Miniature Temperature Data Loggers Research Articles

Miniature temperature data loggers increase precision and reduce bias when estimating the daily survival rate for bird nests

Miniature temperature data loggers increase precision and reduce bias when estimating the daily survival rate for bird nests

Ground thermal and geomechanical conditions in a permafrost-affected high-latitude rock avalanche site (Polvartinden, northern Norway)

Abstract. On 26 June 2008, a rock avalanche detached in the northeast facing slope of Polvartinden, a high-alpine mountain in Signaldalen, northern Norway. Here, we report on the observed and modelled past and present near-surface temperature regime close to the failure zone, as well as on a subsequent simulation of the subsurface temperature regime, and on initial geomechanical mapping based on laser scanning. The volume of the rock avalanche was estimated to be approximately 500 000 m3. The depth to the actual failure surface was found to range from 40 m at the back of the failure zone to 0 m at its toe. Visible in situ ice was observed in the failure zone just after the rock avalanche. Between September 2009 and August 2013, ground surface temperatures were measured with miniature temperature data loggers at 14 different localities, close to the original failure zone along the northern ridge of Polvartinden and on the valley floor. The results from these measurements and from a basic three-dimensional heat conduction model suggest that the lower altitudinal limit of permafrost at present is at 600–650 m a.s.l., which corresponds to the upper limit of the failure zone. A coupling of our in situ data with regional climate data since 1958 suggests a general gradual warming and that the period with highest mean near surface temperatures on record ended four months before the Signaldalen rock avalanche detached. A comparison with a transient permafrost model run at 10 m depth, representative for areas where snow accumulates, strengthen these findings, which are also in congruence with measurements in nearby permafrost boreholes. It is likely that permafrost in and near the failure zone is presently subject to degradation. This degradation, in combination with the extreme warm year antecedent to the rock failure, is seen to have played an important role in the detaching of the Signaldalen rock avalanche.

Geographic variation in cone volatiles and pollinators in the thermogenic African cycad Encephalartos ghellinckii Lem.

Heat and odour production can have profound effects on pollination in cycads. It is therefore expected that these traits would co-vary geographically with pollinator assemblages. Such intraspecific variation, may lead to the evolution of pollination ecotypes, which can be an early stage of pollinator-mediated speciation. We measured cone temperatures using miniature temperature data loggers and examined the composition of cone volatile odours using headspace sampling and analysis with gas chromatography-mass spectrometry in four populations spanning the range of the African cycad Encephalartos ghellinckii. Pollinator assemblages were also investigated in three populations. Male and female cones were thermogenic at pollen shed and receptive stages, respectively, but patterns of thermogenesis did not vary among populations. Scent emissions from cones in populations in the Drakensberg Mountains were characterised by cis-β-ocimene, β-myrcene and (3E)-1,3-octadiene, while camphene and α-pinene were characteristic of scent emissions from cones in populations closer to the coast. These differences in volatile blends corresponded with differences in insect assemblages. These results confirm intraspecific variation in volatile emissions of E.ghellinckii and support the predictions that intraspecific variation in volatile emissions will be associated with shifts in pollinator assemblages. While further work needs to be done to test for local adaptation in this system, this preliminary evidence is consistent with the formation of pollination ecotypes in the E.ghellinckii species complex.

Overwintering of Gopher Tortoises (Gopherus polyphemus) Translocated to the Northern Limit of Their Geographic Range: Temperatures, Timing, and Survival

Abstract We examined overwintering behavior in gopher tortoises (Gopherus polyphemus) translocated to the northern periphery of their geographic range by using miniature temperature data loggers during 2 winters. All adult and juvenile tortoises monitored with temperature loggers survived overwintering; however, during the course of the study 2 translocated juvenile tortoises without temperature loggers died during winter months. Onset and termination of overwintering were not different between the 2 yrs and were not correlated with mean above-ground air temperature. Mean overwinter duration was 127 ± 9 d SD and 128 ± 13 d SD during 2002–2003 and 2004–2005, respectively. Tortoises experienced temperatures as low as 7°C and as high as 31°C while overwintering; however, most (12 of 15) tortoises experienced very little (< 1°C) mean daily temperature fluctuation despite air temperatures regularly dropping below 0°C and exceeding 20°C. The overall mean temperature of overwintering tortoises was 12.4° ± 0.8°C ...

Nonclinical vaccine safety evaluation: advantages of continuous temperature monitoring using abdominally implanted data loggers

Fever has been reported as the most common adverse event after vaccination in infants and children. For this reason it is important that, prior to clinical testing of a new vaccine, change in body temperature following vaccination is tested carefully in nonclinical animal studies. Since both the timing and the height of the temperature peak after vaccination may differ from vaccine to vaccine, it is important that the time point for body temperature measurement should be chosen on a case-by-case basis with sufficient knowledge of the specific vaccine. In order to determine the best time point for rectal body temperature measurement after vaccination with a new vaccine candidate against N. meningitidis serogroup B, to be applied in a formal Good Laboratory Practice (GLP) toxicology study, miniature temperature data loggers were implanted into the peritoneal cavity of rabbits. The continuous body temperature monitoring appeared to give a complete picture of the entire body temperature kinetics after vaccination. The body temperature peaked at 4 h after vaccination, and this time point was subsequently applied in the toxicology study. Measured body temperature values at the selected time point of 4 h after vaccination were comparable in the continuous temperature setting and in the formal toxicology study, i.e. rectal temperature measurement at one time point. In the present study implanted temperature loggers were successfully used to define an adequate time point to be applied in determining rectal body temperature in a formal GLP toxicology study with a new vaccine candidate.

気温・地温観測結果からみた飛騨山脈槍・穂高連峰における山岳永久凍土の分布状況

飛騨山脈南部槍・穂高連峰における山岳永久凍土の有無およびその分布状況を明らかにするため，小型自記温度計を用いて，気温および地温の観測をおこなった．気温観測の結果，槍・穂高連峰主稜線上は不連続永久凍土帯の気温条件下にあることが判明した．また，地表面温度観測の結果，本山域のカール内に存在する岩石氷河や崖錐斜面上の多数の地点における晩冬季の積雪底地表面温度（BTS）の値は，それらの地点に永久凍土が存在する可能性があることを示した．特に，大キレットカール内の岩石氷河上では，永久凍土が存在している可能性が高いことを示すBTSや年平均地表面温度などの値が複数年にわたって得られた．地表面が特に粗大な礫から成る地点では，冬季の地表面温度の低下が他地点よりも顕著であった．これは，冬季に粗大礫の上部が積雪面上に露出し，その露出部が寒冷な外気により冷却され，礫自体の冷却が進行していくことによりもたらされたものと考えられる．

NORPERM, the Norwegian Permafrost Database – a TSP NORWAY IPY legacy

Abstract. NORPERM, the Norwegian Permafrost Database, was developed at the Geological Survey of Norway during the International Polar Year (IPY) 2007-2009 as the main data legacy of the IPY research project Permafrost Observatory Project: A Contribution to the Thermal State of Permafrost in Norway and Svalbard (TSP NORWAY). Its structural and technical design is described in this paper along with the ground temperature data infrastructure in Norway and Svalbard, focussing on the TSP NORWAY permafrost observatory installations in the North Scandinavian Permafrost Observatory and Nordenskiöld Land Permafrost Observatory, being the primary data providers of NORPERM. Further developments of the database, possibly towards a regional database for the Nordic area, are also discussed. The purpose of NORPERM is to store ground temperature data safely and in a standard format for use in future research. The IPY data policy of open, free, full and timely release of IPY data is followed, and the borehole metadata description follows the Global Terrestrial Network for Permafrost (GTN-P) standard. NORPERM is purely a temperature database, and the data is stored in a relation database management system and made publically available online through a map-based graphical user interface. The datasets include temperature time series from various depths in boreholes and from the air, snow cover, ground-surface or upper ground layer recorded by miniature temperature data-loggers, and temperature profiles with depth in boreholes obtained by occasional manual logging. All the temperature data from the TSP NORWAY research project is included in the database, totalling 32 temperature time series from boreholes, 98 time series of micrometeorological temperature conditions, and 6 temperature depth profiles obtained by manual logging in boreholes. The database content will gradually increase as data from previous and future projects are added. Links to near real-time permafrost temperatures, obtained by GSM data transfer, is also provided through the user interface.

Scent chemistry and patterns of thermogenesis in male and female cones of the African cycad Encephalartos natalensis (Zamiaceae)

Most, if not all, extant cycads are pollinated by insects which use the cones as larval brood sites. These interactions appear to be mediated by cone volatiles, and, in some species, by patterns of thermogenesis. We investigated the chemical composition of volatile emissions and patterns of thermogenesis in cones of the South African cycad Encephalartos natalensis, using a gas chromatograph–mass spectrometer (GC–MS) and miniature temperature data loggers (ibuttons), respectively. This was done during various developmental stages (before and during receptivity and pollen release) for both female and male cones. A total of 31 compounds were identified in headspace samples; 17 of which were common to both sexes, 12 found only in male cones, and two found only in female cones. The major volatiles in pollen and female cones are (3 E)-1,3-octadiene (averaging 54.25% and 15.82% of total emissions), (3 E,5 Z)-1,3,5-octatriene (averaging 13.37% and 47.66%), and α-pinene (averaging 16.29% and 12.24%). Female cones were not thermogenic before and during receptivity whereas pollen cones were thermogenic during pollen shedding. Thermogenesis of male cones occurred between 1400 h and 1530 h on successive afternoons, reaching an average of c. 10.5 °C above ambient temperature. Volatile emissions and thermogenesis occurred in association with insect activity on the cones suggesting that they both play a role in regulating insect behaviour.

Responses of simultaneously recorded intraperitoneal and subcutaneous temperatures of Black Bedouin goats to transient thyrosuppression during cold stress

Unlike poikilotherms, homeotherms resist wide amplitudes of core body temperature (Tcore) fluctuation when exposed to reasonably variant ambient temperature (Ta) extremes. The degree of cold/heat thermotolerance varies tremendously amongst mammalian species. Thermotolerance can be partially inferred by the extent of resistance in body temperature displacement from normothermia when subjected to thermal stress. Regulation of thyroid calorigenic hormones is primarily contingent upon thermal homeostasis. Thyrosuppression generally exacerbates cold stress and hence may be a useful tool to examine the extent of cold-tolerance. An experiment was conducted to examine the extent of cold-tolerance on artificially goitrous Black Bedouin goats. Ten goat kids (initial Avg. BW = 30.6 ± 0.4 kg) were fitted with two miniature temperature data loggers, intraperitoneally and subcutaneously to identify core (Tcore) and subcutaneous (Tsq) temperature responses, respectively, to chronically (47 days) cold (< 10 °C) environment along with or without oral administration of the thyreostat propylthiouracil (PTU 20 mg/kg BW/day). Five animals served as controls (CON) whereas the remaining five were treated with PTU for 31 out of the overall 47-day observation period. Despite its 74.5%-evoked transient depression of circulating free thyroxine (FT4), PTU-treatment failed (P > 0.10) to cause significant displacements in Tcore or Tsq as compared to CON values throughout the 52-day trial period. As a function of Ta, Tcore − Tsq thermal gradient revealed a significantly (P < 0.01) linear regression (r2 = 0.41), to indirectly infer a graded blood redistribution from peripheral to splanchnic vascular beds with the fall in Ta. In the light of the current findings, it can be deduced that– in addition to the fact that it is superior in terms of heat-tolerance– the Black Bedouin goat is also profoundly cold-tolerant. Furthermore, our recently developed technique in concurrently recording Tcore and Tsq proves efficient and feasible to simultaneously record temperatures of different body sites in free-roaming animals, thereby overcoming potentially erroneous artifacts caused by frequent experimenter intrusion.

Responses of core and peripheral temperatures to chronic cold stress in transiently goitrous goats

Thyroid hormones play a major role in controlling basal metabolic rate, body temperature and hemodynamics. Responses of core and peripheral body temperatures to transient use of thyreostatic drugs are seldom measured simultaneously under chronic experimental settings. We developed a technique to attain this goal. Eighteen Damascus goat kids (initial Avg. BW=44±0.7 kg) underwent a minor invasive surgical procedure to implant two miniature temperature data loggers, intraperitoneally and subcutaneously, to assess core ( T core) and subcutaneous ( T sq) temperature changes when subjected to chronic (47 days) cold (< 10 °C) environment along with or without oral administration of the reversible goitrogen 6-N-propyl-2-thiouracil (PTU; 20 mg/kg BW/day). Nine animals served as controls whereas the remaining nine were treated with PTU for 31 out of total 47-day trial period. The PTU treatment significantly ( P<0.05) depressed circulating free thyroxine (FT4), followed by a rebound after termination. Prior to initiation of PTU treatment, all animals displayed similar daily means of T core and T sq. Subsequently, both temperatures precipitously declined ( P<0.01) with the gradual drop in ambient temperature ( T a) overtime. However, PTU caused an immediate and further drop in T sq, suggesting a reduction in cutaneous perfusion. Interestingly, on the other hand, a delayed downregulation of T core by PTU occurred 14 days post-treatment, indicating a relatively slower depression in metabolic thermogenesis after suppression of circulating thyroxine. Upon termination of PTU, T core but not T sq, returned to simulate control levels. Results from the current study show the practicality of our technique to concurrently record core and peripheral temperatures in chronically-instrumented animals, and that PTU causes a marked depression in thermoregulatory ability during cold stress with no indication for a reduction in the temperature set-point.

EFFECTS OF SURGICAL IMPLANTATION OF TEMPERATURE DATALOGGERS ON REPRODUCTION OF CAPTIVE STRIPED SKUNKS (MEPHITIS MEPHITIS)

A total of 20 (14 females, six males) captive striped skunks (Mephitis mephitis) with miniature temperature dataloggers implanted free in the abdominal cavity were examined for reproductive performance and pathology because of implants. Eleven of 12 female skunks reproduced successfully 45.9+/-3.7 days after surgery to remove implanted dataloggers. The pregnancy rate of 91.7% (11/12) was much higher than other captive studies and was comparable with that of wild skunks. Eight striped skunks (six males, two females) that were euthanatized and necropsied after having implants in the abdominal cavity for 5 mo showed no apparent pathology associated with the implant. Implantation of the intraperitoneal devices did not lead to complications in abdominal tissues. Neither implant nor surgery affected reproduction. We conclude that implanted dataloggers can safely be used in physiologic studies of striped skunks or possibly other small carnivores in captive or field studies.

Mountain permafrost distribution in Dovrefjell and Jotunheimen, southern Norway, based on BTS and DC resistivity tomography data

The influence of climate and topography on the distribution of permafrost within the Dovrefjell and Jotunheimen areas, southern Norway, is analysed. A dataset of 972 BTS (bottom temperature of winter snow) measurements was analysed in relation to altitude, potential direct incoming radiation, aspect, snow depth, curvature and slope. To confirm and characterise permafrost-transition zones indicated from the BTS measurements, miniature temperature data-loggers, borehole temperatures, one-dimensional DC resistivity soundings and two-dimensional DC resistivity tomography were used. In addition, small-scale variance analyses upon the BTS values were performed using spatial-statistical methods. Results confirm that BTS values are highly correlated with altitude. Based on analysis of BTS data, the lower limit of possible permafrost is 1490 m a.s.l. on Dovrefjell and 1460 m a.s.l. in Jotunheimen. The relation between altitude and BTS suggests that the climate conditions on Dovrefjell and in Jotunheimen are similar with respect to permafrost distribution. Potential direct incoming radiation (PR) has a minor influence on BTS. A significant correlation between both surface moisture and surface type conditions in summer and BTS measurements were found. The results from Jotunheimen suggest that 20-45% of the variance in BTS results that are not explained by altitude are explained by small-scale spatial variance within a 20-30 m range. The results from the BTS measurements and the two-dimensional DC resistivity tomography were highly consistent.

Miniature data loggers for remote measurement of body temperature in medium-sized rodents

We have investigated the use of miniature temperature data loggers for the recording of abdominal temperature in laboratory animals, using the guinea pig as a model. The data loggers, which are small (16 cm 3), light (20 g) and have a battery life of ±5 years, recorded both the normal abdominal temperature of guinea pigs, and their febrile response to an intramuscular injection of 50 μg/kg lipopolysaccharide ( E. coli) every 5 min for the duration of the experiment (21 days), to a resolution of at least 0.05°C. No calibration shifts or loss of data occurred during the study period. However, despite their small size and versatility, we found that the loggers were suited for use only in guinea pigs with a body mass of ∼600 g or greater. In smaller animals, the loggers caused peritonitis.

Phenology and ecology of hibernation in spotted turtles (Clemmys guttata) near the northern limit of their range

Using mark-recapture techniques, temperature-sensitive radio transmitters, and miniature temperature data loggers we investigated the hibernation ecology of northern temperate zone spotted turtles (Clemmys guttata) in Georgian Bay, Ontario, over 4 winters (1993-1997). We observed 18 hibernacula that were occupied by 34 turtles; 11 hibernacula were apparently occupied by single turtles, and 7 were used communally by up to 9 individuals. Hibernacula were located in swamps and were of 2 types: sphagnum moss hummock (n = 15) and rock cavern (n = 3). Almost half of the individuals (16 of 34) used the same hibernaculum in at least 2 winters. Turtles entered hibernacula between mid-September and October, when their body temperature was between 12 and 16°C, and exited them in mid to late April, when ambient temperatures ranged between 1 and 5°C. A waterproof temperature data logger attached to a turtle indicated that this turtle was protected from freezing in a thermally stable hibernaculum (body temperature range 0.3-3.9°C) despite highly variable (a 37°C change over 5 days) and low air temperatures (minimum -35°C). Loss of body mass (2%) during hibernation was not significant. We observed no mortality within hibernacula over the 4 winters; however, 3 turtles were destroyed by predators near the hibernacula. These data provide insight into the role of climate in limiting the northern distribution of this species.

Miniature temperature dataloggers for mapping and monitoring of permafrost in high mountain areas: first experience from the Swiss Alps

Measurements of bottom temperatures of the winter snow cover (BTS) constitute a well-established method to map permafrost distribution in mountain areas. A method for continuous measurements of BTS with miniature dataloggers (MTDs) is used with a newly developed logger. This new tool is specially designed for rough field conditions. It was tested in two case studies on and around rock glaciers in Switzerland. One test site was in the Murtel-Corvatsch area (Upper Engadin) and the other in the Furggentalti area (Bernese Alps). The basic assumptions of the conventional BTS method were verified with continuous measurements. Important boundary conditions for BTS measurements are a sufficiently thick, undisturbed snow cover and an adequate measurement time. In autumn, before the snow cover is well developed, air circulation is still possible within the coarse active layer of rock glaciers, and heat exchange through the thin snow cover is facilitated. At the end of winter, meltwater percolation disturbs the equilibrium BTS. At the base of an artificially compacted snow cover, temperatures were influenced by atmospheric variations throughout the whole winter. Use of the new loggers is suggested as suitable for mapping and monitoring the distribution and long-term development of mountain permafrost. Process understanding in the active layer of coarse debris material, on the other hand, needs further investigation. Copyright © 1999 John Wiley & Sons, Ltd. La mesure des temperatures sous la couverture de neige en hiver (BTS) constitue une methode bien etablie pour cartographier la distribution du pergelisol dans les regions de montagne. Des mesures continues de BTS avec des enregistreurs de donnees miniaturises (MTD) ont ete realisees avec une nouvelle boite d'enregistrement. Ce nouvel instrument a ete specialement construit pour travailler dans des conditions de terrain severes. Il a ete teste en deux endroits sur et autour des glaciers rocheux de Suisse. Un site teste etait dans la region de Murtel-Corvatsch (Engadine superieure) et l'autre dans la region de Furggentalti (Alpes bernoises). Les affirmations de base de la methode conventionnelle du BTS ont ete verifiees par des mesures continues. Des conditions importantes pour la realisation de mesures BTS sont l'existence d'une couverture de neige non remaniee suffisamment epaisse et le choix d'un moment adequat pour la mesure. En automne alors que la couverture de neige n'est pas encore bien developpee, une circulation de l'air est encore possible dans la couche active grossiere des glaciers rocheux et les echanges de chaleur au travers de la fine couche de neige est facilitee. A la fin de l'hiver, la percolation d'eaux de fonte perturbe l'equilibre BTS. A la base d'une couche de neige artificiellement compactee, les temperatures ont ete influencees pendant tout l'hiver par les variations atmospheriques. L'emploi de ces nouveaux enregistreurs est probablement approprie pour cartographier et suivre la distribution et l'evolution a long terme du pergelisol de montagne. Comprendre les processus actifs dans une couche active formee de materiaux grossiers necessite cependant des recherches plus poussees. Copyright © 1999 John Wiley & Sons, Ltd.

Hyporheic temperature patterns within riffles

This paper outlines the results of a pilot study using data at 12 min intervals from 20 miniature temperature dataloggers to establish vertical and longitudinal temperature patterns within a river bed. Data are presented from two adjacent riffles immediately below the Blithfield Reservoir on the River Blithe, Staffordshire, UK, for a five day period in July 1994. Hyporheic temperatures were warmer than those of groundwater, colder than those of surface water and decreased with depth into the river bed. At the heads of the riffles shallow sites (20 cm depth) mirrored surface temperature patterns but were on average 1.53°C cooler while deeper sites (40 cm depth) were 2.60°C cooler on average. Hyporheic temperatures lagged behind the surface water pattern and lag times increased with depth. Sites at the riffle tails generally displayed temperature patterns similar to those of the groundwater system: on average, temperatures were 4.32°C cooler than surface water temperatures and showed no significant variation. Hyporheic temperature patterns at the heads of the riffles suggested downwelling surface water, while the tails appeared to be influenced by upwelling groundwater. Both riffles displayed similar hyporheic temperature patterns but riffle 1 was on average 1.22°C warmer per site than riffle 2. Temperature differences between the riffles are attributed to bed form and substratum composition. These factors may have significant ecological implications including rates of organic matter decomposition, invertebrate life cycles and salmonid egg hatching times.