scholarly journals Avian mortality risk during heat waves will increase greatly in arid Australia during the 21st century

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Shannon R Conradie ◽  
Stephan M Woodborne ◽  
Blair O Wolf ◽  
Anaïs Pessato ◽  
Mylene M Mariette ◽  
...  
Keyword(s):  
21St Century ◽  
Mortality Risk ◽  
Heat Waves ◽  
Arid Zone ◽  
Climate Change Scenarios ◽  
Arid Environments ◽  
Zebra Finches ◽  
Tolerance Limits ◽  
Water Losses ◽  
Evaporative Water

Abstract Intense heat waves are occurring more frequently, with concomitant increases in the risk of catastrophic avian mortality events via lethal dehydration or hyperthermia. We quantified the risks of lethal hyperthermia and dehydration for 10 Australian arid-zone avifauna species during the 21st century, by synthesizing thermal physiology data on evaporative water losses and heat tolerance limits. We evaluated risks of lethal hyperthermia or exceedance of dehydration tolerance limits in the absence of drinking during the hottest part of the day under recent climatic conditions, compared to those predicted for the end of this century across Australia. Increases in mortality risk via lethal dehydration and hyperthermia vary among the species modelled here but will generally increase greatly, particularly in smaller species (~10–42 g) and those inhabiting the far western parts of the continent. By 2100 CE, zebra finches’ potential exposure to acute lethal dehydration risk will reach ~ 100 d y−1 in the far northwest of Australia and will exceed 20 d y−1 over > 50% of this species’ current range. Risks of dehydration and hyperthermia will remain much lower for large non-passerines such as crested pigeons. Risks of lethal hyperthermia will also increase substantially for smaller species, particularly if they are forced to visit exposed water sources at very high air temperatures to avoid dehydration. An analysis of atlas data for zebra finches suggests that population declines associated with very hot conditions are already occurring in the hottest areas. Our findings suggest that the likelihood of persistence within current species ranges, and the potential for range shifts, will become increasingly constrained by temperature and access to drinking water. Our model adds to an increasing body of literature suggesting that arid environments globally will experience considerable losses of avifauna and biodiversity under unmitigated climate change scenarios.

scholarly journals Mapping evaporative water loss in desert passerines reveals an expanding threat of lethal dehydration

2017 ◽  
Vol 114 (9) ◽  
pp. 2283-2288 ◽  
Author(s):  
Thomas P. Albright ◽  
Denis Mutiibwa ◽  
Alexander. R. Gerson ◽  
Eric Krabbe Smith ◽  
William A. Talbot ◽  
...  
Keyword(s):  
Water Loss ◽  
Environmental Changes ◽  
Temporal Dynamics ◽  
Heat Waves ◽  
Arid Zone ◽  
Evaporative Water Loss ◽  
Physiological Data ◽  
Passerine Birds ◽  
Evaporative Water ◽  
Thermal Refugia

Extreme high environmental temperatures produce a variety of consequences for wildlife, including mass die-offs. Heat waves are increasing in frequency, intensity, and extent, and are projected to increase further under climate change. However, the spatial and temporal dynamics of die-off risk are poorly understood. Here, we examine the effects of heat waves on evaporative water loss (EWL) and survival in five desert passerine birds across the southwestern United States using a combination of physiological data, mechanistically informed models, and hourly geospatial temperature data. We ask how rates of EWL vary with temperature across species; how frequently, over what areas, and how rapidly lethal dehydration occurs; how EWL and die-off risk vary with body mass; and how die-off risk is affected by climate warming. We find that smaller-bodied passerines are subject to higher rates of mass-specific EWL than larger-bodied counterparts and thus encounter potentially lethal conditions much more frequently, over shorter daily intervals, and over larger geographic areas. Warming by 4 °C greatly expands the extent, frequency, and intensity of dehydration risk, and introduces new threats for larger passerine birds, particularly those with limited geographic ranges. Our models reveal that increasing air temperatures and heat wave occurrence will potentially have important impacts on the water balance, daily activity, and geographic distribution of arid-zone birds. Impacts may be exacerbated by chronic effects and interactions with other environmental changes. This work underscores the importance of acute risks of high temperatures, particularly for small-bodied species, and suggests conservation of thermal refugia and water sources.

scholarly journals Avian thermoregulation in the heat: is evaporative cooling more economical in nocturnal birds?

2018 ◽  
Author(s):  
Ryan S. O’Connor ◽  
Ben Smit ◽  
William A. Talbot ◽  
Alexander R. Gerson ◽  
R. Mark Brigham ◽  
...  
Keyword(s):  
Heat Dissipation ◽  
Heat Waves ◽  
Evaporative Cooling ◽  
Evaporative Heat Loss ◽  
Arid Environments ◽  
Evaporative Water ◽  
Air Temperatures ◽  
Nocturnal Species ◽  
Diurnal Species ◽  
Intense Heat

AbstractEvaporative cooling is a prerequisite for avian occupancy of hot, arid environments, and is the only avenue of heat dissipation when air temperatures (Ta) exceed body temperature (Tb). Whereas diurnal birds can potentially rehydrate throughout the day, nocturnal species typically forgo drinking between sunrise and sunset. We hypothesized that nocturnal birds have evolved reduced rates of evaporative water loss (EWL) and more economical evaporative cooling mechanisms than those of diurnal species that permit them to tolerate extended periods of intense heat without becoming lethally dehydrated. We used phylogenetically-informed regressions to compare EWL and evaporative cooling efficiency (ratio of evaporative heat loss [EHL] and metabolic heat production [MHP]; EHL/MHP) among nocturnal and diurnal birds at high Ta. We analyzed variation in three response variables: 1) slope of EWL at Tabetween 40 and 46°C, 2) EWL at Ta= 46°C, and 3) EHL/MHP at Ta= 46°C. Nocturnality emerged as a weak, negative predictor, with nocturnal species having slightly shallower slopes and reduced EWL compared to diurnal species of similar mass. In contrast, nocturnal activity was positively correlated with EHL/MHP, indicating a greater capacity for evaporative cooling in nocturnal birds. However, our analysis also revealed conspicuous differences among nocturnal taxa. Caprimulgids and Australian-owlet nightjars had shallower slopes and reduced EWL compared to similarly-sized diurnal species, whereas owls had EWL rates comparable to diurnal species. Consequently, our results did not unequivocally demonstrate more economical cooling among nocturnal birds. Owls predominately select refugia with cooler microclimates, but the more frequent and intense heat waves forecast for the 21stcentury may increase microclimate temperatures and the necessity for active heat dissipation, potentially increasing owls’ vulnerability to dehydration and hyperthermia.

scholarly journals Assessment of water resources of the Ukrainian rivers according to the average statistical models of climate change trajectories RCP4.5 and RCP8.5 over the period of 2021 to 2050

2020 ◽  
pp. 93-104
Author(s):  
N. S. Loboda ◽  
M. O. Kozlov
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Statistical Model ◽  
21St Century ◽  
Arid Zone ◽  
Climate Change Scenarios ◽  
The South ◽  
Change Trajectories ◽  
The North ◽  
Semi Arid

The relevance of the presented work is due to the necessity of assessment of a possible state of Ukrainian water resources in the 21st century according to climate change scenarios in order to justify the strategy of economic development. The research object is presented by water resources of the Ukrainian rivers. The research focuses on the effects of global warming on Ukrainian water resources in 2021-2050. The work aims at assessing a possible impact of climate change on Ukrainian water resources in the 21st century, using the data from the climate change trajectories RCP4.5 and RCP8.5 over the period of 2021 to 2050. Calculations of water resources over the period of 2021 to 2050 are performed according to the average statistical model from the ensemble consisting of 14 climatic models of the CORDEX experiment for the RCP4.5 and RCP8.5 trajectories. Water resources are assessed based on the Climate-runoff model developed by OSENU. The result of such calculations is the evaluation of moisture and heat resources, as well as water resources in the natural conditions of their formation. Natural (undisturbed by water management) average long-term annual runoff determined by the meteorological data is usually called "a climatic runoff". The accuracy of climatic runoff calculations using the map of isolines is ±10%. The calculations are performed in the grid nodes. The geographical location of the selected nodes corresponds to the location of meteorological stations the total number of which is 115. Evaluation of heat, moisture and water resources changes was performed by comparing the calculated values and the basic ones. The climatic runoff for the period of observations before 1989 is thought to be basic. According to the average statistical model of the RCP4.5 trajectory over the period of 2021 to 2050, the expansion of the semi-arid zone and insufficient humidification zone to the north is to be expected (when compared to the basic period). The insufficient humidification zone will expand to the northwest displacing the sufficient humidification zone. The reduction of water resources will reach to minus 40-50% in the south of the country and to 0% - minus 10% in the north. The area of water resources growth will be preserved in the Ukrainian Carpathians. Comparing to the RCP4.5 the RCP8.5 trajectory is considered to be more “rigid” in relation to the state of Ukrainian water resources. The reduction of water resources will occur on the nearly entire territory, except Bukovyna, due to the increase of arid climate. Water resources will decrease to minus 50-60% in the south and to minus 30% in the north. Both RCP4.5 and RCP8.5 trajectories offer a forecast of water resources that is unfavourable for the development of Ukrainian economy, as it will cause expansion of both semi-arid and insufficient humidification zones. This will increase the water resources shortage in Ukraine.

scholarly journals Chronic, sublethal effects of high temperatures will cause severe declines in southern African arid-zone birds during the 21st century

2019 ◽  
Vol 116 (28) ◽  
pp. 14065-14070 ◽  
Author(s):  
Shannon R. Conradie ◽  
Stephan M. Woodborne ◽  
Susan J. Cunningham ◽  
Andrew E. McKechnie
Keyword(s):  
Body Mass ◽  
21St Century ◽  
Sublethal Effects ◽  
Heat Waves ◽  
Arid Zone ◽  
Heat Exposure ◽  
Fitness Costs ◽  
Breeding Failure ◽  
Hot Weather ◽  
Using Data

Birds inhabiting hot, arid regions are among the terrestrial organisms most vulnerable to climate change. The potential for increasingly frequent and intense heat waves to cause lethal dehydration and hyperthermia is well documented, but the consequences of sublethal fitness costs associated with chronic exposure to sustained hot weather remain unclear. Using data for species occurring in southern Africa’s Kalahari Desert, we mapped exposure to acute lethal risks and chronic sublethal fitness costs under past, present, and future climates. For inactive birds in shaded microsites, the risks of lethal dehydration and hyperthermia will remain low during the 21st century. In contrast, exposure to conditions associated with chronic, sublethal costs related to progressive body mass loss, reduced nestling growth rates, or increased breeding failure will expand dramatically. For example, by the 2080s the region will experience 10–20 consecutive days per year on which Southern Pied Babblers (Turdoides bicolor) will lose ∼4% of body mass per day, conditions under which this species’ persistence will be extremely unlikely. Similarly, exposure to air temperature maxima associated with delayed fledging, reduced fledgling size, and breeding failure will increase several-fold in Southern Yellow-billed Hornbills (Tockus leucomelas) and Southern Fiscals (Lanius collaris). Our analysis reveals that sublethal costs of chronic heat exposure are likely to drive large declines in avian diversity in the southern African arid zone by the end of the century.

scholarly journals Effects of Heat Waves During Post-natal Development on Mitochondrial and Whole Body Physiology: An Experimental Study in Zebra Finches

2021 ◽  
Vol 12 ◽  
Author(s):  
Riccardo Ton ◽  
Antoine Stier ◽  
Christine E. Cooper ◽  
Simon C. Griffith
Keyword(s):  
Body Temperature ◽  
Early Life ◽  
Heat Waves ◽  
Coupling Efficiency ◽  
Cellular Level ◽  
Whole Body ◽  
Zebra Finches ◽  
Evaporative Water ◽  
Early Life Exposure ◽  
Animal Metabolism

Human-induced climate change is increasing the frequency, duration, and intensity of heat waves and exposure to these extreme temperatures impacts individual physiology and performance (e.g., metabolism, water balance, and growth). These traits may be susceptible to thermal conditions experienced during embryonic development, but experiments focusing on post-natal development are scant. Documented effects of heat waves on whole-body metabolism may reflect changes in mitochondrial function, but most studies do not measure physiological traits at both the cellular and whole organism levels. Here, we exposed nests of zebra finches to experimentally simulated heat waves for 18 days after hatching and measured body mass, growth rate, whole-body metabolic rate, body temperature, wet thermal conductance, evaporative water loss, and relative water economy of chicks at three ages corresponding to ectothermic (day 5), poikilothermic (day 12), and homoeothermic (day 50) stages. Additionally, we measured mitochondrial bioenergetics of blood cells 80 days post-hatch. While early-life exposure to heat wave conditions did not impact whole body metabolic and hygric physiology, body temperature was lower for birds from heated compared with control nests at both 12 and 50 days of age. There was also an effect of nest heating at the cellular level, with mitochondria from heated birds having higher endogenous and proton-leak related respiration, although oxidative phosphorylation, maximum respiratory capacity, and coupling efficiency were not impacted. Our results suggest that early-life exposure to high ambient temperature induces programming effects on cellular-level and thermal physiology that may not be apparent for whole-animal metabolism.

scholarly journals The ship of the desert. The dromedary camel (Camelus dromedarius), a domesticated animal species well adapted to extreme conditions of aridness and heat

Rangifer ◽  
1990 ◽  
Vol 10 (3) ◽  
pp. 231 ◽  
Author(s):  
S. Bornstein
Keyword(s):  
Animal Species ◽  
Physiological Adaptation ◽  
Dromedary Camel ◽  
Large Animal ◽  
Water Losses ◽  
Evaporative Water ◽  
Ambient Temperatures ◽  
Adaptive Mechanisms ◽  
Adaptation To Heat ◽  
Arabian Camel

The dromedary camel (Camel dromedarius) is extremely well adapted to life in hot and arid lands. In terms of physiological adaptation to heat and water deprivation it surpasses by far every other large animal of which data have been collected. None of the adaptive mechanisms to cope with the environmental stresses are unique to the Arabian camel, but the efficiency of its adaptation is superior. At high ambient temperatures the camels adapt to the scarcity of water by reducing their faecal, urinary and evaporative water losses. During dehydration, the kidneys reduce water losses both by decreasing the glomerual filtration rate and by increasing the tubular reabsorption of water. Also their ability of regulating their body temperature from 34.5-40.7 °C conserves a lot of water, when most needed.

scholarly journals PROJECTION OF INCIDENT SURFACE SOLAR RADIATION IN CHINA UNDER A CLIMATE CHANGE SCENARIO

2019 ◽  
Vol XLII-3/W9 ◽  
pp. 187-194
Author(s):  
Y. K. Xiao ◽  
Z. M. Ji ◽  
C. S. Fu ◽  
W. T. Du ◽  
J. H. Yang ◽  
...  
Keyword(s):  
Climate Change ◽  
Solar Radiation ◽  
21St Century ◽  
Weighted Average ◽  
Global Climate Models ◽  
Future Climate Change ◽  
The Tibetan Plateau ◽  
Climate Change Scenarios ◽  
Model Ensemble ◽  
Surface Solar Radiation

Abstract. We projected incident surface solar radiation (SSR) over China in the middle (2040–2059) and end (2080–2099) of the 21st century in the Representative Concentration Pathway (RCP) 8.5 scenario using a multi-model ensemble derived from the weighted average of seven global climate models (GCMs). The multi-model ensemble captured the contemporary (1979–2005) spatial and temporal characteristics of SSR and reproduced the long-term temporal evolution of the mean annual SSR in China. However, it tended to overestimate values compared to observations due to the absence of aerosol effects in the simulations. The future changes in SSR showed increases over eastern and southern China, and decreases over the Tibetan Plateau (TP) and northwest China relative to the present day. At the end of the 21st century, there were SSR increases of 9–21 W m−2 over northwest, central, and south China, and decreases of 18–30 W m−2 over the TP in June–July–August (JJA). In northeast China, SSR showed seasonal variation with increases in JJA and decreases in December–January–February. The time series of annual SSR had a decreased linear trend for the TP, and a slightly increased trend for China during 2006–2099. The results of our study suggest that solar energy resources will likely decrease in the TP under future climate change scenarios.

scholarly journals Monitoring canopy and air temperature of dominant vegetation in tropical semi-arid using bioclimatic model

2016 ◽  
Vol 1 (1) ◽  
pp. 1-12
Author(s):  
Josiclêda Domiciano Galvíncio ◽  
Rejane Magalhães de Mendonça Pimentel
Keyword(s):  
Climate Change ◽  
Air Temperature ◽  
Dominant Species ◽  
Canopy Temperature ◽  
Leaf Temperature ◽  
Climate Change Scenarios ◽  
Arid Environments ◽  
Intergovernmental Panel ◽  
Dry Land ◽  
Bioclimatic Model

Typical vegetation of arid environments consists of few dominant species highly threatened by climate change. Jurema preta (Mimosa tenuiflora (Willd.) Poiret) is one of these successful species that now is dominant in extensive semiarid areas in the world. The development of a simple bioclimatic model using climate change scenarios based on optimistic and pessimistic predictions of the Intergovernmental Panel on Climate Change (IPCC) shown as a simple tool to predict possible responses of dominant species under dry land conditions and low functional biodiversity. The simple bioclimatic model proved satisfactory in creating climate change scenarios and impacts on the canopy temperature of Jurema preta in semiarid Brazil. The bioclimatic model was efficient to obtain spatially relevant estimations of air temperature from determinations of the surface temperature using satellite images. The model determined that the average difference of 5oC between the air temperature and the leaf temperature for Jurema preta, and an increase of 3oC in air temperature, promote an increase of 2oC in leaf temperature. It leads to disturbances in vital physiological mechanisms in the leaf, mainly the photosynthesis and efficient use of water.

scholarly journals Evaporative Water Losses of Some Small Australian Lizards

Ecology ◽  
1966 ◽  
Vol 47 (4) ◽  
pp. 589-594 ◽  
Author(s):  
William R. Dawson ◽  
Vaughan H. Shoemaker ◽  
Paul Licht
Keyword(s):  
Water Losses ◽  
Evaporative Water

scholarly journals Climate Scenarios and Agricultural Indices: A Case Study for Switzerland

Atmosphere ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 535
Author(s):  
Flavian Tschurr ◽  
Iris Feigenwinter ◽  
Andreas M. Fischer ◽  
Sven Kotlarski
Keyword(s):  
21St Century ◽  
Agricultural Sector ◽  
Heat Waves ◽  
Climate Scenario ◽  
Climate Variables ◽  
Climate Scenarios ◽  
High Emission ◽  
Projection Analysis ◽  
Horizontal Pattern

The CH2018 Climate Scenarios for Switzerland are evaluated with respect to the representation of 24 indices with agricultural relevance. Furthermore, future projections of the considered indices until the end of the 21st century are analyzed for two greenhouse gas scenarios (Representative Concentrations Pathways RCP2.6 and RCP8.5). The validation reveals good results for indices that are based on one or two climate variables only and on simple temporal aggregations. Indices that involve multiple climate variables, complex temporal statistics or extreme conditions are less well represented. The climate projection analysis indicates an intensification of temperature-related extreme events such as heat waves. In general, climate change signals in the indices considered are subject to three main patterns: a horizontal pattern across Switzerland, a vertical pattern depending on elevation and a temporal pattern with an intensification of change in the course of the 21st century. Changes are in most cases more pronounced for the high-emission RCP8.5 scenario compared to the mitigation scenario RCP2.6. Overall, the projections indicate a challenging 21st century climate for the agricultural sector. Our findings furthermore show the value and the necessity of a robust validation of climate scenario products to enable trustworthy and valuable impact analyses, especially for more complex indices and models.

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