The influence of pasture distribution and temperature on habitat selection by feral pigs in a semi-arid environment

1998 ◽  
Vol 25 (5) ◽  
pp. 547 ◽  
Author(s):  
Nick Dexter
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Radio Telemetry ◽  
Arid Environment ◽  
Food Distribution ◽  
Maximum Temperature ◽  
Feral Pigs ◽  
North West ◽  
Hot Weather ◽  
Two Parameters

The two parameters believed to influence habitat utilisation by feral pigs and wild boar (Sus scrofa) are protection from high temperatures and distribution of food. However, whether there is an interaction between these parameters is unknown. To examine the influence of high temperature on habitat utilisation, the use of four rangeland habitats (shrubland, woodland, riverine woodland, and ephemeral swamps) by feral pigs in north-west New South Wales, Australia, was measured by radio-telemetry during and after a drought. In each habitat, protection from high temperature was indexed once by vegetation cover, at three strata, while over the course of the study, food distribution was indexed by estimating pasture biomass in each habitat. Riverine woodland provided the most shelter from high temperature, followed by woodland, shrubland and ephemeral swamps. On average, ephemeral swamps had the highest pasture biomass, followed by riverine woodland, shrubland and woodland. The amount of pasture in each habitat increased after the drought but changed at different rates. During autumn, spring and summer feral pigs preferred riverine woodland but in winter shrubland was preferred. Multivariate regression indicated that habitat utilisation was significantly influenced by pasture biomass in shrubland and mean maximum temperature in the study area. The results suggest that feral pigs are restricted by high temperatures to more shady habitats during hot weather but when the constraint of high temperature is relaxed they distribute themselves more according to the availability of food.

The influence of pasture distribution, temperature and sex on home-range size of feral pigs in a semi-arid environment

1999 ◽  
Vol 26 (6) ◽  
pp. 755 ◽  
Author(s):  
Nick Dexter
Keyword(s):  
Home Range ◽  
Radio Telemetry ◽  
Arid Environment ◽  
Home Range Size ◽  
Range Size ◽  
Maximum Temperature ◽  
Home Ranges ◽  
Feral Pigs ◽  
South Wales ◽  
Semi Arid

In this study the home-range sizes of feral pigs (Sus scrofa) at Nocoleche Nature Reserve, semi-arid New South Wales were measured by radio-telemetry over the course of a drought. The abundance of food was indexed simultaneously by the amount of pasture in the four most common habitats at Nocoleche (shrubland, woodland, riverine woodland, and ephemeral swamps). The influence of the pig's sex, and mean maximum temperature and pasture biomass on the home-range size of pigs were examined using ANOVA and multiple regression, respectively. Mean home-range size of males was 7.9–11.6 km2 and that for females was 4.2–8.0 km2 . Males had significantly larger home ranges than females, and their home-range size did not change significantly over the course of the drought. In contrast, the size of the home ranges of females changed significantly and was correlated negatively with the abundance of pasture biomass in shrublands and mean maximum temperature, and positively with the abundance of pasture biomass in ephemeral swamps. The conclusion from this study is that males maintained a large, unvarying, home range to maximise access to females while females changed their home-range size according the abundance of food and the constraints of high temperature.

scholarly journals Temperature Trend Analysis and Extreme High Temperature Prediction Based on Weighted Markov Model in Lanzhou

2021 ◽  
Author(s):  
Zhiqiang Pang ◽  
Zhaoxu Wang
Keyword(s):  
High Temperature ◽  
Markov Model ◽  
Prediction Model ◽  
Trend Analysis ◽  
High Temperatures ◽  
Minimum Temperature ◽  
Maximum Temperature ◽  
Temperature Prediction ◽  
Real Situation ◽  
Change Trend

Abstract In this study, temporIn this study, temporal trend analysis was conducted on the annual and quarterly meteorological variables of Lanzhou from 1951 to 2016, and a weighted Markov model for extremely high-temperature prediction was constructed. Several non-parametric methods were used to analyze the time trend. Considering that sequence autocorrelation may affect the accuracy of the trend test, we performed an autocorrelation test and carried out trend analysis for sequences with autocorrelation after removing correlation. The results show that the maximum temperature, minimum temperature, and average temperature in Lanzhou have a significant rising trend and show different performances in each season. In detail, the maximum temperature in summer does not have a significant change trend, while the minimum temperature in winter is the most significant rising trend, which leads to more and more ”warm winter” phenomenon. Finally, we construct a weighted Markov prediction model for extremely high temperatures and obtain the conclusion that the prediction results by the model are consistent with the real situation. and show different performances in each season. In detail, the maximum temperature in summer does not have a significant change trend, while the minimum temperature in winter is the most significant rising trend, which leads to more and more ”warm winter” phenomenon. Finally, we construct a weighted Markov prediction model for extremely high temperatures and obtain the conclusion that the prediction results by the model are consistent with the real situation.

Temperature variation in nest boxes in eastern Australia

2015 ◽  
Vol 37 (2) ◽  
pp. 225 ◽  
Author(s):  
Ross L. Goldingay
Keyword(s):  
Temperature Variation ◽  
Construction Material ◽  
Maximum Temperature ◽  
Extreme Temperatures ◽  
Nest Box ◽  
North West ◽  
Nest Boxes ◽  
Eastern Australia ◽  
Significant Difference ◽  
Hot Weather

Nest boxes are frequently installed in Australia to provide shelter sites for arboreal mammals. Little is known about the temperatures that may be experienced inside nest boxes or the factors that may influence those temperatures. I established paired nest boxes on the south-east and north-west sides of trees at two locations in south-east Queensland to investigate the influence of nest box aspect on nest box temperature. Squirrel gliders (Petaurus norfolcensis) occupied boxes at both locations. I recorded temperatures over a 1-month period in two summers. Temperature varied by up to 20°C within a 24-h period and some nest boxes experienced temperatures above 40°C. There was no significant difference in maximum temperature with nest box aspect but south-east boxes could be 1°C cooler during hot weather. Nest box construction material, colour (brown or green) and volume (0.008 m3 or 0.025 m3) had variable influences on temperature. Nest box installations for non-flying mammals should place nest boxes to minimise extreme temperatures. Further studies are required to determine whether temperature limits the effectiveness of nest boxes at some locations.

scholarly journals Growth Performance and Concentrations of Thyroid Hormones and Growth Hormone in Plasma of Broilers at High Temperatures

1987 ◽  
Vol 40 (4) ◽  
pp. 443 ◽  
Author(s):  
A P Sinurat ◽  
D Balnave ◽  
GH McDowell
Keyword(s):  
Growth Hormone ◽  
High Temperature ◽  
Plasma Concentration ◽  
High Temperatures ◽  
Broiler Chickens ◽  
High Ambient Temperature ◽  
Molar Ratio ◽  
Maximum Temperature ◽  
Food Conversion ◽  
Plasma Growth Hormone

Responses of broiler chickens to a high ambient temperature (35�C) were measured in two experiments. In one experiment temperatures were increased abruptly from 21�C to a daily range of 21-35�C whereas, in the other, temperatures were increased more gradually over 6 days. The high temperatures were maintained for 5 h/day. In' both experiments, birds exposed to the high temperatures ate less food and gained less liveweight than birds maintained at 21�C. Efficiency of food conversion to liveweight gain and body composition were not affected by high temperature but there was a tendency for thyroid weight to decrease. Overall, the plasma concentration of triiodothyronine (T 3) decreased and the plasma concentration of thyroxine (T4) increased, resulting in a decreased T/T4 molar ratio, during exposure to high temperature. The concentration of plasma growth hormone, but not plasma reverse T 3' was increased by high temperature. The initial responses to increased temperature were variable, with birds exposed more gradually adjusting relatively well until the maximum temperature was increased to 35�C. All heated birds readjusted quickly to the daily reduction in temperature to 21�C.

High-temperature survival is limited by food availability in first-instar locust nymphs

2010 ◽  
Vol 58 (5) ◽  
pp. 323 ◽  
Author(s):  
James D. Woodman
Keyword(s):  
High Temperature ◽  
Food Availability ◽  
High Temperatures ◽  
Water Loss ◽  
Local Population ◽  
Maximum Temperature ◽  
Upper Limit ◽  
First Instar ◽  
Low Humidity ◽  
Very High

The Australian plague locust, Chortoicetes terminifera (Walker), is often exposed to high temperature and low humidity in semiarid and arid environments. Early-instar survival under these conditions is an important prerequisite for the formation of high-density aggregations in summer and autumn generations. The present study investigates how first-instar C. terminifera respond to high temperature and low humidity using measures of total body water content, physiological and behavioural transitions during temperature increase, critical upper limit, and mortality relative to food availability. The critical upper limit for fed nymphs was very high at 53.3 ± 1.0°C, with death preceded by a clear progression of changes in behaviour, gas exchange, water loss and excretion. At more ecologically relevant high temperatures, food availability allowed nymphs to behaviourally respond to increased water loss, and the resulting physiological maintenance of water reserves provided cross-tolerance to heat relative to exposure duration and maximum temperature as well as the rate of warming. While very high mortality was recorded at ≥45°C in 6-h direct-exposure experiments, a highly exposed and very poorly vegetated summer environment would be required for local population failures from current high temperatures and low humidity alone.

Response of wheat cultivars to dates of sowing under dryland conditions

1983 ◽  
Vol 101 (3) ◽  
pp. 727-733 ◽  
Author(s):  
R. De ◽  
G. Saran ◽  
B. B. Turkhede ◽  
R. B. Lal ◽  
R. K. Singh ◽  
...  
Keyword(s):  
High Temperatures ◽  
Spring Wheat ◽  
Vegetative Growth ◽  
Field Experiments ◽  
Arid Environment ◽  
Seedling Stage ◽  
Wheat Cultivars ◽  
North West ◽  
Early Differentiation ◽  
Semi Arid

SUMMARYField experiments made for 4 years between 1976–7 and 1979–80 in a semi-arid environment of north-west India showed that the productivity of dryland unirrigated wheat can be increased considerably by adjusting the date of sowing to conducive atmospheric temperatures. Sowing in the middle of November when daily mean temperatures ranged between 19 and 21 °C produced yields ranging between 2·6and 3·5t/ha (averaged over the 4 years) compared with 1·4–3·3 t/ha obtained from the crop sown by mid-October when the daily mean temperature ranged between 24 and 26 °C. The tall cultivar C 306, a derivative of winter x spring wheat cross, could withstand sowing at higher temperatures (mid-October) more than the spring wheats. High temperatures prevailing during the seedling stage of spring wheats shortened their vegetative growth and initiated early differentiation. Night temperatures above 13 °C coupled with day temperatures of 33–35 °C in the last fortnight of October adversely affected the tillering of spring wheats sown on 15 October and produced smaller spikes with few fertile spikelets.

Effect of High Temperatures on Microstructure of Repair Mortars Containing Artificial Aggregate Based on Sintered Ash

2015 ◽  
Vol 1100 ◽  
pp. 147-151
Author(s):  
Jiří Bydžovský ◽  
Tomáš Melichar ◽  
Ámos Dufka ◽  
Michaela Fiedlerová
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Analytical Methods ◽  
Maximum Temperature ◽  
Cement Matrix ◽  
Lightweight Aggregates ◽  
Temperature Influence ◽  
Repair Materials ◽  
Repair Mortars

The research presented in this article is focused on analyzing of high temperature influence on behaviour and microstructure of polymeric-cement matrix based repair materials containing lightweight aggregates on the basis of sintered ash. Also admixtures and polymeric fibres were applied to obtain the required parameters. The study of microstructure and its changes was realized using SEM, XRD and DTA analytical methods. Maximum temperature of exposure environment of the tested mortars was 1000°C, while cooling of specimens was gradual.

The influence of pasture distribution, and temperature on adult body weight of feral pigs in a semi-arid environment

2003 ◽  
Vol 30 (1) ◽  
pp. 75 ◽  
Author(s):  
Nick Dexter
Keyword(s):  
Body Weight ◽  
Arid Environment ◽  
Maximum Temperature ◽  
Feral Pigs ◽  
South Wales ◽  
Significant Difference ◽  
Adult Body ◽  
Adult Body Weight ◽  
The Mean ◽  
Semi Arid

The influence of high temperature and the distribution and abundance of pasture on variation in adult body weight of feral pigs was examined at Nocoleche Nature Reserve, semi-arid New South Wales, over the course of a drought. The influence of the pig's sex, and the mean maximum environmental temperature and pasture biomass on the adult pig's body weight, were examined. There was no significant difference between the sexes with respect to adult body weight, with the mean adult body weight being 37.5 kg for both sexes. Adult body weight was negatively correlated with mean maximum temperature and positively correlated with pasture biomass in woodlands. The conclusion from this study is that body weight increased over the course of the study as the drought eased but showed definite seasonal increases during winter when temperatures were lowest.

Sexual behaviour and semen characteristics of boars: effects of high temperature

1981 ◽  
Vol 21 (108) ◽  
pp. 39 ◽  
Author(s):  
CG Winfield ◽  
PH Hemsworth ◽  
DB Galloway ◽  
AW Makin
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Sexual Behaviour ◽  
The Other ◽  
Temperature Cycle ◽  
Large White ◽  
Air Temperatures ◽  
Semen Characteristics ◽  
Hot Weather ◽  
Copulatory Behaviour

The effect of 4,7 or 10-day periods of high air temperatures on the sexual behaviour and semen characteristics of mature Large White crossbred boars was determined in three experiments. In experiment 1, boars kept at 40�C for 8 hours and 30�C for 16 hours each day for 7 days had lower courting behaviour activity when tested at 40�C than control boars tested at <25�C. After similar heat treatment in experiment 2, boars tested at 30�C showed no significant differences in courting or copulatory behaviour from control boars, but the semen of two of six treated boars showed evidence of severe testicular- epididymal dysfunction. The semen of a third treated boar showed evidence of moderate testicular-epididymal dysfunction. In experiment 3, four boars were given a similar daily high temperature cycle to the above, either for 4 or 10 days. Two of the four boars given high temperatures for 10 days had semen with signs of severe testicular-epididymal dysfunction. The semen of the other two boars in this group, and one boar treated for 4 days, showed evidence of moderate dysfunction. It was concluded that during hot weather boars will mate normally during the cooler part of the day, and that they are able to tolerate short periods of heat stress (< 4 days) without detriment to semen characteristics. Protection from longer periods of high temperatures ( > 7 days) is necessary.

High Temperature n- and p-type Doped Microcrystalline Silicon Layers Grown by VHF PECVD Layer-by-Layer Deposition

2003 ◽  
Vol 762 ◽  
Author(s):  
A. Gordijn ◽  
J.K. Rath ◽  
R.E.I. Schropp
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
High Temperatures ◽  
Continuous Wave ◽  
Hydrogen Plasma ◽  
Silicon Layer ◽  
Dark Conductivity ◽  
High Deposition Rate ◽  
Layer By Layer ◽  
Microcrystalline Silicon

AbstractDue to the high temperatures used for high deposition rate microcrystalline (μc-Si:H) and polycrystalline silicon, there is a need for compact and temperature-stable doped layers. In this study we report on films grown by the layer-by-layer method (LbL) using VHF PECVD. Growth of an amorphous silicon layer is alternated by a hydrogen plasma treatment. In LbL, the surface reactions are separated time-wise from the nucleation in the bulk. We observed that it is possible to incorporate dopant atoms in the layer, without disturbing the nucleation. Even at high substrate temperatures (up to 400°C) doped layers can be made microcrystalline. At these temperatures, in the continuous wave case, crystallinity is hindered, which is generally attributed to the out-diffusion of hydrogen from the surface and the presence of impurities (dopants).We observe that the parameter window for the treatment time for p-layers is smaller compared to n-layers. Moreover we observe that for high temperatures, the nucleation of p-layers is more adversely affected than for n-layers. Thin, doped layers have been structurally, optically and electrically characterized. The best n-layer made at 400°C, with a thickness of only 31 nm, had an activation energy of 0.056 eV and a dark conductivity of 2.7 S/cm, while the best p-layer made at 350°C, with a thickness of 29 nm, had an activation energy of 0.11 V and a dark conductivity of 0.1 S/cm. The suitability of these high temperature n-layers has been demonstrated in an n-i-p microcrystalline silicon solar cell with an unoptimized μc-Si:H i-layer deposited at 250°C and without buffer. The Voc of the cell is 0.48 V and the fill factor is 70 %.

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