The successful elimination of Cane toads, <Emphasis Type="Italic">Bufo marinus</Emphasis>, from an island with breeding habitat off Bermuda

The 6.5 Ha Nonsuch island nature reserve in Castle harbour, Bermuda, under restoration as a “Living museum” of Bermuda’s pre-colonial terrestrial flora and fauna since 1962, was unexpectedly compromised by the colonization of a manmade freshwater pond by the invasive Cane toad Bufo marinus, which managed to cross a 175 m seawater barrier isolating the island. The toad was considered to pose a threat to the endemic Skink, for which Nonsuch is a key sanctuary, and to the burrow nesting Bermuda petrel or Cahow, which was about to be translocated to that larger island in order to establish a colony safe from the global warming threat of sealevel rise. A non-lethal method of removing the toads was devised through installation of a toad barrier around the freshwater pond, constructed of robust high density polyethylene (HDPE). Toads outside the barrier were no longer able to breed and were captured and removed by night searches over a five year period as they piled up against it. Removal of the breeding population inside the barrier was only possible by capturing all individuals resulting from each spawning before they could reach breeding age. This also took 5 years despite the small size (0.06 Ha) of the pond. A total of 1,244 toads were removed to Bermuda’s mainland. As breeding age is attained in 2 years the collection total for the first 2 years provided an approximation of the population density on the island before removal began (~80 per Ha). Although the immigration rate to Nonsuch is estimated to be less than one per year, this still requires maintaining the barrier as a permanent fixture. As future immigrants can be fairly quickly intercepted, the toad is now essentially extaxic on Nonsuch. This is the first published report of a successful eradication of the species from an island with breeding habitat.     

The effects of density,rainfall and environmental temperature on body condition and fecundity in the common toad,Bufo bufo

The body length and body weight of all adult common toads (Bufo bufo) breeding at a pond in south Dorset were measured between 1983 and 1993. Each toad was placed into one of four categories depending on its sex and whether it was either a first time breeder or an animal that had previously bred. The body condition of each male and female toad for each year was compared with the average body condition of all the male and female toads captured over the 11 years of the study so that between-year differences in condition could be detected. Changes in body condition were compared with changes in body condition were compared with changes in toad density, rainfall and climatic temperature during the previous summer (March–September), during hibernation (October–February) and during the month preceding the start of spawning. During the study there was a decline in the body condition of all toad categories and these changes were significantly correlated with changes in toad density and climatic temperature. Toads were also more likely to enter hibernation in poor condition following a hot dry summer than after either cool wet or hot wet summers. Body condition explained 41% of the size-specific variation in fecundity.     

Sea surface temperatures and coral reef bleaching off La Parguera, Puerto Rico (northeastern Caribbean Sea)

 Much recent attention has been given to coral reef bleaching because of its widespread occurrence, damage to reefs, and possible connection to global change. There is still debate about the relationship between temperature and widespread bleaching. We compared coral reef bleaching at La Parguera, Puerto Rico to a 30-y (1966–1995) record of sea surface temperature (SST) at the same location. The last eight years of the La Parguera SST record have all had greater than average maximum temperatures; over the past 30 y maximum summer temperature has increased 0.7 °C. Coral reef bleaching has been particularly frequent since the middle 1980s. The years 1969, 1987, 1990, and 1995 were especially noteworthy for the severity of bleaching in Puerto Rico. Seven different annual temperature indices were devised to determine the extent to which they could predict severe coral bleaching episodes. Three of these, maximum daily SST, days >29.5 °C, and days >30 °C predict correctly the four years with severe bleaching. A log-log linear relationship was found between SST and the number of days in a given year above that SST at which severe coral beaching was observed. However, the intra-annual relationship between temperature and the incidence of bleaching suggests that no one simple predictor of the onset of coral bleaching within a year may be applicable. Accepted: 17 March 1998     

Seasonal changes in the migratory behaviour of the toad Bufo bufo: direction and magnitude of movements

Summary The migratory behaviour of the toad Bufo bufo was studied from February 1985 to April 1986 in the submontane region of Bavaria, West Germany. Toads were fitted with a mechanical tracking device to record individual paths of migration. Three aspects of migratory behaviour were quantified: orientation in relation to the breeding site, straightness of path, and locomotory activity. The annual activity period began with migration from the hibernation sites to the breeding pond in April. The paths went straight towards the breeding pond independent of the distance (70–420 m). During the period of oviposition the preference for the breeding site direction vanished and toads moved away from the breeding pond, but in less straight paths than before. In summer migratory activity decreased considerably and was restricted to small areas, the home ranges, at distances of 55–1600 m from the natal breeding pond. The straightness of path was rather low, because toads often returned to their starting points. During rainy nights toads occasionally left their home ranges for extensive excursions. In autumn most toads again migrated towards the breeding pond, but paths were significantly less straight and direct than in spring. However, toads stopped before reaching the breeding pond and hibernated in holes or under the leaf layer. The mortality rate of tracked toads was about 45%. The relative influence of 17 environmental variables on locomotory activity was evaluated by principal component analysis and stepwise multiple regression. Temperature at night and rainfall variables accounted for significant amounts of variance, whereas temperature by day, air humidity, and atmospheric pressure showed no correlation. Activity decreased if temperature approached 0° C or after long periods without rainfall. Within a certain range of tolerance, however, the locomotory activity of the toads was widely independent of environmental factors, indicating that endogeneous factors are more important sources of variation in the migratory behaviour of these toads than commonly assumed.     

Grape harvest and yield responses to inter-annual changes in temperature and precipitation in an area of north-east Spain with a Mediterranean climate

This study presents an analysis of temperature and precipitation trends and their impact on grape harvests in the Penedès region (NE Spain). It includes analyses of maximum, minimum and mean daily temperatures (for both the growing and ripening seasons) and daily rainfall (for the hydrological year, the growing season and each phenological stage) for three observatories in the immediate area. We analysed a series of factors: beginning and end harvest dates; the day on which a given potential alcoholic degree was reached; and yield for several varieties of grape grown in the area in relation to climatic variables. Maximum temperatures increased at all the observatories, with greater values being recorded in recent years (1996–2009) than in previous decades (1960s–2000s): we observed increases in average growing season temperatures of 0.11°C per year for the period 1996–2009 vs 0.04°C per year for the period 1960–2009 at Vilafranca del Penedès. These temperature changes were due mainly to increases in maximum temperatures and an increase in the incidence of extreme heat (number of days with T > 30°C). Crop evapotranspiration also increased significantly during the same period. The Winkler index also increased, so the study area would correspond to region IV according to that climatic classification. There were no significant trends in annual rainfall but rainfall recorded between bloom and veraison decreased significantly at the three observatories, with the greatest decrease corresponding to the period 1996–2009. The dates on which harvests started and ended showed a continuous advance (of between −0.7 and −1.1 days per year, depending on the variety), which was significantly correlated with the average mean and maximum daily growing season temperatures (up to −7.68 days for 1°C increase). Winegrape yield was influenced by the estimated water deficit (crop evapotranspiration minus precipitation) in the bloom-veraison period; this value increased due to a reduction in precipitation and an increase in evapotranspiration. Yield may have been reduced by up to 30 kg/ha for each millimetre increase in the estimated water deficit. Under these conditions, new strategies need to be followed in this area in order to maintain grape quality and yield.     

Mapping the Relative Probability of Common Toad Occurrence in Terrestrial Lowland Farm Habitat in the United Kingdom

Introduction

The common toad (Bufo bufo) is of increasing conservation concern in the United Kingdom (UK) due to dramatic population declines occurring in the past century. Many of these population declines coincided with reductions in both terrestrial and aquatic habitat availability and quality and have been primarily attributed to the effect of agricultural land conversion (of natural and semi-natural habitats to arable and pasture fields) and pond drainage. However, there is little evidence available to link habitat availability with common toad population declines, especially when examined at a broad landscape scale. Assessing such patterns of population declines at the landscape scale, for instance, require an understanding of how this species uses terrestrial habitat.

Methods

We intensively studied the terrestrial resource selection of a large population of common toads in Oxfordshire, England, UK. Adult common toads were fitted with passive integrated transponder (PIT) tags to allow detection in the terrestrial environment using a portable PIT antenna once toads left the pond and before going into hibernation (April/May-October 2012 and 2013). We developed a population-level resource selection function (RSF) to assess the relative probability of toad occurrence in the terrestrial environment by collecting location data for 90 recaptured toads.

Results

The predicted relative probability of toad occurrence for this population was greatest in wooded habitat near to water bodies; relative probability of occurrence declined dramatically > 50 m from these habitats. Toads also tended to select habitat near to their breeding pond and toad occurrence was negatively related to urban environments.     

Reproductive behaviour of wild-living wolves in Białowieża Primeval Forest (Poland)

Characteristics of the reproductive behaviour of wolves (Canis lupus) were studied by radio-tracking and snow-tracking of four packs in Białowieża Primeval Forest (BPF), Poland, in 1995–1999. Signs of mating occurred between 12 January and 22 March. Parturition occurred between 19 April and 12 May, and the denning period lasted for 49–64 days. During that time, wolves used 1–3 den sites, spending on average 27 days at each site. The dens were never reused in consecutive years, but year after year the breeding sites were located in the same parts of the pack’s territory. Ten days before parturition pregnant females reduced their normal mobility by half (from 23 to 13.5 km day⁻¹, on average). During the ten days post-partum, they spent 85% of their time with pups and travelled 3.9 km day⁻¹, only. On days 11–30 after parturition, females spent 74% of their time tending pups and increased their daily movement distance to a mean of 13.3 km. The females resumed full mobility 50–70 days after parturition, which coincides with termination of the weaning process. Anecdotal observations indicated that pups were tended by other pack members while the mother was absent. Compared with the years 1947–1950, in 1995–1999 the breeding season of wolves in BPF occurred two weeks earlier. A possible reason was the 1 to 1.5-degree increase in the mean annual temperature during the last 50 years.     

Investigations into the occurrence of alkaloids in ergot and single sclerotia from the 2007 and 2008 harvests

As a contribution to the occurrence of ergot alkaloids in ergot from German rye and triticale, samples from the 2007 and 2008 harvests were analyzed. Twelve alkaloids—six pairs of main alkaloids and their corresponding epimers—were determined in extracts prepared under alkaline conditions by HPLC with fluorescence detection without preceding purification. The total alkaloid content was found to be 0.03–0.18% in ergot from rye (n = 19) and 0.06–0.22% in ergot from triticale (n = 4), respectively. Furthermore, single sclerotia (n = 40) were investigated in terms of alkaloid content and distributional pattern. The main alkaloids in ergot were ergocristine, ergotamine and ergocornine, although the alkaloid composition was highly variable. Presented in part at the 30th Mykotoxin-Workshop, Utrecht, The Netherlands, April 28–30, 2008     

Long-term within pond variation of egg deposition sites in the agile frog, <Emphasis Type="Italic">Rana dalmatina</Emphasis>

This study presents long-term fluctuation, within pond distribution and mortality of egg masses in a population of Rana dalmatina reproducing in a permanent semi-natural pond in Romania. The average number of egg masses per year was 410 (SD = 114.56, min.-max. = 265–581). The mean spawning duration (days) was 26.72 (SD = 5.53). The egg mass distribution was not constant during the years. The long-term change in the distribution of egg masses can be related to changes in the reed cover (pond variable) and landscape structure, i.e. the presence of the forest and a pasture between the pond and the forest. There was a reduction in the number of dead egg masses during the study period. We suggest that the maintenance of the connectivity with the forest and the variable amount of reed assure the main aquatic and terrestrial habitats for the agile frogs. This will allow agile frogs to shift breeding habitats in this area according to their ecological needs and find safe terrestrial habitats for summering and wintering.     

The impact of future summer temperature on public health in Barcelona and Catalonia,Spain

Several epidemiological studies have reported associations between increases in summer temperatures and risks of premature mortality. The quantitative implications of predicted future increases in summer temperature, however, have not been extensively characterized. We have quantified these effects for the four main cities in Catalonia, Spain (Barcelona, Tarragona, Lleida, Girona). We first used case-crossover analysis to estimate the association between temperature and mortality for each of these cities for the period 1983 to 2006. These exposure–response (ER) functions were then combined with local measures of current and projected changes in population, mortality and temperature for the years 2025 and 2050. Predicted daily mean temperatures were based on the A1B greenhouse gas emission, “business-as-usual” scenario simulations derived from the ENSEMBLES project. Several different ER functions were examined and significant associations between temperature and mortality were observed for all four cities. For these four cities, the age-specific piecewise linear model predicts 520 (95%CI  340, 720) additional annual deaths attributable to the change in temperature in 2025 relative to the average from the baseline period of 1960–1990. For 2050, the estimate increases to 1,610 deaths per year during the warm season. For Catalonia as a whole, the point estimates for those two years are 720 and 2,330 deaths per year, respectively, or about 2 and 3% of the warm season. In comparing these predicted impacts with current causes of mortality, they clearly represent significant burdens to public health in Catalonia.     

Breeding cycle of the Cape petrel Daption capense at Nelson Island, Antarctica

Timing and duration of the breeding cycle of the Cape petrel Daption capense were studied during two breeding seasons (1990/1991 and 1991/1992) at Nelson Island, South Shetland Islands, Antarctica. In 1991/1992 the copulatory period extended over 53 days, with median date and a peak about 28 and 19 days respectively, before the median date of laying. Laying began 85 days after arrival, with mean (= median) date on 2 December (SD = 2.5 days). The distributions of laying, hatching and fledging dates showed a similar degree of synchrony and did not differ between years. Incubation and chick period were equally long (46 days), the former being less variable (coefficient of variation = 2.8% and 4.6%, respectively). Mean completed nesting cycle (92 days) was about 2 days shorter at Nelson Island than elsewhere and tended to shorten as the breeding season progressed. Its mean length represented 86% of the whole nesting period (107 days), which in turn represented 56% of the period of continuous colony attendance. Timing and duration of nesting stages did not differ between colonies or sets of nests subjected to various levels of disturbance. Received: 8 July 1996 / Accepted: 11 November 1996     

Interspecific spawning between Common frogs (Rana temporaria) and Common toads (Bufo bufo)

The interaction between Common frogs (Rana temporaria) and Common toads (Bufo bufo) during the breeding season was studied at a small pond on Portland, Dorset. Although the frogs started and finished spawning earlier than the toads there was a period during which interspecific spawning between female toads and male frogs took place. This appears to have resulted from reduced male toad activity caused by the cold breeding season given that spatial, temporal and behavioural species separation did not occur.     

Moving south: effects of water temperatures on the larval development of invasive cane toads (Rhinella marina) in cool‐temperate Australia

The distributional limits of many ectothermic species are set by thermal tolerances of early‐developmental stages in the life history; embryos and larvae often are less able to buffer environmental variation than are conspecific adults. In pond‐breeding amphibians, for example, cold water may constrain viability of eggs and larvae, even if adults can find suitable thermal conditions in terrestrial niches. Invasive species provide robust model systems for exploring these questions, because we can quantify thermal challenges at the expanding range edge (from field surveys) and larval responses to thermal conditions (in the laboratory). Our studies on invasive cane toads (Rhinella marina) at the southern (cool‐climate) edge of their expanding range in Australia show that available ponds often average around 20°C during the breeding period, 10°C lower than in many areas of the toads’ native range, or in the Australian tropics. Our laboratory experiments showed that cane toad eggs and larvae cannot develop successfully at 16°C, but hatching success and larval survival rates were higher at 20°C than in warmer conditions. Lower temperatures slowed growth rates, increasing the duration of tadpole life, but also increased metamorph body mass. Water temperature also influenced metamorph body shape (high temperatures reduced relative limb length, head width, and body mass) and locomotor performance (increased speed from intermediate temperatures, longer hops from high temperatures). In combination with previous studies, our data suggest that lower water temperatures may enhance rather than reduce recruitment of cane toads, at least in areas where pond temperatures reach or exceed 20°C. That condition is fulfilled over a wide area of southern Australia, suggesting that the continuing expansion of this invasive species is unlikely to be curtailed by the impacts of relatively low water temperatures on the viability of early life‐history stages.     

Diet and foraging effort of Adélie penguins in relation to pack-ice conditions in the southern Ross Sea

We investigated the diet and aspects of foraging effort among Adélie penguins (Pygoscelis adeliae) breeding at three colonies on Ross Island, in the southwestern Ross Sea – Capes Royds, Bird and Crozier – during the chick-provisioning period of three austral summers, 1994–1995, 1995–1996 and 1996–1997. During the study period, pack-ice cover differed in waters offshore of these colonies, by colony, seasons and year. Diet differed among colonies only slightly. The fish Pleuragramma antarcticum was the most important prey, especially during years or periods within years when little pack ice was present. With respect to krill, which composed the remainder of diet, juvenile Euphausia crystallorophias were consumed predominantly in a year of heavy pack-ice cover; more adult krill were consumed in 2 years when pack ice was sparse. Foraging trip duration differed by colony, season and year and was related directly to distance from the colony to the nearest pack ice. The amount of food brought to chicks increased as trip duration increased, to a point (2 days), but then decreased as duration increased further (up to 4 days). On the basis of data on mass of parents and of meal sizes to chicks, it appeared that on the longest trips more of the food gathered by parents was used for self maintenance; on the longest trips, parents lost body mass. Successful foraging during chick rearing, the period when adult foraging is most intense, appears to depend on the proximity of pack ice to nesting colonies for this penguin species. Received: 1 October 1997 / Accepted: 25 April 1998     

Weather conditions and visits to the medical wing of emergency rooms in a metropolitan area during the warm season in Israel: a predictive model

Global climate changes affect health and present new challenges to healthcare systems. The aim of the present study was to analyze the pattern of visits to the medical wing of emergency rooms (ERs) in public hospitals during warm seasons, and to develop a predictive model that will forecast the number of visits to ERs 2 days ahead. Data on daily visits to the ERs of the four largest medical centers in the Tel-Aviv metropolitan area during the warm months of the year (April–October, 2001–2004), the corresponding daily meteorological data, daily electrical power consumption (a surrogate marker for air-conditioning), air-pollution parameters, and calendar information were obtained and used in the analyses. The predictive model employed a time series analysis with transitional Poisson regression. The concise multivariable model was highly accurate (r ² = 0.819). The contribution of mean daily temperature was small but significant: an increase of 1°C in ambient temperature was associated with a 1.47% increase in the number of ER visits (P < 0.001). An increase in electrical power consumption significantly attenuated the effect of weather conditions on ER visits by 4% per 1,000 MWh (P < 0.001). Higher daily mean SO₂ concentrations were associated with a greater number of ER visits (1% per 1 ppb increment; P = 0.017). Calendar data were the main predictors of ER visits (r ² = 0.794). The predictive model was highly accurate in forecasting the number of visits to ERs 2 days ahead. The marginal effect of temperature on the number of ER visits can be attributed to behavioral adaptations, including the use of air-conditioning.     

Delayed recovery of β-glucuronidase activity driven by an Arabidopsis heat shock promoter in heat-stressed transgenic Nicotiana plumbaginifolia

 The expression of the Arabidopsis heat shock protein (HSP) 18.2 promoter-β-d-glucuronidase (GUS) chimera gene was investigated in transgenic Nicotiana plumbaginifolia plants during the recovery phase at normal temperatures (20–22  °C) after a heat shock (HS) treatment. GUS activity increased during the recovery phase after HS at 42  °C for 2 h, and maximal GUS activity was observed after 12 h at normal temperatures, at levels 50–100 times higher than the activity immediately after HS. After HS at 44  °C, little GUS activity was observed during the first 20–24 h at normal temperatures, but the activity increased gradually thereafter, to reach a maximum at 40–50 h. After HS at 45  °C, no GUS activity was observed throughout the experimental period. RT-PCR analysis showed that GUS mRNA remained for 10 h after a 2-h HS at 42  °C and for 40 h after a 2-h HS at 44  °C. These findings demonstrate that brief HS treatment, especially at a sublethal temperature, induces a long-term accumulation of HSP-GUS mRNA during the recovery phase. Received: 31 July 1998 / Revision received: 4 November 1998 / Accepted: 19 February 1999     

Recurrent production of plants of black plum, Syzygium cuminii (L.) Skeels, a myrtaceous fruit tree, from in vitro cultured seedling explants

 The epicotyl segments bearing scaly leave(s), excised from in vitro grown seedlings of Syzygium cuminii, produced multiple shoots when cultivated on Murashige and Skoog's (MS, 1962) medium supplemented with different concentrations of BA (0–2 mg l^–1). The optimum response was recorded on the medium containing 1 mg l^–1 BA. An average of 8.6 shoots per explant were produced 60 days after inoculation, following transfer to fresh medium after 30 days. The shoots were excised, and the residual explants were transferred to fresh medium, where they again developed shoots. Up to five such passages resulted in the production of shoots from the repeatedly subcultured original explants. However, during the fifth passage, organogenic response was negligible and the explants turned brown thereafter. Following repeated harvesting of shoots and subculture of the residual explants, an average of 29 shoots per explant was obtained. The in vitro developed shoots produced roots when transferred to Knop's medium supplemented with 2% sucrose and 1 mg l^–1 IAA. The developed plantlets were planted in soil and transferred to fields after an acclimatization period of 7–8 months. These plants have been thriving well for more than 3 years. The nodal explants excised from in vitro developed shoots and plants also exhibited a similar response when cultured on MS+1 mg l^–1 BA. Thus, a protocol has been developed to raise plants of S. cuminii at any time of the year. Received: 1 December 1998 / Revision received: 1 July 1999 · Accepted: 12 July 1999     

The relationship between body length, age and sexual maturity in the common toad, Bufo bufo

An investigation of the relationship between the onset of sexual maturity, age and body size in common toads Bufo bufo was started in 1984 at a pond in southern England. During the toad breeding seasons of 1984 and 1985, 7259 common toad'metamorphs'were captured and permanently marked so that if captured as adults their true age would be known. Although a very small proportion of males and females reached sexual maturity at ages of two and four years respectively, most did so much later and asynchronously. The body size of toads breeding for the first time was relatively constant for each sex and not correlated with age. The rational behind our understanding of the mechanism of female choice is discussed in the light of these results.     

Lung-based hearing in an “earless” anuran amphibian

The mechanisms of hearing in the fire-bellied toad Bombina orientalis, an “earless” species of amphibian that lacks a standard tympanic middle ear, were studied using laser Doppler vibrometric and neurophysiological techniques. Laser vibrometry demonstrated that the anterolateral body wall overlying the lung is much more responsive to sound than the lateral head surface overlying the inner ear. Covering the lateral body wall with silicone grease dramatically decreased auditory midbrain sensitivity at all frequencies examined, elevating thresholds by 20–25 dB. Filling the lungs with oxygenated saline produced similar decrements in hearing sensitivity, and both manipulations strongly suggest that the lung is the primary route of sound reception in this species. The precise route of transfer of sound energy from the body wall and lungs to the inner ear remains unclear. The lung-based hearing system of “earless” fire-bellied toads may represent the retention of the first auditory mechanism used by early tetrapod vertebrates for detection of airborne sound. Accepted: 10 December 1998