22
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Flight Modes in Migrating European Bee-Eaters: Heart Rate May Indicate Low Metabolic Rate during Soaring and Gliding

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Background

          Many avian species soar and glide over land. Evidence from large birds ( m b>0.9 kg) suggests that soaring-gliding is considerably cheaper in terms of energy than flapping flight, and costs about two to three times the basal metabolic rate (BMR). Yet, soaring-gliding is considered unfavorable for small birds because migration speed in small birds during soaring-gliding is believed to be lower than that of flapping flight. Nevertheless, several small bird species routinely soar and glide.

          Methodology/Principal Findings

          To estimate the energetic cost of soaring-gliding flight in small birds, we measured heart beat frequencies of free-ranging migrating European bee-eaters ( Merops apiaster, m b∼55 g) using radio telemetry, and established the relationship between heart beat frequency and metabolic rate (by indirect calorimetry) in the laboratory. Heart beat frequency during sustained soaring-gliding was 2.2 to 2.5 times lower than during flapping flight, but similar to, and not significantly different from, that measured in resting birds. We estimated that soaring-gliding metabolic rate of European bee-eaters is about twice their basal metabolic rate (BMR), which is similar to the value estimated in the black-browed albatross Thalassarche (previously Diomedea) melanophrys, m b∼4 kg). We found that soaring-gliding migration speed is not significantly different from flapping migration speed.

          Conclusions/Significance

          We found no evidence that soaring-gliding speed is slower than flapping flight in bee-eaters, contradicting earlier estimates that implied a migration speed penalty for using soaring-gliding rather than flapping flight. Moreover, we suggest that small birds soar and glide during migration, breeding, dispersal, and other stages in their annual cycle because it may entail a low energy cost of transport. We propose that the energy cost of soaring-gliding may be proportional to BMR regardless of bird size, as theoretically deduced by earlier studies.

          Related collections

          Most cited references28

          • Record: found
          • Abstract: found
          • Article: not found

          Migrating songbirds recalibrate their magnetic compass daily from twilight cues.

          Night migratory songbirds can use stars, sun, geomagnetic field, and polarized light for orientation when tested in captivity. We studied the interaction of magnetic, stellar, and twilight orientation cues in free-flying songbirds. We exposed Catharus thrushes to eastward-turned magnetic fields during the twilight period before takeoff and then followed them for up to 1100 kilometers. Instead of heading north, experimental birds flew westward. On subsequent nights, the same individuals migrated northward again. We suggest that birds orient with a magnetic compass calibrated daily from twilight cues. This could explain how birds cross the magnetic equator and deal with declination.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Fast and fuel efficient? Optimal use of wind by flying albatrosses.

            The influence of wind patterns on behaviour and effort of free-ranging male wandering albatrosses (Diomedea exulans) was studied with miniaturized external heart-rate recorders in conjunction with satellite transmitters and activity recorders. Heart rate was used as an instantaneous index of energy expenditure. When cruising with favourable tail or side winds, wandering albatrosses can achieve high flight speeds while expending little more energy than birds resting on land. In contrast, heart rate increases concomitantly with increasing head winds, and flight speeds decrease. Our results show that effort is greatest when albatrosses take off from or land on the water. On a larger scale, we show that in order for birds to have the highest probability of experiencing favourable winds, wandering albatrosses use predictable weather systems to engage in a stereotypical flight pattern of large looping tracks. When heading north, albatrosses fly in anticlockwise loops, and to the south, movements are in a clockwise direction. Thus, the capacity to integrate instantaneous eco-physiological measures with records of large-scale flight and wind patterns allows us to understand better the complex interplay between the evolution of morphological, physiological and behavioural adaptations of albatrosses in the windiest place on earth.
              Bookmark
              • Record: found
              • Abstract: not found
              • Article: not found

              Measuring metabolic rate in the field: the pros and cons of the doubly labelled water and heart rate methods

                Bookmark

                Author and article information

                Contributors
                Role: Editor
                Journal
                PLoS One
                plos
                plosone
                PLoS ONE
                Public Library of Science (San Francisco, USA )
                1932-6203
                2010
                11 November 2010
                : 5
                : 11
                : e13956
                Affiliations
                [1 ]Movement Ecology Laboratory, Department of Evolution, Systematics and Ecology, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
                [2 ]Max Planck Institute for Ornithology, Vogelwarte Radolfzell, Radolfzell, Germany
                [3 ]Department of Biological Sciences, St. Mary's University, San Antonio, Texas, United States of America
                [4 ]Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel
                [5 ]Department of Biology, Konstanz University, Konstanz, Germany
                Roehampton University, United Kingdom
                Author notes

                Conceived and designed the experiments: NS MW MDM BP RN. Performed the experiments: NS MDM. Analyzed the data: NS MDM. Contributed reagents/materials/analysis tools: MW BP RN. Wrote the paper: NS MW MDM BP RN.

                [¤]

                Current address: Department of Integrative Biology, University of California, Berkeley, California, United States of America

                Article
                10-PONE-RA-17893R1
                10.1371/journal.pone.0013956
                2978710
                21085655
                a516d35c-8b36-4a2a-85a5-0a241d22349e
                Sapir et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
                History
                : 13 April 2010
                : 19 October 2010
                Page count
                Pages: 13
                Categories
                Research Article
                Ecology/Behavioral Ecology
                Ecology/Physiological Ecology
                Evolutionary Biology/Animal Behavior
                Evolutionary Biology/Evolutionary Ecology

                Uncategorized
                Uncategorized

                Comments

                Comment on this article