objective of this study is to determine the home range and nest site selection of diamondback terrapins in relation to anthropogenic impacts in Barnegat Bay Estuary, New Jersey. We will use passive sonic telemetry technology and multiple Submersible Underwater Receivers (SURs) to remotely track free-ranging terrapins throughout the Bay. We will position SURs in arrays throughout areas of the Bay where we have marked terrapins over the last three years to monitor the movements of individual terrapins. Fifteen terrapins will be outfitted with sonic transmitters per site, which will send signals to the SUR when terrapins are within range. Frequency, date, and time of signal reception will be logged remotely by each SUR. From these data we will determine the individual terrapin whose signal was received, and movements of individuals throughout the monitored areas. Gravid (i.e., egg-bearing) females will be closely monitored to determine the nest site(s) used. Reproductive success of nests will be determined for each monitored female. Wherever possible we will determine the cause(s) of nest failure. Our study will be critical in determining the direct and indirect effects of anthropogenic impacts to terrapins in areas of known high terrapin densities. These findings will aid in management decisions regarding both aquatic (e.g., boat) and land (e.g., beach) uses in relation to ensuring the viability of wildlife resources within the Barnegat Bay Estuary

Utilization of Passive Sonic Telemetry as Indicators of Movement and Nesting of the Northern Diamondback Terrapin (Malaclemys terrapin terrapin)

Numerous anthropogenic factors pose serious threats to estuarine ecosystems and the organisms inhabiting them. Bulkheading (i.e., construction of shoreline walls), dredging, boating, shoreline development, over-harvesting, and pollution are some of the major human impacts to estuaries in North America. The diamondback terrapin (Malaclemys terrapin) is an ideal species for determining the effects of human impacts to estuarine wildlife, because their habitat use and behavior uniquely utilize both land and aquatic habitats that comprise estuaries. The objective of this study is to determine the home range and nest site selection of diamondback terrapins in relation to anthropogenic impacts in Barnegat Bay Estuary, New Jersey. We will use passive sonic telemetry technology and multiple Submersible Underwater Receivers (SURs) to remotely track free-ranging terrapins throughout the Bay. We will position SURs in arrays throughout areas of the Bay where we have marked terrapins over the last three years to monitor the movements of individual terrapins. Fifteen terrapins will be outfitted with sonic transmitters per site, which will send signals to the SUR when terrapins are within range. Frequency, date, and time of signal reception will be logged remotely by each SUR. From these data we will determine the individual terrapin whose signal was received, and movements of individuals throughout the monitored areas. Gravid (i.e., egg-bearing) females will be closely monitored to determine the nest site(s) used. Reproductive success of nests will be determined for each monitored female. Wherever possible we will determine the cause(s) of nest failure. Our study will be critical in determining the direct and indirect effects of anthropogenic impacts to terrapins in areas of known high terrapin densities. These findings will aid in management decisions regarding both aquatic (e.g., boat) and land (e.g., beach) uses in relation to ensuring the viability of wildlife resources within the Barnegat Bay Estuary

Thermal benefits of melanism in cordylid lizards: a theoretical and field test

The hypothesis that low skin reflectance (melanism) provides an advantage for thermoregulation under cold conditions has received mixed support in ectothermic vertebrates. We selected a model system, three allopatric closely related species of cordylid lizards that differ in skin reflectance, to test this hypothesis. Cordylus niger and Cordylus oelofseni are melanistic and inhabit peninsular and montane areas, respectively, whereas Cordylus cordylus is more widespread and inhabits low inland areas. By combining theoretical, experimental, and field data on these species, we demonstrate that the difference in body temperature (Tb) between melanistic and non-melanistic lizards under ecologically relevant climate variation ranged from 0° to 2°C. Despite its small magnitude, however, the faster heating rate and higher Tb of melanistic species relative to non-melanistic species conferred an advantage under cold conditions. Comparison of habitat thermal quality (de) and thermal accuracy (db) across species indicated that, in winter, melanism conferred the greatest advantage during small windows of thermal opportunity. This finding was most pronounced for C. oelofseni, which is most constrained by cold temperatures in its habitat. By contrast, due to their rock-dwelling habits, melanistic and non-melanistic species benefited from rock refugia in summer, giving similar levels of thermoregulatory effectiveness across species, regardless of skin reflectance. This study therefore demonstrates that skin reflectance variation across cordylids has significant effects on their thermal balance. Furthermore, studies investigating the role of varying skin reflectance in field populations and species should incorporate fine and broad temporal scales (daily, monthly, and seasonal), environmental variability, and cost–benefit trade-offs of thermoregulation.Centre of Excellence for Invasion Biolog