scholarly journals Metabolic constraints on long-distance migration in birds

1996 ◽  
Vol 199 (1) ◽  
pp. 57-64 ◽  
Author(s):  
M Klaassen
Keyword(s):  
Water Balance ◽  
Water Loss ◽  
Physiological Stress ◽  
Plasma Osmolality ◽  
Large Species ◽  
Long Distance ◽  
Flight Behaviour ◽  
Flight Range ◽  
Ecological Barriers ◽  
Balance Problems

The flight range of migrating birds depends crucially on the amount of fuel stored by the bird prior to migration or taken up en route at stop-over sites. However, an increase in body mass is associated with an increase in energetic costs, counteracting the benefit of fuel stores. Water imbalance, occurring when water loss exceeds metabolic water production, may constitute another less well recognised problem limiting flight range. The main route of water loss during flight is via the lungs; the rate of loss depends on ambient temperature, relative humidity and ventilatory flow and increases with altitude. Metabolite production results in an increased plasma osmolality, also endangering the proper functioning of the organism during flight. Energetic constraints and water-balance problems may interact in determining several aspects of flight behaviour, such as altitude of flight, mode of flight, lap distance and stop-over duration. To circumvent energetic and water-balance problems, a bird could migrate in short hops instead of long leaps if crossing of large ecological barriers can be avoided. However, although necessitating larger fuel stores and being more expensive, migration by long leaps may sometimes be faster than by short hops. Time constraints are also an important factor in explaining why soaring, which conserves energy and water, occurs exclusively in very large species: small birds can soar at low speeds only. Good navigational skills involving accurate orientation and assessment of altitude and air and ground speed assist in avoiding physiological stress during migration.

scholarly journals Water Balance During Real and Simulated Long-Distance Migratory Flight in the Bar-Tailed Godwit

The Condor ◽  
2000 ◽  
Vol 102 (3) ◽  
pp. 645-652 ◽  
Author(s):  
Mėta M. Landys ◽  
Theunis Piersma ◽  
G. Henk Visser ◽  
Joop Jukema ◽  
Arnold Wijker
Keyword(s):  
Water Balance ◽  
Wadden Sea ◽  
Free Access ◽  
Model Output ◽  
Long Distance ◽  
Theoretical Simulation ◽  
Migratory Flight ◽  
Body Drag ◽  
Flight Range ◽  
Access To Water

Abstract We examined Bar-tailed Godwits (Limosa lapponica), a long-distance migratory shorebird, for evidence of dehydration toward the end of their 4,300-km migratory flight from West Africa to the Dutch Wadden Sea. Bar-tailed Godwits are ideal subjects for research on flight range constraints because they can readily be caught in migratory flight. Because godwits are capable of long nonstop travel, we hypothesized that they are physiologically adapted to minimize en route water loss, and therefore, do not experience water imbalance under standard migratory conditions. To test this hypothesis, we compared the hydration state of flying Bar-tailed Godwits at the end of a long bout of migratory flight to that of recently-landed godwits. Flying godwits were hydrated to the same degree as birds with free access to water, suggesting that godwits maintain water balance during migratory flight. To corroborate these empirical results, we ran a theoretical simulation of flight-incurred loss of water and energy in a male Bar-tailed Godwit based on the published model by Klaassen et al. (1999). When a low body drag is assumed, model output suggests that Bar-tailed Godwits flying at altitudes ranging from sea level to 3,000 m will avoid dehydration, and that flight at about 3,000 m will result in the longest possible flight range.

scholarly journals Great flights by great snipes: long and fast non-stop migration over benign habitats

2011 ◽  
Vol 7 (6) ◽  
pp. 833-835 ◽  
Author(s):  
Raymond H. G. Klaassen ◽  
Thomas Alerstam ◽  
Peter Carlsson ◽  
James W. Fox ◽  
Åke Lindström
Keyword(s):  
Migratory Birds ◽  
Strenuous Exercise ◽  
Migration Route ◽  
Long Distance ◽  
Migration Strategy ◽  
Ice Caps ◽  
Fuel Loads ◽  
Stopover Sites ◽  
Ecological Barriers ◽  
Suitable Habitats

Migratory land birds perform extreme endurance flights when crossing ecological barriers, such as deserts, oceans and ice-caps. When travelling over benign areas, birds are expected to migrate by shorter flight steps, since carrying the heavy fuel loads needed for long non-stop flights comes at considerable cost. Here, we show that great snipes Gallinago media made long and fast non-stop flights (4300–6800 km in 48–96 h), not only over deserts and seas but also over wide areas of suitable habitats, which represents a previously unknown migration strategy among land birds. Furthermore, the great snipes achieved very high ground speeds (15–27 m s −1 ), which was not an effect of strong tailwind support, and we know of no other animal that travels this rapidly over such a long distance. Our results demonstrate that some migratory birds are prepared to accept extreme costs of strenuous exercise and large fuel loads, even when stopover sites are available along the route and there is little tailwind assistance. A strategy of storing a lot of energy before departure, even if migration is over benign habitats, may be advantageous owing to differential conditions of fuel deposition, predation or infection risk along the migration route.

scholarly journals Improving the Keeping Quality and Vase Life of Cut Alstroemeria Flowers by Pre and Post-harvest Salicylic Acid Treatments

2013 ◽  
Vol 5 (3) ◽  
pp. 364-370 ◽  
Author(s):  
Elnaz SOLEIMANY-FARD ◽  
Khodayar HEMMATI ◽  
Ahmad KHALIGHI
Keyword(s):  
Salicylic Acid ◽  
Water Balance ◽  
Chlorophyll Content ◽  
Water Loss ◽  
Vase Life ◽  
Total Chlorophyll ◽  
Cut Flowers ◽  
Fresh Weight ◽  
Total Chlorophyll Content ◽  
Keeping Quality

Keeping quality and length of vase life are important factors for evaluation of cut flowers quality, for both domestic and export markets. Studding the effect of pre- and post-harvest salicylic acid applications on keeping quality and vase life of cut alstroemeria flowers during vase period is the approach taken. Aqueous solutions of salicylic acid at 0.0 (with distilled water), 1, 2 and 3 mM were sprayed to run-off (approximately 500 mL per plant), about two weeks before flowers harvest. The cut flowers were harvested in the early morning and both of cut flowers treated (sprayed) and untreated were kept in vase solutions containing salicylic acid at 0.0 (with distilled water), 1, 2 and 3 mM. Sucrose at 4% was added to all treatments as a base solution. The changes in relative fresh weight, water uptake, water loss, water balance, total chlorophyll content and vase life were estimated during vase period. The results showed that the relative fresh weight, water uptake, water balance, total chlorophyll content and vase life decreased significantly while the water loss increased significantly during experiment for all treatments. A significant difference between salicylic acid and control treatments in all measured parameters is observed. During vase period, the salicylic acid treatments maintained significantly a more favourable relative fresh weight, water uptake, water balance, total chlorophyll content and supressed significantly water loss, as compared to control treatment. Also, the results showed that the using salicylic acid increased significantly the vase life cut alstroemeria flowers, over control. The highest values of measured parameters were found when plants were treated by pre + post-harvest application of salicylic acid at 3 mM. The result revealed that the quality attributes and vase life of cut alstroemeria flowers were improved by the use of salicylic acid treatment.

scholarly journals Design and Fabrication of Small Vertical-Take-Off-Landing Unmanned Aerial Vehicle

2018 ◽  
Vol 152 ◽  
pp. 02023 ◽  
Author(s):  
Yasir Ashraf Abd Rahman ◽  
Mohammad Taghi Hajibeigy ◽  
Abdulkareem Shafiq Mahdi Al-Obaidi ◽  
Kean How Cheah
Keyword(s):  
Design Methodology ◽  
The Other ◽  
Long Distance ◽  
Open Spaces ◽  
Flight Tests ◽  
Flight Range ◽  
Horizontal Flight ◽  
Vtol Uav ◽  
Aerial Vehicle ◽  
Horizontal Thrust

Modern UAVs available in the market have well-developed to cater to the countless field of application. UAVs have their own limitations in terms of flight range and manoeuvrability. The traditional fixed-wing UAVs can fly for long distance but require runways or wide-open spaces for take-off and landing. On the other hand, the more trending multirotor UAVs are extremely manoeuvrable but cannot be used for long-distance flights because of their slower speeds and relatively higher consumption of energy. This study proposed the implementation of hybrid VTOL UAV which has the manoeuvring advantage of a multirotor UAV while having the ability to travel fast to reach a further distance. The design methodology and fabrication method are discussed extensively which would be followed by a number of flight tests to prove the concept. The proposed UAV would be equipped with quadcopter motors and a horizontal thrust motor for vertical and horizontal flight modes respectively.

scholarly journals Flight range, fuel load and the impact of climate change on the journeys of migrant birds

2018 ◽  
Vol 285 (1873) ◽  
pp. 20172329 ◽  
Author(s):  
Christine Howard ◽  
Philip A. Stephens ◽  
Joseph A. Tobias ◽  
Catherine Sheard ◽  
Stuart H. M. Butchart ◽  
...  
Keyword(s):  
Climate Change ◽  
Bird Species ◽  
Climate Impact ◽  
Fuel Load ◽  
Migratory Species ◽  
Long Distance ◽  
Avian Flight ◽  
Flight Range ◽  
Combine Information ◽  
The Impact

Climate change is predicted to increase migration distances for many migratory species, but the physiological and temporal implications of longer migratory journeys have not been explored. Here, we combine information about species' flight range potential and migratory refuelling requirements to simulate the number of stopovers required and the duration of current migratory journeys for 77 bird species breeding in Europe. Using tracking data, we show that our estimates accord with recorded journey times and stopovers for most species. We then combine projections of altered migratory distances under climate change with models of avian flight to predict future migratory journeys. We find that 37% of migratory journeys undertaken by long-distance migrants will necessitate an additional stopover in future. These greater distances and the increased number of stops will substantially increase overall journey durations of many long-distance migratory species, a factor not currently considered in climate impact studies.

Evolution of water balance in the genusDrosophila

2001 ◽  
Vol 204 (13) ◽  
pp. 2331-2338 ◽  
Author(s):  
Allen G. Gibbs ◽  
Luciano M. Matzkin
Keyword(s):  
Water Balance ◽  
Water Loss ◽  
The Body ◽  
The Other ◽  
Arid Environments ◽  
Physiological Mechanisms ◽  
Dehydration Tolerance ◽  
Cactophilic Drosophila ◽  
Adaptive Mechanisms ◽  
The World

SUMMARYFruit flies of the genus Drosophila have independently invaded deserts around the world on numerous occasions. To understand the physiological mechanisms allowing these small organisms to survive and thrive in arid environments, we performed a phylogenetic analysis of water balance in Drosophila species from different habitats. Desert (cactophilic) species were more resistant to desiccation than mesic ones. This resistance could be accomplished in three ways: by increasing the amount of water in the body, by reducing rates of water loss or by tolerating the loss of a greater percentage of body water (dehydration tolerance). Cactophilic Drosophila lost water less rapidly and appeared to be more tolerant of low water content, although males actually contained less water than their mesic congeners. However, when the phylogenetic relationships between the species were taken into account, greater dehydration tolerance was not correlated with increased desiccation resistance. Therefore, only one of the three expected adaptive mechanisms, lower rates of water loss, has actually evolved in desert Drosophila, and the other apparently adaptive difference between arid and mesic species (increased dehydration tolerance) instead reflects phylogenetic history.

The Effectiveness of Evapotranspiration Systems in Disposing of Wastewater in Remote Aboriginal Communities in Northwest Australia

1991 ◽  
Vol 23 (10-12) ◽  
pp. 1825-1833
Author(s):  
D. R. McGrath ◽  
G. E. Ho ◽  
K. Mathew
Keyword(s):  
Water Balance ◽  
Water Loss ◽  
Balance Equation ◽  
Eucalyptus Camaldulensis ◽  
Bare Soil ◽  
Pan Evaporation ◽  
Aboriginal Communities ◽  
Water Balance Equation ◽  
Northwest Australia

The potential usage of Evapotranspiration (ET) systems in remote Aboriginal communities was investigated. ET system sizing requirements were determined from the water balance equation. Water loss from lysimeters planted with trees (Eucalyptus camaldulensis) or lawn grass and from bare soil and gravel was monitored over several months and compared to pan evaporation measured during the same period. It was found that ET from bare soil and grass followed similar trends to pan evaporation, ranging from 30-60% of pan evaporation for soil and from 60-80% of pan evaporation for grass. ET rates increased in the tanks planted with trees as the plants grew and exceeded pan evaporation rates. Evaporation from gravel-filled lysimeters was low, being as little as 10% of pan evaporation.

scholarly journals Slaves of the environment: the movement of herbivorous insects in relation to their ecology and genotype

1999 ◽  
Vol 354 (1388) ◽  
pp. 1479-1495 ◽  
Author(s):  
Hugh D. Loxdale ◽  
Gugs Lushai
Keyword(s):  
Spatial Scale ◽  
Large Population ◽  
Insect Population ◽  
Insect Species ◽  
Herbivorous Insect ◽  
Suitable Habitat ◽  
Long Distance ◽  
Flight Behaviour ◽  
Vast Number ◽  
Insect Movement

The majority of insect species do not show an innate behavioural migration, but rather populations expand into favourable new habitats or contract away from unfavourable ones by random changes of spatial scale. Over the past 50 years, the scientific fascination with dramatic long–distance and directed mass migratory events has overshadowed the more universal mode of population movement, involving much smaller stochastic displacement during the lifetime of the insects concerned. This may be limiting our understanding of insect population dynamics. In the following synthesis, we provide an overview of how herbivorous insect movement is governed by both abiotic and biotic factors, making these animals essentially ‘slaves of their environment’. No displaced insect or insect population can leave a resource patch, migrate and flourish, leaving descendants, unless suitable habitat and/or resources are reached during movement. This must have constrained insects over geological time, bringing about species–specific adaptation in behaviour and movements in relation to their environment at a micro– and macrogeographical scale. With insects that undergo long–range spatial displacements, e.g. aphids and locusts, there is presumably a selection against movement unless overruled by factors, such as density–dependent triggering, which cause certain genotypes within the population to migrate. However, for most insect species, spatial changes of scale and range expansion are much slower and may occur over a much longer time–scale, and are not innate (nor directed). Ecologists may say that all animals and plants are figuratively speaking ‘slaves of their environments’, in the sense that their distribution is defined by their ecology and genotype. But in the case of insects, a vast number must perish daily, either out at sea or over other hostile habitats, having failed to find suitable resources and/or a habitat on which to feed and reproduce. Since many are blown by the vagaries of the wind, their chances of success are serendipitous in the extreme, especially over large distances. Hence, the strategies adopted by mass migratory species (innate pre–programmed flight behaviour, large population sizes and/or fast reproduction), which improve the chances that some of these individuals will succeed. We also emphasize the dearth of knowledge in the various interactions of insect movement and their environment, and describe how molecular markers (protein and DNA) may be used to examine the details of spatial scale over which movement occurs in relation to insect ecology and genotype.

scholarly journals Water Regulation in Cyanobacterial Biocrusts from Drylands: Negative Impacts of Anthropogenic Disturbance

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 720 ◽  
Author(s):  
Yolanda Cantón ◽  
Sonia Chamizo ◽  
Emilio Rodriguez-Caballero ◽  
Roberto Lázaro ◽  
Beatriz Roncero-Ramos ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Balance ◽  
Soil Water ◽  
Water Loss ◽  
Spatial Scales ◽  
Arid Ecosystems ◽  
Rainfall Simulation ◽  
Water Regulation ◽  
Natural Rainfall ◽  
Bare Soils

Arid and semi-arid ecosystems are characterized by patchy vegetation and variable resource availability. The interplant spaces of these ecosystems are very often covered by cyanobacteria-dominated biocrusts, which are the primary colonizers of terrestrial ecosystems and key in facilitating the succession of other biocrust organisms and plants. Cyanobacterial biocrusts regulate the horizontal and vertical fluxes of water, carbon and nutrients into and from the soil and play crucial hydrological, geomorphological and ecological roles in these ecosystems. In this paper, we analyze the influence of cyanobacterial biocrusts on water balance components (infiltration-runoff, evaporation, soil moisture and non-rainfall water inputs (NRWIs)) in representative semiarid ecosystems in southeastern Spain. The influence of cyanobacterial biocrusts, in two stages of their development, on runoff-infiltration was studied by rainfall simulation and in field plots under natural rainfall at different spatial scales. Results showed that cover, exopolysaccharide content, roughness, organic carbon, total nitrogen, available water holding capacity, aggregate stability, and other properties increased with the development of the cyanobacterial biocrust. Due to the effects on these soil properties, runoff generation was lower in well-developed than in incipient-cyanobacterial biocrusts under both simulated and natural rainfall and on different spatial scales. Runoff yield decreased at coarser spatial scales due to re-infiltration along the hillslope, thus decreasing hydrological connectivity. Soil moisture monitoring at 0.03 m depth revealed higher moisture content and slower soil water loss in plots covered by cyanobacterial biocrusts compared to bare soils. Non-rainfall water inputs were also higher under well-developed cyanobacterial biocrusts than in bare soils. Disturbance of cyanobacterial biocrusts seriously affected the water balance by increasing runoff, decreasing soil moisture and accelerating soil water loss, at the same time that led to a very significant increase in sediment yield. The recovery of biocrust cover after disturbance can be relatively fast, but its growth rate is strongly conditioned by microclimate. The results of this paper show the important influence of cyanobacterial biocrust in modulating the different processes supporting the capacity of these ecosystems to provide key services such as water regulation or erosion control, and also the important impacts of their anthropic disturbance.

The role of the nasal glands in the survival of ducks (Anas platyrhynchos) exposed to hypertonic saline drinking water

1972 ◽  
Vol 50 (5) ◽  
pp. 611-617 ◽  
Author(s):  
E. L. Bradley ◽  
W. N. Holmes
Keyword(s):  
Drinking Water ◽  
Body Weight ◽  
Water Balance ◽  
Hypertonic Saline ◽  
Anas Platyrhynchos ◽  
Active Material ◽  
Plasma Concentrations ◽  
Plasma Osmolality ◽  
The Body ◽  
Nasal Glands

The supraorbital nasal glands were removed from the duck (Anas platyrhynchos) 1 week before experimentation. When sham-operated birds were given hypertonic saline drinking water (282 mM NaCl, 6 mM KCl) for 70 h they maintained their body weights and remained in positive water balance. When the ducks lacking nasal glands were similarly treated they became severely dehydrated, lost body weight at the rate of 5.59 ± 1.1 g/h and showed significant increases in the plasma concentrations of Na+, Cl−, K+, and total osmotically active material. When the glandless birds were given hypertonic saline drinking water, the disparity between the measured plasma osmolality and the osmolality calculated on the basis of the Na+, Cl−, and K+ concentrations in plasma increased two-fold. No such change in disparity between the measured and calculated osmolalities of plasma in the sham-operated birds was observed. Forty-eight hours after their return to a diet containing fresh drinking water, the birds without nasal glands regained some of the body weight they had lost and the plasma electrolyte concentrations were restored towards normal. It is concluded that in the absence of nasal glands, the kidney alone is incapable of maintaining positive water balance in ducks fed hypertonic saline as their only source of drinking water.

Sign in / Sign up

Export Citation Format

Share Document