scholarly journals Warming in the land of the midnight sun: breeding birds may suffer greater heat stress at high- vs low-Arctic sites

2021 ◽  
Author(s):  
Ryan Sean O'Connor ◽  
Audrey Le Pogam ◽  
Kevin G Young ◽  
Oliver P Love ◽  
Christopher J Cox ◽  
...  
Keyword(s):  
High Latitude ◽  
Activity Level ◽  
Threshold Temperature ◽  
Temperature Threshold ◽  
Sustained Activity ◽  
Snow Bunting ◽  
Reduce Activity ◽  
Low Arctic ◽  
Negative Impacts ◽  
Operative Temperatures

Rising global temperatures are expected to increase reproductive costs for wildlife as greater thermoregulatory demands interfere with essential breeding activities such as parental care. However, predicting the temperature threshold where reproductive performance is negatively impacted remains a significant hurdle. Using a novel thermoregulatory polygon approach, we predicted the threshold temperature at which an Arctic songbird-the snow bunting (Plectrophenax nivalis)-would need to reduce activity and perform below the 4-times basal metabolic rate (BMR) required to sustain nestling provisioning to avoid overheating. We then compared this threshold to operative temperatures recorded at high (82°N) and low (64°N) Arctic sites to estimate how heat constraints translate into site-specific impacts on sustained activity level. We predict buntings would become behaviourally constrained at operative temperatures above 11.7°C, whereupon they must reduce provisioning rates to maintain thermal balance. Low Arctic sites had larger fluctuations in solar radiation, producing consistent daily periods when operative temperatures exceeded 11.7°C. However, high-latitude birds faced entire, consecutive days where parents would not be able to sustain required provisioning rates. These data indicate that Arctic warming is likely already disrupting the breeding performance of cold-specialist birds, but also suggests counterintuitive and severe negative impacts of warming at high-latitude breeding locations.

scholarly journals Impact of climate and moonlight on a venomous mammal, the Javan slow loris (Nycticebus javanicus Geoffroy, 1812)

2014 ◽  
Vol 83 (4) ◽  
pp. 217-225 ◽  
Author(s):  
Eva Johanna Rode-Margono ◽  
K. Anne-Isola Nekaris
Keyword(s):  
Climatic Factors ◽  
Prey Availability ◽  
Interactive Effect ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Activity Level ◽  
Environmental Data ◽  
Foraging Efficiency ◽  
Slow Loris ◽  
Reduce Activity

Predation pressure, food availability, and activity may be affected by level of moonlight and climatic conditions. While many nocturnal mammals reduce activity at high lunar illumination to avoid predators (lunarphobia), most visually-oriented nocturnal primates and birds increase activity in bright nights (lunarphilia) to improve foraging efficiency. Similarly, weather conditions may influence activity level and foraging ability. We examined the response of Javan slow lorises (Nycticebus javanicus Geoffroy, 1812) to moonlight and temperature. We radio-tracked 12 animals in West Java, Indonesia, over 1.5 years, resulting in over 600 hours direct observations. We collected behavioural and environmental data including lunar illumination, number of human observers, and climatic factors, and 185 camera trap nights on potential predators. Nycticebus javanicus reduced active behaviours in bright nights. Although this might be interpreted as a predator avoidance strategy, animals remained active when more observers were present. We did not find the same effect of lunar illumination on two potential predators. We detected an interactive effect of minimum temperature and moonlight, e.g. in bright nights slow lorises only reduce activity when it is cold. Slow lorises also were more active in higher humidity and when it was cloudy, whereas potential predators were equally active across conditions. As slow lorises are well-adapted to avoid/defend predators by crypsis, mimicry and the possession of venom, we argue that lunarphobia may be due to prey availability. In bright nights that are cold, the combined effects of high luminosity and low temperature favour reduced activity and even torpor. We conclude that Javan slow lorises are lunarphobic – just as the majority of mammals.

scholarly journals A new southern high-latitude index

1998 ◽  
Vol 16 (12) ◽  
pp. 1589-1598 ◽  
Author(s):  
P. Ballatore ◽  
C. G. Maclennan ◽  
M. J. Engebretson ◽  
M. Candidi ◽  
J. Bitterly ◽  
...  
Keyword(s):  
High Latitude ◽  
Activity Level ◽  
Polar Cap ◽  
Geomagnetic Index ◽  
Level Indicator ◽  
Ae Index ◽  
Average Activity ◽  
Using Data ◽  
Auroral Phenomena ◽  
Southern High Latitude

Abstract. We have developed and examined a new regional geomagnetic index AES-80, defined similarly to the classical auroral electrojet AE index, using data from five Antarctic stations located at corrected geomagnetic latitudes about 80 °S. Because only sparse ground-based information can be derived from auroral latitudes in the Southern Hemisphere, and because no index comparable to AE can be constructed from locations in the south, the possibility of using AES-80 as a measure of high latitudes and polar cap activity is investigated. As a global average activity level indicator, it is found that in general AES-80 gives results rather similar to the classical AE index. However AES-80 provides a more robust measure of the occurrence of high-latitude geomagnetic activity.Key words. Magnetospheric physics (auroral phenomena; polar cap phenomena).

scholarly journals The Effect of Alcoholic Extract of Rhizomes of Greater Galangal (Alpinia galanga L.) on the Serum Antioxidant Enzymes for Japanese Quail During Oxidative Stress Induced by Hydrogen Peroxide

2021 ◽  
Vol 34 (1) ◽  
pp. 171-180
Author(s):  
Asrar M. S. Al-Mosawy ◽  
Khalid C. K. Al-Salhie
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Antioxidant Enzymes ◽  
Japanese Quail ◽  
Activity Level ◽  
Alcoholic Extract ◽  
Fourth Group ◽  
Significant Difference ◽  
Males And Females ◽  
Negative Impacts

This study aimed to investigate the effect of alcoholic extract of greater galangal rhizomes on the serum antioxidant enzymes level in Japanese quail during oxidative stress induced by hydrogen peroxide. Two hundred and sixteen, 7 days-old of Japanese quail birds were randomly distributed into four groups (n=54) with three replicates per group and 18 chicks per replicate. The groups as follows: the first group was drank water without any addition as control. The second group was supplied with 4 ml.-1 hydrogen peroxide H2O2 (40%). The third group was supplied with 4 ml.-1 both hydrogen peroxide (40%) and alcoholic extract of greater galangal rhizomes. The fourth group was supplied with 4 ml.-1 alcoholic extract of greater galangal rhizomes. The results showed the lowest significant (P<0.05) decrease of malonaldehyde (MDA), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) concentrations in the fourth group while, the highest significant (P<0.05) increase was recorded in the second group. The highest significant (P<0.05) activity level of superoxide dismutase (SOD) and glutathione peroxidase (GPx) recorded in the fourth group, on the other hand, it was significantly lowest in the second group. The results explained there is no significant difference (P<0.05) in the concentration of MDA,SOD, GPx AST and ALT between the first (control) and third groups. The results indicated  there is no significant differs between males and females in the MDA,SOD, GPx AST and ALT. It can be concluded, oxidative stress was caused a negative impacts on serum SOD, GPx. AST and ALT enzymes. Moreover, it was caused an increase in MDA levels. The alcoholic extract of rhizomes of greater galangal was reduced and reversed the H2O2 impacts. All parameters non-significantly influenced by sexes.

Influence of temperature, photoperiod and humidity on oviposition and egg hatch of the root-feeding flea beetle Longitarsus bethae (Chrysomelidae: Alticinae), a natural enemy of the weed Lantana camara (Verbenaceae)

2007 ◽  
Vol 97 (2) ◽  
pp. 111-116 ◽  
Author(s):  
D.O. Simelane
Keyword(s):  
Relative Humidity ◽  
Biological Control Agent ◽  
Flea Beetle ◽  
Lantana Camara ◽  
Day Length ◽  
Threshold Temperature ◽  
Temperature Threshold ◽  
Continuous Exposure ◽  
Egg Hatch ◽  
Root Feeding

AbstractThe root-feeding flea beetle Longitarsus bethae Savini & Escalona, was introduced into South Africa as a candidate biological control agent for the noxious and invasive weed, Lantana camara L. As part of the study to predict the beetles' survival in its new range, the influence of climatic conditions on its egg development and reproductive performance were investigated in the laboratory. The threshold temperature (T°) and degree-days (DD) required for egg hatch were determined after exposing the eggs to various constant temperatures (12, 17, 22, 27 and 32°C) in separate growth chambers. The DD required for egg hatch was 178.6, and the temperature threshold required for egg hatch was 11.3°C. Survival of eggs varied from 27 to 56% at 32 and 17°C, respectively, and was optimum between 17 and 25°C. Oviposition was examined under high and low relative humidity (RH) regimes while egg hatch was determined at six RH levels, each maintained in a separate controlled growth chamber set at a constant temperature (25°C). Whilst RH had no influence on oviposition, eggs were highly susceptible to aridity, and continuous exposure to relative humidity below 63% for more than three days was wholly lethal at 25°C. Optimum egg hatch occurred at RH between 85 and 95% for up to 12 days. The effect of day length on oviposition and subsequent egg hatch was investigated under two photoperiod regimes. Neither oviposition nor subsequent egg hatch was influenced by photoperiod. The knowledge obtained will be useful for mass rearing as well as field release programmes for L. bethae.

scholarly journals Temperature thresholds for chlorine activation and ozone loss in the polar stratosphere

2012 ◽  
Vol 30 (7) ◽  
pp. 1055-1073 ◽  
Author(s):  
K. Drdla ◽  
R. Müller
Keyword(s):  
Potential Temperature ◽  
Volcanic Eruptions ◽  
Reaction Rates ◽  
Threshold Temperature ◽  
Temperature Threshold ◽  
Detailed Model ◽  
Ozone Loss ◽  
Polar Stratosphere ◽  
The Impact ◽  
Polar Ozone

Abstract. Low stratospheric temperatures are known to be responsible for heterogeneous chlorine activation that leads to polar ozone depletion. Here, we discuss the temperature threshold below which substantial chlorine activation occurs. We suggest that the onset of chlorine activation is dominated by reactions on cold binary aerosol particles, without the formation of polar stratospheric clouds (PSCs), i.e. without any significant uptake of HNO3 from the gas phase. Using reaction rates on cold binary aerosol in a model of stratospheric chemistry, a chlorine activation threshold temperature, TACL, is derived. At typical stratospheric conditions, TACL is similar in value to TNAT (within 1–2 K), the highest temperature at which nitric acid trihydrate (NAT) can exist. TNAT is still in use to parameterise the threshold temperature for the onset of chlorine activation. However, perturbations can cause TACL to differ from TNAT: TACL is dependent upon H2O and potential temperature, but unlike TNAT is not dependent upon HNO3. Furthermore, in contrast to TNAT, TACL is dependent upon the stratospheric sulfate aerosol loading and thus provides a means to estimate the impact on polar ozone of strong volcanic eruptions and some geo-engineering options, which are discussed. A parameterisation of TACL is provided here, allowing it to be calculated for low solar elevation (or high solar zenith angle) over a comprehensive range of stratospheric conditions. Considering TACL as a proxy for chlorine activation cannot replace a detailed model calculation, and polar ozone loss is influenced by other factors apart from the initial chlorine activation. However, TACL provides a more accurate description of the temperature conditions necessary for chlorine activation and ozone loss in the polar stratosphere than TNAT.

scholarly journals Extreme summer temperatures in Iberia: health impacts and associated synoptic conditions

2005 ◽  
Vol 23 (2) ◽  
pp. 239-251 ◽  
Author(s):  
R. García-Herrera ◽  
J. Díaz ◽  
R. M. Trigo ◽  
E. Hernández
Keyword(s):  
Extreme Values ◽  
Northern Africa ◽  
Temperature Fields ◽  
Threshold Temperature ◽  
Temperature Threshold ◽  
Daily Mortality ◽  
Heat Effects ◽  
Synoptic Conditions ◽  
Summer Temperatures ◽  
The Impact

Abstract. This paper examines the effect of extreme summer temperatures on daily mortality in two large cities of Iberia: Lisbon (Portugal) and Madrid (Spain). Daily mortality and meteorological variables are analysed using the same methodology based on Box-Jenkins models. Results reveal that in both cases there is a triggering effect on mortality when maximum daily temperature exceeds a given threshold (34°C in Lisbon and 36°C in Madrid). The impact of most intense heat events is very similar for both cities, with significant mortality values occurring up to 3 days after the temperature threshold has been surpassed. This impact is measured as the percentual increase of mortality associated to a 1°C increase above the threshold temperature. In this respect, Lisbon shows a higher impact, 31%, as compared with Madrid at 21%. The difference can be attributed to demographic and socio-economic factors. Furthermore, the longer life span of Iberian women is critical to explain why, in both cities, females are more susceptible than males to heat effects, with an almost double mortality impact value. The analysis of Sea Level Pressure (SLP), 500hPa geopotential height and temperature fields reveals that, despite being relatively close to each other, Lisbon and Madrid have relatively different synoptic circulation anomalies associated with their respective extreme summer temperature days. The SLP field reveals higher anomalies for Lisbon, but extending over a smaller area. Extreme values in Madrid seem to require a more western location of the Azores High, embracing a greater area over Europe, even if it is not as deep as for Lisbon. The origin of the hot and dry air masses that usually lead to extreme heat days in both cities is located in Northern Africa. However, while Madrid maxima require wind blowing directly from the south, transporting heat from Southern Spain and Northern Africa, Lisbon maxima occur under more easterly conditions, when Northern African air flows over the central Iberian plateau, which had been previously heated.

scholarly journals DISPARITIES IN DEPRESSION AMONG CHINESE OLDER ADULTS WITH NEURODEGENERATIVE DISEASES

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S879-S879
Author(s):  
Zhichao Hao ◽  
qingyi Li ◽  
Nicole Ruggiano
Keyword(s):  
Older Adults ◽  
Neurodegenerative Diseases ◽  
Incidence Rate ◽  
Research Policy ◽  
Activity Level ◽  
Policy And Practice ◽  
Chinese Older Adults ◽  
Healthy Longevity ◽  
Negative Impacts ◽  
Self Reported Health Status

Abstract Depression is a major health issue among older adults, and it exerts negative impacts on them physically and mentally. In turn, various factors facilitate or impede the occurrence of depression, socially, economically and culturally. At the same time, neurodegenerative diseases have become a leading cause of death and disability worldwide. In China, the incidence rate of Parkinson’s disease among older adults aged 65 and older is 1.7%, which means 100,000 new cases occur each year, more than 2.5 million in total. Meanwhile, 3.21% of incidence rate, more than 8 million older adults aged 65 and older with Alzheimer’s Disease and Related Dementia (AD/RD) makes China become the largest and fastest-growing area of AD/RD in the world. Around 2050, Chinese older adults with AD/RD will exceed 20 million. However, little is known about the extent that to which older adults with Parkinson’s or AD/RD in China will suffer from depression. This study was conducted on the latest wave (2011-2014) of the Chinese Longitudinal Healthy Longevity Survey (CLHLS, 1998-2014). The sample included 334 Chinese older adults aged 65 and older with neurodegenerative diseases (Parkinson’s or AD/RD). A univariate and binomial hierarchical logistic regression were performed. Result showed that 13.5% (n = 45) participants reported depression. Several covariates were significantly correlated with the occurrence of depression, including: co-residence of interviewee, activity level, level of chronic diseases, self-reported health status and Instrumental Activity of Daily Life. Implications for research, policy, and practice are discussed.

scholarly journals Calcium isotopic composition of high-latitude proxy carrier <I>Neogloboquadrina pachyderma</I> (sin.)

2007 ◽  
Vol 4 (5) ◽  
pp. 3301-3330 ◽  
Author(s):  
D. Hippler ◽  
R. Kozdon ◽  
K. F. Darling ◽  
A. Eisenhauer ◽  
T. F. Nägler
Keyword(s):  
Isotopic Composition ◽  
High Latitude ◽  
Isotope Composition ◽  
Planktonic Foraminifera ◽  
Threshold Temperature ◽  
Critical Threshold ◽  
Cool Water ◽  
Tropical Regions ◽  
Neogloboquadrina Pachyderma ◽  
Shell Carbonate

Abstract. The accurate reconstruction of sea surface temperature (SST) history in climate-sensitive regions (e.g. tropical and polar oceans) became a challenging task in palaeoceanographic research. However, biogenic shell carbonate SST proxies successfully developed for tropical regions often fail in cool water environments. Their major regional shortcomings and the cryptic diversity now found within the major high latitude proxy carrier Neogloboquadrina pachyderma (sin.) highlight an urgent need to develop complementary SST proxies for these cool water regions. Here we incorporate the genetic component into a calibration study of a new SST proxy for the high latitudes. We found that the calcium isotopic composition (δ44/40Ca) of calcite from genotyped net catches and core-top samples of the planktonic foraminifera Neogloboquadrina pachyderma (sin) is strongly related to temperature and unaffected by genetic variations. The temperature sensitivity has been found to be 0.17 (±0.04)‰ per 1°C highlighting its potential for downcore applications in open marine cool-water environments. Our results further indicate that however in extreme polar environments, below a critical threshold temperature of 2.0 (±0.5)°C and salinity of 33.0 (±0.5)‰ a prominent shift in biomineralization affect the Ca isotope composition of N. pachyderma (sin.) becoming insensitive to temperature. These findings highlight the need of systematic calibration studies to unravel the influencing factors on Ca isotope fractionation and to validate the proxies' applicability.

scholarly journals Dehydration risk, not ambient incubation, limits nest attendance at high temperatures

2020 ◽  
Author(s):  
Amanda R. Bourne ◽  
Amanda R. Ridley ◽  
Andrew E. McKechnie ◽  
Claire N. Spottiswoode ◽  
Susan J. Cunningham
Keyword(s):  
Nest Attendance ◽  
Doubly Labelled Water ◽  
Risk Of Death ◽  
Extreme Heat Events ◽  
Air Temperatures ◽  
Animal Populations ◽  
Hot Days ◽  
Negative Impacts ◽  
Semi Arid Region ◽  
Operative Temperatures

AbstractHigh air temperatures have measurable negative impacts on reproduction in wild animal populations, including during incubation in birds. Understanding the mechanisms driving these impacts requires comprehensive knowledge of animal physiology and behaviour under natural conditions. We used a novel combination of a non-invasive doubly-labelled water technique and behaviour observations in the field to examine effects of temperature, rainfall, and group size on physiology and behaviour during incubation in southern pied babblers Turdoides bicolor, a cooperatively-breeding passerine endemic to a semi-arid region in southern Africa. The proportion of time that clutches of eggs were incubated declined as air temperatures increased, traditionally interpreted as a benefit of ambient incubation. However, we show that a) clutches were less likely to hatch when exposed to high air temperatures; b) pied babbler groups incubated their nests almost constantly (97% of daylight hours) except on hot days; c) operative temperatures in unattended nests were substantially higher than air temperatures and frequently exceeded 40.5°C, above which bird embryos are at risk of death; d) pied babblers incubating for long periods of time failed to maintain water balance on hot days but not cool days; and e) pied babblers from incubating groups did not maintain body mass on hot days. These results suggest that, rather than taking advantage of opportunities for ambient incubation, pied babblers leave the nests during hot periods to avoid dehydration as a consequence of incubating at high operative temperatures. As mean air temperatures increase and extreme heat events become more frequent under climate change, birds will likely incur greater water costs during incubation, leading to compromised nest attendance and increased likelihood of eggs overheating, with implications for nest success and, ultimately, population persistence.

scholarly journals Calcium isotopic composition of high-latitude proxy carrier <i>Neogloboquadrina pachyderma</i> (sin.)

2009 ◽  
Vol 6 (1) ◽  
pp. 1-14 ◽  
Author(s):  
D. Hippler ◽  
R. Kozdon ◽  
K. F. Darling ◽  
A. Eisenhauer ◽  
T. F. Nägler
Keyword(s):  
Isotopic Composition ◽  
Temperature Sensitivity ◽  
High Latitude ◽  
Planktonic Foraminifera ◽  
Threshold Temperature ◽  
Critical Threshold ◽  
Cool Water ◽  
Tropical Regions ◽  
Neogloboquadrina Pachyderma ◽  
Species Specific

Abstract. The accurate reconstruction of sea surface temperature (SST) history in climate-sensitive regions (e.g. tropical and polar oceans) became a challenging task in palaeoceanographic research. Biogenic shell carbonate SST proxies successfully developed for tropical regions often fail in cool water environments. Their major regional shortcomings and the cryptic diversity now found within the major high latitude proxy carrier Neogloboquadrina pachyderma (sin.) highlight an urgent need to explore complementary SST proxies for these cool-water regions. Here we incorporate the genetic component into a calibration study of a new SST proxy for the high latitudes. We found that the calcium isotopic composition (δ44/40Ca) of calcite from genotyped net catches and core-top samples of the planktonic foraminifera Neogloboquadrina pachyderma (sin.) is related to temperature and unaffected by genetic variations. The temperature sensitivity has been found to be 0.17 (±0.02)‰ per 1°C, highlighting its potential for downcore applications in open marine cool-water environments. Our results further indicate that in extreme polar environments, below a critical threshold temperature of 2.0 (±0.5)°C associated with salinities below 33.0 (±0.5)‰, a prominent shift in biomineralization affects the δ44/40Ca of genotyped and core-top N. pachyderma (sin.), becoming insensitive to temperature. These findings highlight the need of more systematic calibration studies on single planktonic foraminiferal species in order to unravel species-specific factors influencing the temperature sensitivity of Ca isotope fractionation and to validate the proxies' applicability.

Sign in / Sign up

Export Citation Format

Share Document