American White Pelican Soaring Flight Times and Altitudes Relative to Changes in Thermal Depth and Intensity

Shannon, Harlan D.; Young, George S.; Yates, Michael A.; Fuller, Mark R.; Seegar, William S.

doi:10.1650/0010-5422(2002)104[0679:awpsft]2.0.co;2

Cited by 59 publications

(75 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Another soaring-gliding species, the American white pelican (Pelecanus erythrorhynchos), was also found to soar only above a certain threshold of thermal intensity. This species is adapted only for sustained soaring and cannot flap for long periods of time; therefore, the birds did not fly when updraught intensity was below this threshold [13].…”

Section: Discussionmentioning

confidence: 99%

Migration by soaring or flapping: numerical atmospheric simulations reveal that turbulence kinetic energy dictates bee-eater flight mode

et al. 2011

View full text Add to dashboard Cite

Aerial migrants commonly face atmospheric dynamics that may affect their movement and behaviour. Specifically, bird flight mode has been suggested to depend on convective updraught availability and tailwind assistance. However, this has not been tested thus far since both bird tracks and meteorological conditions are difficult to measure in detail throughout extended migratory flyways. Here, we applied, to our knowledge, the first comprehensive numerical atmospheric simulations by mean of the Regional Atmospheric Modeling System (RAMS) to study how meteorological processes affect the flight behaviour of migrating birds. We followed European bee-eaters (Merops apiaster) over southern Israel using radio telemetry and contrasted bird flight mode (flapping, soaring -gliding or mixed flight) against explanatory meteorological variables estimated by RAMS simulations at a spatial grid resolution of 250 Â 250 m 2 . We found that temperature and especially turbulence kinetic energy (TKE) determine bee-eater flight mode, whereas, unexpectedly, no effect of tailwind assistance was found. TKE during soaring -gliding was significantly higher and distinct from TKE during flapping. We propose that applying detailed atmospheric simulations over extended migratory flyways can elucidate the highly dynamic behaviour of air-borne organisms, help predict the abundance and distribution of migrating birds, and aid in mitigating hazardous implications of bird migration.

show abstract

Section: Discussionmentioning

confidence: 99%

Migration by soaring or flapping: numerical atmospheric simulations reveal that turbulence kinetic energy dictates bee-eater flight mode

et al. 2011

View full text Add to dashboard Cite

show abstract

“…Several studies have looked at the relationship of soaring birds to convective and sheer turbulence, using direct observation, and found that use of thermals for soaring varies with species, body size, behavior, time of day, and thermal intensity (6,14,29,30). The turkey vulture's ability to soar effectively in turbulent winds may be enhanced by its dihedral wing profile, which is inherently more stable than that of birds that soar with a horizontal wing profile (31) and may be particularly important in situations in turbulent conditions within the atmospheric boundary layer but close to the ground (32).…”

Section: Discussionmentioning

confidence: 99%

Movement ecology of migration in turkey vultures

Mandel

Bildstein

Bohrer

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

114

143

View full text Add to dashboard Cite

We develop individual-based movement ecology models (MEM) to explore turkey vulture (Cathartes aura) migration decisions at both hourly and daily scales. Vulture movements in 10 migration events were recorded with satellite-reporting GPS sensors, and flight behavior was observed visually, aided by on-the-ground VHF radio-tracking. We used the North American Regional Reanalysis dataset to obtain values for wind speed, turbulent kinetic energy (TKE), and cloud height and used a digital elevation model for a measure of terrain ruggedness. A turkey vulture fitted with a heart-rate logger during 124 h of flight during 38 contiguous days showed only a small increase in mean heart rate as distance traveled per day increased, which suggests that, unlike flapping, soaring flight does not lead to greatly increased metabolic costs. Data from 10 migrations for 724 hourly segments and 152 daily segments showed that vultures depended heavily upon high levels of TKE in the atmospheric boundary layer to increase flight distances and maintain preferred bearings at both hourly and daily scales. We suggest how the MEM can be extended to other spatial and temporal scales of avian migration. Our success in relating model-derived atmospheric variables to migration indicates the potential of using regional reanalysis data, as here, and potentially other regional, higher-resolution, atmospheric models in predicting changing movement patterns of soaring birds under various scenarios of climate and land use change.energetics ͉ flight ͉ meteorology T raditionally, bird migration has been treated separately relative to other movements within an individual's life history (1-2). Although long-distance migration operates on different scales and produces different patterns than those of other movement types in a bird's life cycle, there are also many similarities (cf. ref.3). As in other biotic movements, migration involves the assessment of internal state of the organism, external factors, and past behavior to make decisions about motion and navigation (4).One significant challenge of migration research is measuring the extent to which migratory routes and schedules of individual migrants are influenced by external factors, including wind direction and speed (5-6), food availability and habitat (2), and the behavior of other migrants (1, 7). One important axis of variation among migratory birds is the extent to which environmental factors act as facilitators of, as opposed to barriers to, movement. Determining the effects of environmental factors is particularly important for soaring birds, whose movements rely upon environmental factors such as deflection updrafts and thermal convection as their principle means of propulsion, whereas those using primarily flapping flight are, in principal, not directly dependent on environmental forces for propulsion and lift. Although we recognize that this categorization can be overly simplistic (see, for example, ref. 8) and that other categorizations based on ecological function exist (9-10), the dichoto...

show abstract

“…migration or long-distance dispersal); during these movement, individuals are challenged to traverse long distances with an ensuing need to minimize energetic cost of transport [29], overall time [30], or a weighted combination of these two under risk-avoidance constraints. In contrast, home-range foraging movements are motivated by a need to obtain food within a restricted region, and a time minimization imperative is less likely to be operating than during long-range movements [31]. At this intermediate scale, foraging trips contain different movement phases, which are sequences of steps associated with the fulfilment of a particular set of goals [5].…”

Section: Introductionmentioning

confidence: 99%

Decision-making by a soaring bird: time, energy and risk considerations at different spatio-temporal scales

Harel

Duriez

Spiegel

et al. 2016

Phil. Trans. R. Soc. B

View full text Add to dashboard Cite

One contribution of 17 to a theme issue 'Moving in a moving medium: new perspectives on flight'. Natural selection theory suggests that mobile animals trade off time, energy and risk costs with food, safety and other pay-offs obtained by movement. We examined how birds make movement decisions by integrating aspects of flight biomechanics, movement ecology and behaviour in a hierarchical framework investigating flight track variation across several spatio-temporal scales. Using extensive global positioning system and accelerometer data from Eurasian griffon vultures (Gyps fulvus) in Israel and France, we examined soaring-gliding decision-making by comparing inbound versus outbound flights (to or from a central roost, respectively), and these (and other) homerange foraging movements (up to 300 km) versus long-range movements (longer than 300 km). We found that long-range movements and inbound flights have similar features compared with their counterparts: individuals reduced journey time by performing more efficient soaring -gliding flight, reduced energy expenditure by flapping less and were more risk-prone by gliding more steeply between thermals. Age, breeding status, wind conditions and flight altitude (but not sex) affected time and energy prioritization during flights. We therefore suggest that individuals facing time, energy and risk trade-offs during movements make similar decisions across a broad range of ecological contexts and spatial scales, presumably owing to similarity in the uncertainty about movement outcomes.This article is part of the themed issue 'Moving in a moving medium: new perspectives on flight'.

show abstract

American White Pelican Soaring Flight Times and Altitudes Relative to Changes in Thermal Depth and Intensity

Cited by 59 publications

References 10 publications

Migration by soaring or flapping: numerical atmospheric simulations reveal that turbulence kinetic energy dictates bee-eater flight mode

Migration by soaring or flapping: numerical atmospheric simulations reveal that turbulence kinetic energy dictates bee-eater flight mode

Movement ecology of migration in turkey vultures

Decision-making by a soaring bird: time, energy and risk considerations at different spatio-temporal scales

Contact Info

Product

Resources

About