scholarly journals Energy Expenditure and Water Turnover of Incubating Ruddy Turnstones: High Costs under High Arctic Climatic Conditions

The Auk ◽  
1994 ◽  
Vol 111 (2) ◽  
pp. 366-376 ◽  
Author(s):  
Theunis Piersma
1995 ◽  
Vol 16 (1) ◽  
pp. 55-66 ◽  
Author(s):  
Marcos Baez ◽  
Roland Vernet ◽  
Jacques Castanet

AbstractWater fluxes and daily energy expenditure (DEE) of Gallotia galloti, G. stehlini and G. atlantica, were estimated over a three-year period using the doubly-labelled water (DLW) method. Water influx varied little between seasons and between sexual categories. Juveniles tended to have higher water fluxes in spring in all three species; after a dry period the water turnover tended to decrease for all sexes in G. galloti and G. stehlini, whereas little variation was observed for G. atlantica. The average water influx, combined for all periods, was 46.27, 50.97 and 38.20 ml H2O.kg-1 d-1 for the three species respectively; only the last value differs significantly from the remaining two. The mean DEE, for all periods combined, were 189.7, 179.4 and 146.5 J g-1 d-1 for the three species respectively. As for water turnover, only the value for G. atlantica differed significantly. These data suggest that: G. atlantica may be better adaptated to maintain homeostasis during dry periods and that differences in interspecific DEE can also be explained by others factors than differences in habitat, climatic conditions, daily profiles of activity or body temperatures. We suspect that the incidence of intraspecific competition has more importance in G. atlantica than in the two other species.


1988 ◽  
Vol 66 (3) ◽  
pp. 555-561 ◽  
Author(s):  
Roland Vernet ◽  
Claude Grenot ◽  
Saïd Nouira

Water flux and daily energy expenditure were measured with doubly labeled water (3HH18O) in two insectivorous sympatric species of Lacertidae of Kerkennah islands (Tunisia), Eremias olivieri (mean body mass: 1.1 g) and Acanthodactylus pardalis (4.5 g) in a semiarid environment. Water turnover and field metabolic rate of Eremias olivieri (174 μL H2O g−1 d−1 and 250 J g−1 d−1) were, respectively, 2.5 and 5 times higher than those of Acanthodactylus pardalis (70 μL H2O g−1 d−1 and 52 J g−1 d−1). The water turnover of Eremias olivieri is one of the highest known among insectivorous lizards, and the daily energy expenditure of Acanthodactylus pardalis one of the lowest. The most plausible explanations are the differences in the size of the prey eaten by each species at this time of the season and in the duration of daily activity; the daily activity of Acanthodactylus pardalis is short (4.5 h d−1) although it is a sit-and-wait predator, whereas Eremias olivieri is active regularly every day for a longer period (7.5 h d−1) although it is an active forager. The high values of water turnover in Eremias olivieri suggest that food is not the only source of water for lizards in this particular insular environment.


Radiocarbon ◽  
2016 ◽  
Vol 59 (2) ◽  
pp. 489-503 ◽  
Author(s):  
E Zazovskaya ◽  
N Mergelov ◽  
V Shishkov ◽  
A Dolgikh ◽  
V Miamin ◽  
...  

AbstractThis article discusses radiocarbon dating results for soils and soil-like systems in the East Antarctic oases, including Schirmacher, Thala Hills, and Larsemann Hills. The organic matter of endolithic and hypolithic systems, soils of wind shelters, and soils under moss-algae vegetation were dated along with micro- and macroprofiles. Organic matter pools formed under extreme climatic conditions and originated not from vascular plants but from cryptogamic organisms, and photoautotrophic microbes have been identified within the oases of the East Antarctica. The organic matter of the most of East Antarctic soils is young and cannot reach a steady state because of the high dynamism in the soil cover due to active erosion. The oldest soil organic matter in East Antarctica was found in the soils formed in wind shelters and endolithic soil-like systems under the protection of consolidated rock surfaces. According to our data, the maximal duration for the formation of organic matter profiles within the oases of East Antarctica is ~500 yr, which is similar to the age determined for High Arctic soils in Eurasia. The absence of older soils, comparable with the Holocene deglaciation, can be due to the extreme conditions resulting in occasional catastrophic events that destroyed the soil organic horizons.


2011 ◽  
Vol 106 (S1) ◽  
pp. S158-S161 ◽  
Author(s):  
Øystein Ahlstrøm ◽  
Paula Redman ◽  
John Speakman

Hunting with dogs in winter conditions is practised in the Nordic countries. The present study aimed at determining daily energy expenditure (DEE) and body water turnover (BWT) by the doubly labelled water technique in eight hunting dogs (body-weight (BW) range 14–27 kg) working 3 h/d for 3 d ( − 6°C) on ground covered with 20–40 cm of loose snow, to provide information on energy and water requirements. The mean distance run during the hunting period was recorded by the global positioning system and averaged 19·4 km/d. DEE increased with increasing BW (P < 0·001) and varied between 7·20 and 16·6 MJ/d (mean 11·0 MJ/d) corresponding to 950–1350 kJ/kg BW0·75 per d (mean 1170 kJ/kg BW0·75 per d). The larger dogs tended to run longer than the smaller dogs and therefore spent more energy per kg BW0·75 but not significantly (P>0·05). DEE values determined were close to the values measured for hunting dogs running for 3 h/d in hot climates, suggesting that climate within the range of the two studies has little impact on energy expenditure per h running activity. Compared with the work of sled dogs per km travelled running on a track, the work performed by the hunting dogs was suggested to be higher when running in a loose snow layer. However, DEE was much lower because sled dogs ran for a longer distance each day. Mean BWT was 217 ml/kg BW0·75 or 19 ml/kJ metabolisable energy.


The Auk ◽  
2005 ◽  
Vol 122 (2) ◽  
pp. 479-496 ◽  
Author(s):  
Stéphane Menu ◽  
Gilles Gauthier ◽  
Austin Reed

Abstract The many hazards that await birds along their migratory routes may negatively affect their survival, especially among newly fledged young. We estimated survival of young Greater Snow Geese (Chen caerulescens atlantica) during fall migration from the High Arctic to temperate areas and examined factors affecting their survival over a five-year period, using two approaches. First, each year (1993–1997), we banded fledglings and adults in mid-August, just before their departure from Bylot Island in the High Arctic (Nunavut, Canada), and again at an important staging area 3,000 km to the south at the Cap Tourmente National Wildlife Area (Québec, Canada) in October; recovery data from those two banding periods allowed estimation of survival during fall migration. Second, we visually determined brood size of neck-banded females before and after the main portion of the migratory flight, to estimate survival of young. The two approaches yielded similar survival estimates and showed the same interannual variation, thus suggesting that estimates were reliable. Mortality of young shortly after fledging and during the fall migration was high, compared with that of adults (monthly survival 0.662 in young vs. 0.989 in adults). However, mortality of young after migration was similar to that of adults (monthly survival 0.969 in young vs. 0.972 in adults). Migration survival of young varied considerably among annual cohorts (range of 0.119–0.707 over five years), and most of the mortality appeared to be natural. Survival was especially low in years when (1) temperatures at time of fledging and start of migration were low (i.e. near or below freezing), (2) mean body mass of goslings near fledging was low, or (3) mean fledging date was late. Our results suggest that migration survival of young is affected by a combination of several factors (climatic conditions, body mass, and fledging date) and that survival is reduced when one of those factors intervenes.


2000 ◽  
Vol 278 (3) ◽  
pp. R669-R676 ◽  
Author(s):  
Michael Scantlebury ◽  
Waring Hynds ◽  
Derek Booles ◽  
John R. Speakman

Isotope-based techniques for the measurement of water turnover, energy expenditure, and milk intake often assume that there is no recycling of isotopes once they have left the labeled animal. In experiments involving lactating females or their suckling offspring, there are several possible routes of isotope recycling. These include the consumption of labeled milk by offspring, the ingestion of labeled excreta, and the rebreathing of exhaled labeled CO2 or water vapor by both mother and offspring. Isotope recycling might be especially important during lactation because the offspring are in close contact with each other and their mother for prolonged periods. We show here in 24- to 30-day-old domestic dog Canis familiarispuppies that there was no detectable transfer of 18O or2H from labeled to unlabeled pups in two litters (16 pups, 8 labeled, 8 unlabeled) that were weaned early and independent of their mother. However, there was a significant transfer of both isotopes from labeled to unlabeled pups and from labeled pups to their mothers in nine equivalent nursing litters of the same age (27 labeled, 26 unlabeled pups). The increases in enrichment of isotopes in unlabeled offspring were greater than the increases in enrichment of the mothers. This indicates that maternal ingestion of offspring excreta and subsequent transfer of isotope in milk is not the sole pathway of recycling. Additional routes must also be important, such as exchange of isotope between pups on saliva-coated nipples and perhaps direct ingestion of excreta by unweaned young. Recycling is unlikely to be an important factor when determining maternal metabolic rate during peak lactation in domestic dogs. However, experiments that are designed to assess the energy demands of pups and isotope-based estimates of water turnover in offspring may need to take into account any effects of isotope recycling. In a theoretical example, removing the effects of recycling increased the measured energy expenditure in pups by up to 7% and increased the calculated elimination rates of both isotopes by up to 11.1% in 18oxygen and 10.9% in2hydrogen.


1987 ◽  
Vol 33 (113) ◽  
pp. 123-128 ◽  
Author(s):  
Raymond S. Bradley ◽  
Mark C. Serreze

AbstractMass-balance measurements have been renewed on two small ice caps on north-eastern Ellesmere Island. Original stake networks were established in 1972 and 1976. Since then, both ice caps have experienced significant mass losses averaging –70 to –140 kg m−2a−1. They have also decreased in area. The equilibrium line in this area has averaged around 1150 m for the last decade or so. The ice caps are remnants of former climatic conditions and are out of equilibrium with contemporary climate.


2005 ◽  
Vol 93 (2) ◽  
pp. 199-203 ◽  
Author(s):  
Klaas R. Westerterp ◽  
Guy Plasqui ◽  
Annelies H. C. Goris

Although water is an important nutrient, there are no recommended intake values. Here, water intake, energy intake, physical activity and water loss was measured over 1 week in summer and in winter. Subjects were healthy volunteers, forty-two women and ten men, mean age of 29 (sd 7) years and mean BMI 21·8 (sd 2·2) kg/m2. Water intake was measured with a 7 d food and water record. Physical activity level (PAL) was observed as the ratio of total energy expenditure, as measured with doubly labelled water, to resting energy expenditure as measured in a respiration chamber. Water loss was measured with the deuterium elimination method. Water loss was highly reproducible and ranged from 0·20 to 0·35 l/MJ, independent of season and activity level, with higher values in women. Water loss was related to water and energy intake in summer (r 0·96, P<0·0001 and r 0·68, P<0·001, respectively) as well as in winter (r 0·98, P<0·0001 and r 0·63, P<0·01, respectively). Water loss was, for men, higher in subjects with a higher physical activity in summer (r 0·94, P<0·0001) and in winter (r 0·70, P<0·05). Normalizing water loss for differences in energy expenditure by expressing water loss in litres per MJ resulted in the same value for men in summer and winter. For women, physical activity-adjusted values of water loss were higher, especially in summer. In men, water turnover was determined by energy intake and physical activity, while seasonal effects appeared through energy expenditure. Women showed a higher water turnover that was unrelated to physical activity.


2012 ◽  
Vol 49 (8) ◽  
pp. 865-876 ◽  
Author(s):  
Jennifer Throop ◽  
Antoni G. Lewkowicz ◽  
Sharon L. Smith

Climate – ground temperature relations are examined under a range of conditions for 10 sites across northern Canada. The sites are located between 60°N and 83°N and at elevations of 40 to 1840 m above sea level. They encompass various environmental and climatic conditions, with permafrost temperatures that range from just below 0 to –15 °C. The substrates range from bedrock to fine-grained sediment with high ice content, and vegetation types include coniferous forests in the Mackenzie Valley, shrub tundra at high elevation in the southern Yukon Territory, and polar desert in the High Arctic. Permafrost conditions at all of these sites are determined primarily by air temperature, followed by snow and substrate conditions. The apparent thermal diffusivity is relatively high at colder sites and in bedrock and is lower at sites in sediment with high ice content. Snow has a greater influence on air–ground temperature relations at sites where mean annual air temperatures and active-layer moisture contents are relatively high, leading to physically significant latent heat effects and a slower freeze-back of the active layer.


REVISTARQUIS ◽  
2016 ◽  
Vol 5 (2) ◽  
Author(s):  
Kevin Rojas Varela

PresentaciónEste condominio/hotel fue proyectado bajo altos estándares de arquitectura bioclimática, diseñado para lograr un máximo confort con el mínimo gasto energético, aprovechando las condiciones climáticas del entorno mediante la transformación pasiva de elementos externos -viento, agua y vegetación-, en confort interno. Sumado a un diseño integral, que comprende desde la zonificación en función de vientos, soleamiento y topografía, hasta el diseño de fachadas y dispositivos para el manejo de condiciones climáticas dadas en el sitio. PresentationThis condo / hotel was designed under high standards of bioclimatic architecture design to achieve maximum comfort with the lowest energy expenditure, taking advantage of the climatic conditions of the environment by transforming passive external elements -wind, water and vegetation- to produce internal comfort. In addition to an integrated design, it considers zoning based on wind, sun exposure and topography as well as the design of facades and devices to control climatic conditions given on the site.


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