1
|
Bonadonna F, Gagliardo A. Not only pigeons: avian olfactory navigation studied by satellite telemetry. ETHOL ECOL EVOL 2021. [DOI: 10.1080/03949370.2021.1871967] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Francesco Bonadonna
- CEFE-CNRS, University of Montpellier, EPHE, IRD, University Paul Valéry Montpellier 3, Montpellier, France
| | | |
Collapse
|
2
|
Bingman VP, Pemberton ML, Mora CV. Avian forebrain processing of magnetic intensity and inclination: hippocampus, anterior forebrain Wulst and an unexpected double-dissociation. ETHOL ECOL EVOL 2021. [DOI: 10.1080/03949370.2021.1871966] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Verner P. Bingman
- Department of Psychology and J.P. Scott Center for Neuroscience, Mind and Behavior, Bowling Green State University, Bowling Green, Ohio 43403, USA
| | - Merissa L. Pemberton
- Department of Psychology and J.P. Scott Center for Neuroscience, Mind and Behavior, Bowling Green State University, Bowling Green, Ohio 43403, USA
| | - Cordula V. Mora
- Department of Psychology and J.P. Scott Center for Neuroscience, Mind and Behavior, Bowling Green State University, Bowling Green, Ohio 43403, USA
| |
Collapse
|
3
|
Shao Y, Tian HY, Zhang JJ, Kharrati-Koopaee H, Guo X, Zhuang XL, Li ML, Nanaie HA, Dehghani Tafti E, Shojaei B, Reza Namavar M, Sotoudeh N, Oluwakemi Ayoola A, Li JL, Liang B, Esmailizadeh A, Wang S, Wu DD. Genomic and Phenotypic Analyses Reveal Mechanisms Underlying Homing Ability in Pigeon. Mol Biol Evol 2020; 37:134-148. [PMID: 31501895 DOI: 10.1093/molbev/msz208] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The homing pigeon was selectively bred from the domestic pigeon for a homing ability over long distances, a very fascinating but complex behavioral trait. Here, we generate a total of 95 whole genomes from diverse pigeon breeds. Comparing the genomes from the homing pigeon population with those from other breeds identifies candidate positively selected genes, including many genes involved in the central nervous system, particularly spatial learning and memory such as LRP8. Expression profiling reveals many neuronal genes displaying differential expression in the hippocampus, which is the key organ for memory and navigation and exhibits significantly larger size in the homing pigeon. In addition, we uncover a candidate gene GSR (encoding glutathione-disulfide reductase) experiencing positive selection in the homing pigeon. Expression profiling finds that GSR is highly expressed in the wattle and visual pigment cell layer, and displays increased expression levels in the homing pigeon. In vitro, a magnetic field stimulates increases in calcium ion concentration in cells expressing pigeon GSR. These findings support the importance of the hippocampus (functioning in spatial memory and navigation) for homing ability, and the potential involvement of GSR in pigeon magnetoreception.
Collapse
Affiliation(s)
- Yong Shao
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Hang-Yu Tian
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Kunming College of Life Science, University of the Chinese Academy of Sciences, Kunming, China
| | - Jing-Jing Zhang
- Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Department of Hepatobiliary Surgery, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Hamed Kharrati-Koopaee
- Department of Animal Science, Faculty of Agriculture, Shahid Bahonar University of Kerman, Kerman, Iran.,Institute of Biotechnology, School of Agriculture, Shiraz University, Shiraz, Iran
| | - Xing Guo
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, China
| | - Xiao-Lin Zhuang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Kunming College of Life Science, University of the Chinese Academy of Sciences, Kunming, China
| | - Ming-Li Li
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Kunming College of Life Science, University of the Chinese Academy of Sciences, Kunming, China
| | | | - Elahe Dehghani Tafti
- Department of Basic Sciences, Faculty of Veterinary Medicine, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Bahador Shojaei
- Department of Basic Sciences, Faculty of Veterinary Medicine, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Mohammad Reza Namavar
- Clinical Neurology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.,Histomorphometry and Stereology Research Center, Shiraz University of Medical Science, Shiraz, Iran
| | - Narges Sotoudeh
- Clinical Neurology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.,Anatomy Department, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Adeola Oluwakemi Ayoola
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Kunming College of Life Science, University of the Chinese Academy of Sciences, Kunming, China
| | - Jia-Li Li
- Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, China
| | - Bin Liang
- Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, China
| | - Ali Esmailizadeh
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Department of Animal Science, Faculty of Agriculture, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Shu Wang
- School of Basic Medical Sciences, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Dong-Dong Wu
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, China
| |
Collapse
|
4
|
Kheradmand B, Nieh JC. The Role of Landscapes and Landmarks in Bee Navigation: A Review. INSECTS 2019; 10:E342. [PMID: 31614833 PMCID: PMC6835465 DOI: 10.3390/insects10100342] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 10/08/2019] [Accepted: 10/09/2019] [Indexed: 11/16/2022]
Abstract
The ability of animals to explore landmarks in their environment is essential to their fitness. Landmarks are widely recognized to play a key role in navigation by providing information in multiple sensory modalities. However, what is a landmark? We propose that animals use a hierarchy of information based upon its utility and salience when an animal is in a given motivational state. Focusing on honeybees, we suggest that foragers choose landmarks based upon their relative uniqueness, conspicuousness, stability, and context. We also propose that it is useful to distinguish between landmarks that provide sensory input that changes ("near") or does not change ("far") as the receiver uses these landmarks to navigate. However, we recognize that this distinction occurs on a continuum and is not a clear-cut dichotomy. We review the rich literature on landmarks, focusing on recent studies that have illuminated our understanding of the kinds of information that bees use, how they use it, potential mechanisms, and future research directions.
Collapse
Affiliation(s)
- Bahram Kheradmand
- Section of Ecology, Behavior, and Evolution, Division of Biological Sciences, UC San Diego, La Jolla, CA 92093, USA.
| | - James C Nieh
- Section of Ecology, Behavior, and Evolution, Division of Biological Sciences, UC San Diego, La Jolla, CA 92093, USA.
| |
Collapse
|
5
|
Behavioural traits of individual homing pigeons, Columba livia f. domestica, in their homing flights. PLoS One 2018; 13:e0201291. [PMID: 30260962 PMCID: PMC6160002 DOI: 10.1371/journal.pone.0201291] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 07/12/2018] [Indexed: 11/29/2022] Open
Abstract
Homing tracks of two groups of pigeons, Columba livia f. domestica, were analyzed in view of difference between individual birds and correlations between characteristic variables, looking at the initial phase while the pigeons were still at the release site, and the homing phase separately. Individual birds differed significantly in their flying speed during the initial phase, and one pigeon tended to stay longer at the release site than the others. There were no significant differences in steadiness and efficiency, indicating that all pigeons homed equally well. Differences in correlation dimension, a variable reflecting the complexity of the navigational process, reflect differences in the use of navigational information, with one bird apparently using less complex information than others. The flying speed during the initial phase was positively correlated with the flying speed during the homing phase. During the homing phase, the steadiness of flight and the efficiency of homing were closely correlated, and both tended to be positively correlated with the correlation dimension, suggesting that birds that use more complex navigational information home more efficiently.
Collapse
|
6
|
The orientation of homing pigeons (Columba livia f.d.) with and without navigational experience in a two-dimensional environment. PLoS One 2017; 12:e0188483. [PMID: 29176875 PMCID: PMC5703563 DOI: 10.1371/journal.pone.0188483] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Accepted: 11/08/2017] [Indexed: 11/19/2022] Open
Abstract
Homing pigeons are known for their excellent homing ability, and their brains seem to be functionally adapted to homing. It is known that pigeons with navigational experience show a larger hippocampus and also a more lateralised brain than pigeons without navigational experience. So we hypothesized that experience may have an influence also on orientation ability. We examined two groups of pigeons (11 with navigational experience and 17 without) in a standard operant chamber with a touch screen monitor showing a 2-D schematic of a rectangular environment (as “geometric” information) and one uniquely shaped and colored feature in each corner (as “landmark” information). Pigeons were trained first for pecking on one of these features and then we examined their ability to encode geometric and landmark information in four tests by modifying the rectangular environment. All tests were done under binocular and monocular viewing to test hemispheric dominance. The number of pecks was counted for analysis. Results show that generally both groups orientate on the basis of landmarks and the geometry of environment, but landmark information was preferred. Pigeons with navigational experience did not perform better on the tests but showed a better conjunction of the different kinds of information. Significant differences between monocular and binocular viewing were detected particularly in pigeons without navigational experience on two tests with reduced information. Our data suggest that the conjunction of geometric and landmark information might be integrated after processing separately in each hemisphere and that this process is influenced by experience.
Collapse
|
7
|
|
8
|
Safi K, Gagliardo A, Wikelski M, Kranstauber B. How Displaced Migratory Birds Could Use Volatile Atmospheric Compounds to Find Their Migratory Corridor: A Test Using a Particle Dispersion Model. Front Behav Neurosci 2016; 10:175. [PMID: 27799899 PMCID: PMC5065961 DOI: 10.3389/fnbeh.2016.00175] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Accepted: 08/31/2016] [Indexed: 11/23/2022] Open
Abstract
Olfaction represents an important sensory modality for navigation of both homing pigeons and wild birds. Experimental evidence in homing pigeons showed that airborne volatile compounds carried by the winds at the home area are learned in association with wind directions. When displaced, pigeons obtain information on the direction of their displacement using local odors at the release site. Recently, the role of olfactory cues in navigation has been reported also for wild birds during migration. However, the question whether wild birds develop an olfactory navigational map similar to that described in homing pigeons or, alternatively, exploit the distribution of volatile compounds in different manner for reaching the goal is still an open question. Using an interdisciplinary approach, we evaluate the possibilities of reconstructing spatio-temporally explicit aerosol dispersion at large spatial scales using the particle dispersion model FLEXPART. By combining atmospheric information with particle dispersion models, atmospheric scientists predict the dispersion of pollutants for example, after nuclear fallouts or volcanic eruptions or wildfires, or in retrospect reconstruct the origin of emissions such as aerosols. Using simple assumptions, we reconstructed the putative origin of aerosols traveling to the location of migrating birds. We use the model to test whether the putative odor plume could have originated from an important stopover site. If the migrating birds knew this site and the associated plume from previous journeys, the odor could contribute to the reorientation towards the migratory corridor, as suggested for the model scenario in displaced Lesser black-backed gulls migrating from Northern Europe into Africa.
Collapse
Affiliation(s)
- Kamran Safi
- Department of Migration and Immuno-Ecology, Max Planck Institute for OrnithologyRadolfzell, Germany
- Department of Biology, University of KonstanzKonstanz, Germany
| | | | - Martin Wikelski
- Department of Migration and Immuno-Ecology, Max Planck Institute for OrnithologyRadolfzell, Germany
- Department of Biology, University of KonstanzKonstanz, Germany
| | - Bart Kranstauber
- Department of Migration and Immuno-Ecology, Max Planck Institute for OrnithologyRadolfzell, Germany
- Department of Biology, University of KonstanzKonstanz, Germany
| |
Collapse
|
9
|
Embodied Motor Control of Avian Vocal Production. VERTEBRATE SOUND PRODUCTION AND ACOUSTIC COMMUNICATION 2016. [DOI: 10.1007/978-3-319-27721-9_5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
10
|
Shaw J, Boyd A, House M, Woodward R, Mathes F, Cowin G, Saunders M, Baer B. Magnetic particle-mediated magnetoreception. J R Soc Interface 2015; 12:0499. [PMID: 26333810 PMCID: PMC4614459 DOI: 10.1098/rsif.2015.0499] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 08/12/2015] [Indexed: 11/12/2022] Open
Abstract
Behavioural studies underpin the weight of experimental evidence for the existence of a magnetic sense in animals. In contrast, studies aimed at understanding the mechanistic basis of magnetoreception by determining the anatomical location, structure and function of sensory cells have been inconclusive. In this review, studies attempting to demonstrate the existence of a magnetoreceptor based on the principles of the magnetite hypothesis are examined. Specific attention is given to the range of techniques, and main animal model systems that have been used in the search for magnetite particulates. Anatomical location/cell rarity and composition are identified as two key obstacles that must be addressed in order to make progress in locating and characterizing a magnetite-based magnetoreceptor cell. Avenues for further study are suggested, including the need for novel experimental, correlative, multimodal and multidisciplinary approaches. The aim of this review is to inspire new efforts towards understanding the cellular basis of magnetoreception in animals, which will in turn inform a new era of behavioural research based on first principles.
Collapse
Affiliation(s)
- Jeremy Shaw
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Alastair Boyd
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Michael House
- School of Physics, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Robert Woodward
- School of Physics, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Falko Mathes
- School of Earth and Environment, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Gary Cowin
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Martin Saunders
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Boris Baer
- Centre for Integrative Bee Research (CIBER), The University of Western Australia, Perth, Western Australia 6009, Australia
| |
Collapse
|
11
|
Kishkinev DA, Chernetsov NS. Magnetoreception systems in birds: A review of current research. ACTA ACUST UNITED AC 2015. [DOI: 10.1134/s2079086415010041] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
12
|
Postlethwaite CM, Walker MM. A model for navigational errors in complex environmental fields. J Theor Biol 2014; 363:134-44. [PMID: 25149368 DOI: 10.1016/j.jtbi.2014.08.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 08/06/2014] [Accepted: 08/07/2014] [Indexed: 10/24/2022]
Abstract
Many animals are believed to navigate using environmental signals such as light, sound, odours and magnetic fields. However, animals rarely navigate directly to their target location, but instead make a series of navigational errors which are corrected during transit. In previous work, we introduced a model showing that differences between an animal׳s 'cognitive map' of the environmental signals used for navigation and the true nature of these signals caused a systematic pattern in orientation errors when navigation begins. The model successfully predicted the pattern of errors seen in previously collected data from homing pigeons, but underestimated the amplitude of the errors. In this paper, we extend our previous model to include more complicated distortions of the contour lines of the environmental signals. Specifically, we consider the occurrence of critical points in the fields describing the signals. We consider three scenarios and compute orientation errors as parameters are varied in each case. We show that the occurrence of critical points can be associated with large variations in initial orientation errors over a small geographic area. We discuss the implications that these results have on predicting how animals will behave when encountering complex distortions in any environmental signals they use to navigate.
Collapse
Affiliation(s)
- Claire M Postlethwaite
- Department of Mathematics, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
| | - Michael M Walker
- School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
| |
Collapse
|
13
|
Gagliardo A, Bried J, Lambardi P, Luschi P, Wikelski M, Bonadonna F. Oceanic navigation in Cory's shearwaters: evidence for a crucial role of olfactory cues for homing after displacement. ACTA ACUST UNITED AC 2014; 216:2798-805. [PMID: 23842626 DOI: 10.1242/jeb.085738] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Pelagic birds, which wander in the open sea most of the year and often nest on small remote oceanic islands, are able to pinpoint their breeding colony even within an apparently featureless environment, such as the open ocean. The mechanisms underlying their surprising navigational performance are still unknown. In order to investigate the nature of the cues exploited for oceanic navigation, Cory's shearwaters, Calonectris borealis, nesting in the Azores were displaced and released in open ocean at about 800 km from their colony, after being subjected to sensory manipulation. While magnetically disturbed shearwaters showed unaltered navigational performance and behaved similarly to unmanipulated control birds, the shearwaters deprived of their sense of smell were dramatically impaired in orientation and homing. Our data show that seabirds use olfactory cues not only to find their food but also to navigate over vast distances in the ocean.
Collapse
Affiliation(s)
- Anna Gagliardo
- Department of Biology, University of Pisa, Via Volta 6, 56126 Pisa, Italy.
| | | | | | | | | | | |
Collapse
|
14
|
Affiliation(s)
- R. A. Holland
- School of Biological Sciences; Queen's University of Belfast; Belfast UK
| |
Collapse
|
15
|
Mora CV, Acerbi ML, Bingman VP. Conditioned discrimination of magnetic inclination in a spatial-orientation arena task by homing pigeons (Columba livia). J Exp Biol 2014; 217:4123-31. [PMID: 25278470 DOI: 10.1242/jeb.101113] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
It has been well established that homing pigeons are able to use the Earth’s magnetic field to obtain directional information when returning to their loft and that their magnetic compass is based, at least in part, on the perception of magnetic inclination. Magnetic inclination has also been hypothesized in pigeons and other long-distance navigators, such as sea turtles, to play a role providing positional information as part of a map. Here we developed a behavioural paradigm which allows us to condition homing pigeons to discriminate magnetic inclination cues in a spatial-orientation arena task. Six homing pigeons were required to discriminate in a circular arena between feeders located either in a zone with a close to 0º inclination cue or in a zone with a rapidly changing inclination cue (-3º to +85º when approaching the feeder and +85º to -3º when moving away from the feeder) to obtain a food reward. The pigeons consistently performed this task above chance level. Control experiments, during which the coils were turned off or the current was running anti-parallel through the double-wound coils system, confirmed that no alternative cues were used by the birds in the discrimination task. The results show that homing pigeons can be conditioned to discriminate differences in magnetic field inclination, enabling investigation into the peripheral and central neural processing of geomagnetic inclination under controlled laboratory conditions.
Collapse
|
16
|
Detection of magnetic field intensity gradient by homing pigeons (Columba livia) in a novel "virtual magnetic map" conditioning paradigm. PLoS One 2013; 8:e72869. [PMID: 24039812 PMCID: PMC3767695 DOI: 10.1371/journal.pone.0072869] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 07/21/2013] [Indexed: 11/19/2022] Open
Abstract
It has long been thought that birds may use the Earth's magnetic field not only as a compass for direction finding, but that it could also provide spatial information for position determination analogous to a map during navigation. Since magnetic field intensity varies systematically with latitude and theoretically could also provide longitudinal information during position determination, birds using a magnetic map should be able to discriminate magnetic field intensity cues in the laboratory. Here we demonstrate a novel behavioural paradigm requiring homing pigeons to identify the direction of a magnetic field intensity gradient in a “virtual magnetic map” during a spatial conditioning task. Not only were the pigeons able to detect the direction of the intensity gradient, but they were even able to discriminate upward versus downward movement on the gradient by differentiating between increasing and decreasing intensity values. Furthermore, the pigeons typically spent more than half of the 15 second sampling period in front of the feeder associated with the rewarded gradient direction indicating that they required only several seconds to make the correct choice. Our results therefore demonstrate for the first time that pigeons not only can detect the presence and absence of magnetic anomalies, as previous studies had shown, but are even able to detect and respond to changes in magnetic field intensity alone, including the directionality of such changes, in the context of spatial orientation within an experimental arena. This opens up the possibility for systematic and detailed studies of how pigeons could use magnetic intensity cues during position determination as well as how intensity is perceived and where it is processed in the brain.
Collapse
|
17
|
Kishkinev D, Chernetsov N, Heyers D, Mouritsen H. Migratory Reed Warblers Need Intact Trigeminal Nerves to Correct for a 1,000 km Eastward Displacement. PLoS One 2013; 8:e65847. [PMID: 23840374 PMCID: PMC3694148 DOI: 10.1371/journal.pone.0065847] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 05/04/2013] [Indexed: 11/19/2022] Open
Abstract
Several studies have shown that experienced night-migratory songbirds can determine their position, but it has remained a mystery which cues and sensory mechanisms they use, in particular, those used to determine longitude (east–west position). One potential solution would be to use a magnetic map or signpost mechanism like the one documented in sea turtles. Night-migratory songbirds have a magnetic compass in their eyes and a second magnetic sense with unknown biological function involving the ophthalmic branch of the trigeminal nerve (V1). Could V1 be involved in determining east–west position? We displaced 57 Eurasian reed warblers (Acrocephalus scirpaceus) with or without sectioned V1. Sham operated birds corrected their orientation towards the breeding area after displacement like the untreated controls did. In contrast, V1-sectioned birds did not correct for the displacement. They oriented in the same direction after the displacement as they had done at the capture site. Thus, an intact ophthalmic branch of the trigeminal nerve is necessary for detecting the 1,000 km eastward displacement in this night-migratory songbird. Our results suggest that V1 carries map-related information used in a large-scale map or signpost sense that the reed warblers needed to determine their approximate geographical position and/or an east–west coordinate.
Collapse
Affiliation(s)
- Dmitry Kishkinev
- Arbeitsgruppe “Neurosensorik/Animal Navigation”, Institut für Biologie und Umweltwissenschaften & Research Centre for Neurosensory Sciences, University of Oldenburg, Oldenburg, Germany
- * E-mail:
| | - Nikita Chernetsov
- Biological Station Rybachy, Zoological Institute of Russian Academy of Sciences, Rybachy, Kaliningrad Region, Russia
| | - Dominik Heyers
- Arbeitsgruppe “Neurosensorik/Animal Navigation”, Institut für Biologie und Umweltwissenschaften & Research Centre for Neurosensory Sciences, University of Oldenburg, Oldenburg, Germany
| | - Henrik Mouritsen
- Arbeitsgruppe “Neurosensorik/Animal Navigation”, Institut für Biologie und Umweltwissenschaften & Research Centre for Neurosensory Sciences, University of Oldenburg, Oldenburg, Germany
| |
Collapse
|
18
|
Abstract
Summary
Forty years ago, Papi and colleagues discovered that anosmic pigeons cannot find their way home when released at unfamiliar locations. They explained this phenomenon by developing the olfactory navigation hypothesis: pigeons at the home loft learn the odours carried by the winds in association with wind direction; once at the release site, they determine the direction of displacement on the basis of the odours perceived locally and orient homeward. In addition to the old classical experiments, new GPS tracking data and observations on the activation of the olfactory system in displaced pigeons have provided further evidence for the specific role of olfactory cues in pigeon navigation. Although it is not known which odours the birds might rely on for navigation, it has been shown that volatile organic compounds in the atmosphere are distributed as fairly stable gradients to allow environmental odour-based navigation. The investigation of the potential role of olfactory cues for navigation in wild birds is still at an early stage; however, the evidence collected so far suggests that olfactory navigation might be a widespread mechanism in avian species.
Collapse
Affiliation(s)
- Anna Gagliardo
- Department of Biology, University of Pisa, Via A. Volta 6, I-56126 Pisa, Italy
| |
Collapse
|
19
|
Holland RA, Helm B. A strong magnetic pulse affects the precision of departure direction of naturally migrating adult but not juvenile birds. J R Soc Interface 2013; 10:20121047. [PMID: 23389901 DOI: 10.1098/rsif.2012.1047] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The mechanisms by which migratory birds achieve their often spectacular navigational performance are still largely unclear, but perception of cues from the Earth's magnetic field is thought to play a role. Birds that possess migratory experience can use map-based navigation, which may involve a receptor that uses ferrimagnetic material for detecting gradients in the magnetic field. Such a mechanism can be experimentally disrupted by applying a strong magnetic pulse that re-magnetizes ferrimagnetic materials. In captivity, this treatment indeed affected bearings of adult but not of naive juvenile birds. However, field studies, which expose birds to various navigational cues, yielded mixed results. Supportive studies were difficult to interpret because they were conducted in spring when all age groups navigate back to breeding areas. The present study, therefore, applied a magnetic pulse treatment in autumn to naturally migrating, radio-tagged European robins. We found that, although overall bearings were seasonally correct, orientation of adult but not juvenile robins was compromised by a pulse. Pulsed adults that departed within 10 days of treatment failed to show significant orientation and deviated more from mean migration direction than adult controls and juveniles. Thus, our data give field-based support for a possible ferrimagnetic map-sense during bird migration.
Collapse
Affiliation(s)
- Richard A Holland
- Department for Migration and Immune-ecology, Max Planck Institute for Ornithology, Schlossallee 2, Radolfzell 78315, Germany.
| | | |
Collapse
|
20
|
Holland R, Filannino C, Gagliardo A. A magnetic pulse does not affect homing pigeon navigation: a GPS tracking experiment. J Exp Biol 2013; 216:2192-200. [DOI: 10.1242/jeb.083543] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Summary
The cues by which homing pigeons are able to return to a home loft after displacement to unfamiliar release sites remain debated. A number of experiments in which migratory birds have been treated with a magnetic pulse have produced a disruption in their orientation, which argues that a ferrimagnetic sense is used for navigation in birds. One previous experiment has also indicated an effect of magnetic pulses on homing pigeon navigation, although with inconsistent results. Previous studies have shown that some magnetic-related information is transmitted by the trigeminal nerve to the brain in some bird species including the homing pigeon. The function of this information is still unclear. It has been suggested that this information is important for navigation. Previous studies with trigeminal nerve lesioned pigeons have clearly shown that the lack of trigeminally mediated information, even if magnetic, is not crucial for homing performance in homing pigeons. However, this result does not completely exclude the possibility that other ferrimagnetic receptors in the homing pigeon play role in navigation. Additionally, recent studies on homing pigeons suggested the existence of a ferrimagnetic sense in a novel location presumably located in the inner ear (lagena). In the current study, we tested whether any ferrimagnetic magnetoreceptors, irrespective of their location in the bird's head, are involved in pigeons' homing. To do this, we treated homing pigeons with a strong magnetic pulse before release, tracked birds with GPS-loggers and analyzed whether this treatment affected homing performance. In the single previous magnetic pulse experiment on homing pigeons only initial orientation at a release site was considered and the results were inconsistent.We observed no effect of the magnetic pulse at any of the sites used, either in initial orientation, homing performance, tortuosity or track efficiency, which does not support a role for the ferrimagnetic sense in homing pigeon navigation, at least not in this geographic area, where magnetic field variations are in the region of 200 nT intensity and 0.8° inclination.
Collapse
|
21
|
O'Neill P. Magnetoreception and baroreception in birds. Dev Growth Differ 2012; 55:188-97. [DOI: 10.1111/dgd.12025] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 11/01/2012] [Accepted: 11/01/2012] [Indexed: 11/28/2022]
Affiliation(s)
- Paul O'Neill
- Laboratory for Sensory Development; RIKEN Center for Developmental Biology; 2-2-3 Minatojima-Minamimachi, Chuo-ku; Kobe; 650-0047; Japan
| |
Collapse
|
22
|
Mora CV, Walker MM. Consistent effect of an attached magnet on the initial orientation of homing pigeons, Columba livia. Anim Behav 2012. [DOI: 10.1016/j.anbehav.2012.05.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
23
|
From chemotaxis to the cognitive map: the function of olfaction. Proc Natl Acad Sci U S A 2012; 109 Suppl 1:10693-700. [PMID: 22723365 DOI: 10.1073/pnas.1201880109] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A paradox of vertebrate brain evolution is the unexplained variability in the size of the olfactory bulb (OB), in contrast to other brain regions, which scale predictably with brain size. Such variability appears to be the result of selection for olfactory function, yet there is no obvious concordance that would predict the causal relationship between OB size and behavior. This discordance may derive from assuming the primary function of olfaction is odorant discrimination and acuity. If instead the primary function of olfaction is navigation, i.e., predicting odorant distributions in time and space, variability in absolute OB size could be ascribed and explained by variability in navigational demand. This olfactory spatial hypothesis offers a single functional explanation to account for patterns of olfactory system scaling in vertebrates, the primacy of olfaction in spatial navigation, even in visual specialists, and proposes an evolutionary scenario to account for the convergence in olfactory structure and function across protostomes and deuterostomes. In addition, the unique percepts of olfaction may organize odorant information in a parallel map structure. This could have served as a scaffold for the evolution of the parallel map structure of the mammalian hippocampus, and possibly the arthropod mushroom body, and offers an explanation for similar flexible spatial navigation strategies in arthropods and vertebrates.
Collapse
|
24
|
Mouritsen H, Hore PJ. The magnetic retina: light-dependent and trigeminal magnetoreception in migratory birds. Curr Opin Neurobiol 2012; 22:343-52. [DOI: 10.1016/j.conb.2012.01.005] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Revised: 01/03/2012] [Accepted: 01/17/2012] [Indexed: 10/28/2022]
|
25
|
Guilford T, Åkesson S, Gagliardo A, Holland RA, Mouritsen H, Muheim R, Wiltschko R, Wiltschko W, Bingman VP. Migratory navigation in birds: new opportunities in an era of fast-developing tracking technology. ACTA ACUST UNITED AC 2012; 214:3705-12. [PMID: 22031734 DOI: 10.1242/jeb.051292] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Birds have remained the dominant model for studying the mechanisms of animal navigation for decades, with much of what has been discovered coming from laboratory studies or model systems. The miniaturisation of tracking technology in recent years now promises opportunities for studying navigation during migration itself (migratory navigation) on an unprecedented scale. Even if migration tracking studies are principally being designed for other purposes, we argue that attention to salient environmental variables during the design or analysis of a study may enable a host of navigational questions to be addressed, greatly enriching the field. We explore candidate variables in the form of a series of contrasts (e.g. land vs ocean or night vs day migration), which may vary naturally between migratory species, populations or even within the life span of a migrating individual. We discuss how these contrasts might help address questions of sensory mechanisms, spatiotemporal representational strategies and adaptive variation in navigational ability. We suggest that this comparative approach may help enrich our knowledge about the natural history of migratory navigation in birds.
Collapse
Affiliation(s)
- Tim Guilford
- Department of Zoology, South Parks Road, Oxford OX1 3PS, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Del Seppia C, Mencacci R, Luschi P, Varanini M, Ghione S. Differential magnetic field effects on heart rate and nociception in anosmic pigeons. Bioelectromagnetics 2011; 33:309-19. [PMID: 21953246 DOI: 10.1002/bem.20708] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Accepted: 09/01/2011] [Indexed: 11/09/2022]
Abstract
Several studies have shown that exposure to altered magnetic fields affects nociception by suppressing stress-induced hypoalgesia, and that this effect is reduced or abolished if the treatment is performed in the absence of light. This raises the question as to whether other sources of sensory stimuli may also modulate these magnetic effects. We investigated the possible role of olfaction in the magnetically induced effects on sensitivity to nociceptive stimuli and heart rate (HR) in restraint-stressed homing pigeons exposed to an Earth-strength, irregularly varying (<1 Hz) magnetic field. The magnetic treatment decreased the nociceptive threshold in normally smelling birds and an opposite effect was observed in birds made anosmic by nostril plugging. Conversely, no differential effect of olfactory deprivation was observed on HR, which was reduced by the magnetic treatment both in smelling and anosmic pigeons. The findings highlight an important role of olfactory environmental information in the mediation of magnetic effects on nociception, although the data cannot be interpreted unambiguously because of the lack of an additional control group of olfactory-deprived, non-magnetically exposed pigeons. The differential effects on a pigeon's sensitivity to nociceptive stimulus and HR additionally indicate that the magnetic stimuli affect nociception and the cardiovascular system in different ways.
Collapse
Affiliation(s)
- Cristina Del Seppia
- Institute of Clinical Physiology, National Council of Research, Pisa, Italy.
| | | | | | | | | |
Collapse
|
27
|
Patzke N, Manns M, Güntürkün O. Telencephalic organization of the olfactory system in homing pigeons (Columba livia). Neuroscience 2011; 194:53-61. [PMID: 21846495 DOI: 10.1016/j.neuroscience.2011.08.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 07/26/2011] [Accepted: 08/01/2011] [Indexed: 10/17/2022]
Abstract
Pigeons use olfactory cues to navigate over unfamiliar areas, and any impairment of the olfactory system generates remarkable reduction of homing performance. Lesion and deprivation studies suggest a critical involvement of the right nostril and thus, the right olfactory bulb (OB) and the left piriform cortex (CPi) for initial orientation. This functional pattern suggests that OB and CPi are asymmetrically connected with a stronger projection from the right OB to the left CPi. However, the structural organization of the olfactory system is not unequivocally clarified yet. Thus, we re-analyzed the system by antero- and retrograde tract tracing with biotinylated dextran amine and choleratoxin subunit B, and we especially evaluated quantitative differences in the number of cells in the OB innervating the left and right CPi. Our anterograde tracing data verified a strong bilateral input to the CPi, and the prepiriform cortex (CPP), as well as small projections to the ipsilateral medial septum and the dorsolateral corticoid area and the nucleus taeniae of the amygdala in both hemispheres. Apart from the bilateral bulbar afferents, CPi in turn receives unequivocal input from the ipsilateral CPP, hyperpallium densocellulare, dorsal arcopallium, and from a cluster of cells located within the frontolateral nidopallium. Thus, an indirect connection between OB and CPi is only mediated by the CPP. For quantitative analysis of bulbar input to the CPi, we counted the number of ipsi- and contralaterally projecting neurons located in the OB after injections into the left or right CPi. Retrogradely labeled cells were found bilaterally in the OB with a higher number of ipsilaterally located cells. The bilaterality index did not differ after left- or right-sided CPi injections indicating that the functional lateralization of the olfactory system is not simply based on differences in the number of projecting axons of the major processing stream.
Collapse
Affiliation(s)
- N Patzke
- Biopsychology, Faculty of Psychology, Institute of Cognitive Neuroscience, Ruhr-University Bochum, Universitätsstr 150, 44780 Bochum, Germany.
| | | | | |
Collapse
|
28
|
Gagliardo A, Ioalè P, Filannino C, Wikelski M. Homing pigeons only navigate in air with intact environmental odours: a test of the olfactory activation hypothesis with GPS data loggers. PLoS One 2011; 6:e22385. [PMID: 21857925 PMCID: PMC3152288 DOI: 10.1371/journal.pone.0022385] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2011] [Accepted: 06/20/2011] [Indexed: 11/22/2022] Open
Abstract
A large body of evidence has shown that anosmic pigeons are impaired in their navigation. However, the role of odours in navigation is still subject to debate. While according to the olfactory navigation hypothesis homing pigeons possess a navigational map based on the distribution of environmental odours, the olfactory activation hypothesis proposes that odour perception is only needed to activate a navigational mechanism based on cues of another nature. Here we tested experimentally whether the perception of artificial odours is sufficient to allow pigeons to navigate, as expected from the olfactory activation hypothesis. We transported three groups of pigeons in air-tight containers to release sites 53 and 61 km from home in three different olfactory conditions. The Control group received natural environmental air; both the Pure Air and the Artificial Odour groups received pure air filtered through an active charcoal filter. Only the Artificial Odour group received additional puffs of artificial odours until release. We then released pigeons while recording their tracks with 1 Hz GPS data loggers. We also followed non-homing pigeons using an aerial data readout to a Cessna plane, allowing, for the first time, the tracking of non-homing homing pigeons. Within the first hour after release, the pigeons in both the Artificial Odour and the Pure Air group (receiving no environmental odours) showed impaired navigational performances at each release site. Our data provide evidence against an activation role of odours in navigation, and document that pigeons only navigate well when they perceive environmental odours.
Collapse
|
29
|
Rastogi A, Kumari Y, Rani S, Kumar V. Phase inversion of neural activity in the olfactory and visual systems of a night-migratory bird during migration. Eur J Neurosci 2011; 34:99-109. [DOI: 10.1111/j.1460-9568.2011.07737.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
30
|
Postlethwaite CM, Walker MM. A geometric model for initial orientation errors in pigeon navigation. J Theor Biol 2011; 269:273-9. [PMID: 21055408 DOI: 10.1016/j.jtbi.2010.10.036] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Revised: 10/27/2010] [Accepted: 10/27/2010] [Indexed: 11/18/2022]
Affiliation(s)
- Claire M Postlethwaite
- Department of Mathematics, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
| | | |
Collapse
|
31
|
Holland RA. Differential effects of magnetic pulses on the orientation of naturally migrating birds. J R Soc Interface 2010; 7:1617-25. [PMID: 20453067 PMCID: PMC2988258 DOI: 10.1098/rsif.2010.0159] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Accepted: 04/16/2010] [Indexed: 11/12/2022] Open
Abstract
In migratory passerine birds, strong magnetic pulses are thought to be diagnostic of the remagnetization of iron minerals in a putative sensory system contained in the beak. Previous evidence suggests that while such a magnetic pulse affects the orientation of migratory birds in orientation cages, no effect was present when pulse-treated birds were tested in natural migration. Here we show that two migrating passerine birds treated with a strong magnetic pulse, designed to alter the magnetic sense, migrated in a direction that differed significantly from that of controls when tested in natural conditions. The orientation of treated birds was different depending on the alignment of the pulse with respect to the magnetic field. These results can aid in advancing understanding of how the putative iron-mineral-based receptors found in birds' beaks may be used to detect and signal the intensity and/or direction of the Earth's magnetic field.
Collapse
Affiliation(s)
- Richard A Holland
- Department of Migration and Immunoecology, Max Planck Institute for Ornithology, Radolfzell, Germany.
| |
Collapse
|
32
|
Magnetic field changes activate the trigeminal brainstem complex in a migratory bird. Proc Natl Acad Sci U S A 2010; 107:9394-9. [PMID: 20439705 DOI: 10.1073/pnas.0907068107] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The upper beak of birds, which contains putative magnetosensory ferro-magnetic structures, is innervated by the ophthalmic branch of the trigeminal nerve (V1). However, because of the absence of replicable neurobiological evidence, a general acceptance of the involvement of the trigeminal nerve in magnetoreception is lacking in birds. Using an antibody to ZENK protein to indicate neuronal activation, we here document reliable magnetic activation of neurons in and near the principal (PrV) and spinal tract (SpV) nuclei of the trigeminal brainstem complex, which represent the two brain regions known to receive primary input from the trigeminal nerve. Significantly more neurons were activated in PrV and in medial SpV when European robins (Erithacus rubecula) experienced a magnetic field changing every 30 seconds for a period of 3 h (CMF) than when robins experienced a compensated, zero magnetic field condition (ZMF). No such differences in numbers of activated neurons were found in comparison structures. Under CMF conditions, sectioning of V1 significantly reduced the number of activated neurons in and near PrV and medial SpV, but not in lateral SpV or in the optic tectum. Tract tracing of V1 showed spatial proximity and regional overlap of V1 nerve endings and ZENK-positive (activated) neurons in SpV, and partly in PrV, under CMF conditions. Together, these results suggest that magnetic field changes activate neurons in and near the trigeminal brainstem complex and that V1 is necessary for this activation. We therefore suggest that V1 transmits magnetic information to the brain in this migratory passerine bird.
Collapse
|
33
|
A nocturnal mammal, the greater mouse-eared bat, calibrates a magnetic compass by the sun. Proc Natl Acad Sci U S A 2010; 107:6941-5. [PMID: 20351296 DOI: 10.1073/pnas.0912477107] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Recent evidence suggests that bats can detect the geomagnetic field, but the way in which this is used by them for navigation to a home roost remains unresolved. The geomagnetic field may be used by animals both to indicate direction and to locate position. In birds, directional information appears to be derived from an interaction of the magnetic field with either the sun or the stars, with some evidence suggesting that sunset/sunrise provides the primary directional reference by which a magnetic compass is calibrated daily. We demonstrate that homing greater mouse-eared bats (Myotis myotis) calibrate a magnetic compass with sunset cues by testing their homing response after exposure to an altered magnetic field at and after sunset. Magnetic manipulation at sunset resulted in a counterclockwise shift in orientation compared with controls, consistent with sunset calibration of the magnetic field, whereas magnetic manipulation after sunset resulted in no change in orientation. Unlike in birds, however, the pattern of polarization was not necessary for the calibration. For animals that occupy ecological niches where the sunset is rarely observed, this is a surprising finding. Yet it may indicate the primacy of the sun as an absolute geographical reference not only for birds but also within other vertebrate taxa.
Collapse
|
34
|
Thorup K, Holland RA. The bird GPS - long-range navigation in migrants. ACTA ACUST UNITED AC 2010; 212:3597-604. [PMID: 19880719 DOI: 10.1242/jeb.021238] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Nowadays few people consider finding their way in unfamiliar areas a problem as a GPS (Global Positioning System) combined with some simple map software can easily tell you how to get from A to B. Although this opportunity has only become available during the last decade, recent experiments show that long-distance migrating animals had already solved this problem. Even after displacement over thousands of kilometres to previously unknown areas, experienced but not first time migrant birds quickly adjust their course toward their destination, proving the existence of an experience-based GPS in these birds. Determining latitude is a relatively simple task, even for humans, whereas longitude poses much larger problems. Birds and other animals however have found a way to achieve this, although we do not yet know how. Possible ways of determining longitude includes using celestial cues in combination with an internal clock, geomagnetic cues such as magnetic intensity or perhaps even olfactory cues. Presently, there is not enough evidence to rule out any of these, and years of studying birds in a laboratory setting have yielded partly contradictory results. We suggest that a concerted effort, where the study of animals in a natural setting goes hand-in-hand with lab-based study, may be necessary to fully understand the mechanism underlying the long-distance navigation system of birds. As such, researchers must remain receptive to alternative interpretations and bear in mind that animal navigation may not necessarily be similar to the human system, and that we know from many years of investigation of long-distance navigation in birds that at least some birds do have a GPS - but we are uncertain how it works.
Collapse
Affiliation(s)
- Kasper Thorup
- Zoological Museum, University of Copenhagen, Denmark.
| | | |
Collapse
|
35
|
Cadiou H, McNaughton PA. Avian magnetite-based magnetoreception: a physiologist's perspective. J R Soc Interface 2010; 7 Suppl 2:S193-205. [PMID: 20106875 DOI: 10.1098/rsif.2009.0423.focus] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
It is now well established that animals use the Earth's magnetic field to perform long-distance migration and other navigational tasks. However, the transduction mechanisms that allow the conversion of magnetic field variations into an electric signal by specialized sensory cells remain largely unknown. Among the species that have been shown to sense Earth-strength magnetic fields, birds have been a model of choice since behavioural tests show that their direction-finding abilities are strongly influenced by magnetic fields. Magnetite, a ferromagnetic mineral, has been found in a wide range of organisms, from bacteria to vertebrates. In birds, both superparamagnetic (SPM) and single-domain magnetite have been found to be associated with the trigeminal nerve. Electrophysiological recordings from cells in the trigeminal ganglion have shown an increase in action potential firing in response to magnetic field changes. More recently, histological evidence has demonstrated the presence of SPM magnetite in the subcutis of the pigeon's upper beak. The aims of the present review are to review the evidence for a magnetite-based mechanism in birds and to introduce physiological concepts in order to refine the proposed models.
Collapse
Affiliation(s)
- Hervé Cadiou
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK.
| | | |
Collapse
|
36
|
Zapka M, Heyers D, Hein CM, Engels S, Schneider NL, Hans J, Weiler S, Dreyer D, Kishkinev D, Wild JM, Mouritsen H. Visual but not trigeminal mediation of magnetic compass information in a migratory bird. Nature 2009; 461:1274-7. [PMID: 19865170 DOI: 10.1038/nature08528] [Citation(s) in RCA: 170] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Accepted: 09/23/2009] [Indexed: 11/09/2022]
Abstract
Magnetic compass information has a key role in bird orientation, but the physiological mechanisms enabling birds to sense the Earth's magnetic field remain one of the unresolved mysteries in biology. Two biophysical mechanisms have become established as the most promising magnetodetection candidates. The iron-mineral-based hypothesis suggests that magnetic information is detected by magnetoreceptors in the upper beak and transmitted through the ophthalmic branch of the trigeminal nerve to the brain. The light-dependent hypothesis suggests that magnetic field direction is sensed by radical pair-forming photopigments in the eyes and that this visual signal is processed in cluster N, a specialized, night-time active, light-processing forebrain region. Here we report that European robins with bilateral lesions of cluster N are unable to show oriented magnetic-compass-guided behaviour but are able to perform sun compass and star compass orientation behaviour. In contrast, bilateral section of the ophthalmic branch of the trigeminal nerve in European robins did not influence the birds' ability to use their magnetic compass for orientation. These data show that cluster N is required for magnetic compass orientation in this species and indicate that it may be specifically involved in processing of magnetic compass information. Furthermore, the data strongly suggest that a vision-mediated mechanism underlies the magnetic compass in this migratory songbird, and that the putative iron-mineral-based receptors in the upper beak connected to the brain by the trigeminal nerve are neither necessary nor sufficient for magnetic compass orientation in European robins.
Collapse
Affiliation(s)
- Manuela Zapka
- AG Neurosensorik/Animal Navigation, IBU, University of Oldenburg, D-26111 Oldenburg, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Gagliardo A, Ioalè P, Savini M, Wild M. Navigational abilities of adult and experienced homing pigeons deprived of olfactory or trigeminally mediated magnetic information. ACTA ACUST UNITED AC 2009; 212:3119-24. [PMID: 19749104 DOI: 10.1242/jeb.031864] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Anatomical evidence and conditioning experiments have suggested that magnetoreceptors innervated by the ophthalmic branch of the trigeminal nerve are located in the upper beak of homing pigeons. Following these findings it has been proposed that the trigeminally-mediated magnetorececeptors are able to detect magnetic field intensity, which might be useful for a position finding mechanism for pigeons homing from unfamiliar locations. Recent data have shown that, in inexperienced pigeons, section of the ophthalmic branch of the trigeminal nerve does not impair navigational abilities. Similarly, no impairment was observed if the trigeminal section was performed on young pigeons, before they have had the opportunity to learn a navigational map. By contrast, section of the olfactory nerve either in adult inexperienced pigeons or in young birds before map learning, disrupted their homing performance. Nevertheless, because a magnetic map mechanism requires training flights for learning the magnetic gradient of the territory around the loft, the question remains as to whether the navigational performance of adult experienced pigeons can be affected by lack of magnetic information. To answer this question we extensively group-trained adult pigeons and then surgically deprived them of either olfactory or trigeminally mediated magnetic information, prior to testing their navigational abilities. The birds deprived of trigeminally mediated magnetic information displayed similar navigational abilities as intact control pigeons, whereas the olfactory-deprived pigeons were dramatically impaired in homing. Our data show that even in trained adult pigeons, olfactory cues are needed for homing from unfamiliar locations and that the lack of magnetic information does not affect navigational abilities of experienced adult homing pigeons.
Collapse
|
38
|
Holland RA, Thorup K, Gagliardo A, Bisson IA, Knecht E, Mizrahi D, Wikelski M. Testing the role of sensory systems in the migratory heading of a songbird. J Exp Biol 2009; 212:4065-71. [DOI: 10.1242/jeb.034504] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARYThe identification of the sensory cues and mechanisms by which migratory birds are able to reach the same breeding and wintering grounds year after year has eluded biologists despite more than 50 years of intensive study. While a number of environmental cues have been proposed to play a role in the navigation of birds, arguments still persist about which cues are essential for the experience based navigation shown by adult migrants. To date, few studies have tested the sensory basis of navigational cues used during actual migration in the wild: mainly laboratory based studies or homing during the non-migratory season have been used to investigate this behaviour. Here we tested the role of olfactory and magnetic cues in the migration of the catbird (Dumetella carolinensis) by radio tracking the migration of birds with sensory manipulations during their actual migratory flights. Our data suggest that adult birds treated with zinc sulphate to produce anosmia were unable to show the same orientation as control adults, and instead reverted to a direction similar to that shown by juveniles making their first migration. The magnetic manipulation had no effect on the orientation of either adults or juveniles. These results allow us to propose that the olfactory sense may play a role in experience based migration in adult catbirds. While the olfactory sense has been shown to play a role in the homing of pigeons and other birds, this is the first time it has been implicated in migratory orientation.
Collapse
Affiliation(s)
- R. A. Holland
- IICB, University of Leeds, Leeds, LS2 9JT, UK
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
| | - K. Thorup
- Zoological Museum, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark
| | - A. Gagliardo
- Department of Biology, University of Pisa, Via A. Volta 6, I-56126 Pisa, Italy
| | - I. A. Bisson
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
| | - E. Knecht
- Alterra, Center for Ecosystem Studies, PO Box 47, 6700 AA Wageningen, The Netherlands
| | - D. Mizrahi
- New Jersey Audubon Society, Cape May Bird Observatory Centre for Research and Education, Cape May Court House, NJ 08210, USA
| | - M. Wikelski
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
- Max Planck Institute for Ornithology, Department for Migration and Immuno-ecology, Schlossallee 2, Radolfzell 78315, Germany
| |
Collapse
|
39
|
Learning of magnetic compass directions in pigeons. Anim Cogn 2009; 13:443-51. [PMID: 19937359 DOI: 10.1007/s10071-009-0294-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2009] [Revised: 11/04/2009] [Accepted: 11/05/2009] [Indexed: 10/20/2022]
Abstract
A proof of magnetic compass learning by pigeons under laboratory conditions has been attempted for decades, but all experiments have failed so far. The aim of the present study was to test whether pigeons can learn magnetic compass directions in an operant chamber if magnetic cues are presented as true spatial cues. Experimental sessions were carried out in the local geomagnetic field and in magnetic fields with matched total intensity and inclination, but different directions generated with Helmholtz-coils. Birds demonstrated successful learning with a performance level comparable to that in learning studies with magnetic anomalies. In addition, we compared the data from magnetic learning in the laboratory with performance from homing experiments in the field. The birds that were more successful in the learning experiment had vanishing bearings farther away from the home direction than the group mean at unfamiliar, but not at familiar sites. This might suggest that better learners explore unknown locations in a different way. Our findings represent the first evidence for operant magnetic compass learning in pigeons and also provide a link between behavioural data from the field and the laboratory.
Collapse
|
40
|
Gagliardo A, Ioalè P, Savini M, Wild JM. Olfactory navigation in homing pigeons: the last challenge. Ann N Y Acad Sci 2009; 1170:434-7. [PMID: 19686172 DOI: 10.1111/j.1749-6632.2009.03886.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The olfactory navigation hypothesis of pigeon homing was recently challenged by the discovery in the upper beak of putative magnetoreceptors innervated by the ophthalmic branch of the trigeminal nerve. To assess whether the nature of the cues used for navigation is determined by the kind of stimuli to which the birds are preferentially exposed during development, we tested the navigational performance of pigeons subjected when young to section of either the ophthalmic branch of the trigeminal nerve (V1) or the olfactory nerve and then subjected to training flights after the surgery. Section of V1 had no effect on homing performance, but olfactory cues are needed for development of the navigational map.
Collapse
|
41
|
Abstract
Taste is a chemical sense that aids in the detection of nutrients and guides food choice. A limited number of primary qualities comprise taste. Accumulating evidence has raised a question about whether fat should be among them. Most evidence indicates triacylglycerol is not an effective taste stimulus, though it clearly contributes sensory properties to foods by carrying flavor compounds and altering texture. However, there is increasing anatomical, electrophysiological, animal behavior, imaging, metabolic, and psychophysical evidence that free fatty acids are detectable when non-taste cues are minimized. Free fatty acids varying in saturation and chain length are detectable, suggesting the presence of multiple transduction mechanisms and/or a nonspecific mechanism in the oral cavity. However, confirmation of "fatty" as a taste primary will require additional studies that verify these observations are taste specific. Oral exposure to free fatty acids likely serves as a warning signal to discourage intake and influences lipid metabolism.
Collapse
|
42
|
Mora CV, Walker MM. Do release-site biases reflect response to the Earth's magnetic field during position determination by homing pigeons? Proc Biol Sci 2009; 276:3295-302. [PMID: 19556255 DOI: 10.1098/rspb.2009.0872] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
How homing pigeons (Columba livia) return to their loft from distant, unfamiliar sites has long been a mystery. At many release sites, untreated birds consistently vanish from view in a direction different from the home direction, a phenomenon called the release-site bias. These deviations in flight direction have been implicated in the position determination (or map) step of navigation because they may reflect local distortions in information about location that the birds obtain from the geophysical environment at the release site. Here, we performed a post hoc analysis of the relationship between vanishing bearings and local variations in magnetic intensity using previously published datasets for pigeons homing to lofts in Germany. Vanishing bearings of both experienced and naïve birds were strongly associated with magnetic intensity variations at release sites, with 90 per cent of bearings lying within +/-29 degrees of the magnetic intensity slope or contour direction. Our results (i) demonstrate that pigeons respond in an orderly manner to the local structure of the magnetic field at release sites, (ii) provide a mechanism for the occurrence of release-site biases and (iii) suggest that pigeons may derive spatial information from the magnetic field at the release site that could be used to estimate their current position relative to their loft.
Collapse
Affiliation(s)
- Cordula V Mora
- School of Biological Sciences, University of Auckland, Auckland 1142, New Zealand.
| | | |
Collapse
|
43
|
Mehlhorn J, Rehkämper G. Neurobiology of the homing pigeon--a review. Naturwissenschaften 2009; 96:1011-25. [PMID: 19488733 DOI: 10.1007/s00114-009-0560-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Revised: 04/24/2009] [Accepted: 05/13/2009] [Indexed: 10/20/2022]
Abstract
Homing pigeons are well known as good homers, and the knowledge of principal parameters determining their homing behaviour and the neurological basis for this have been elucidated in the last decades. Several orientation mechanisms and parameters-sun compass, earth's magnetic field, olfactory cues, visual cues-are known to be involved in homing behaviour, whereas there are still controversial discussions about their detailed function and their importance. This paper attempts to review and summarise the present knowledge about pigeon homing by describing the known orientation mechanisms and factors, including their pros and cons. Additionally, behavioural features like motivation, experience, and track preferences are discussed. All behaviour has its origin in the brain and the neuronal basis of homing and the neuroanatomical particularities of homing pigeons are a main topic of this review. Homing pigeons have larger brains in comparison to other non-homing pigeon breeds and particularly show increased size of the hippocampus. This underlines our hypothesis that there is a relationship between hippocampus size and spatial ability. The role of the hippocampus in homing and its plasticity in response to navigational experience are discussed in support of this hypothesis.
Collapse
Affiliation(s)
- Julia Mehlhorn
- Study Group Behaviour and Brain, C.&O. Vogt, Institute of Brain Research, University of Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany.
| | | |
Collapse
|
44
|
Kleemann AM, Albrecht J, Schöpf V, Haegler K, Kopietz R, Hempel JM, Linn J, Flanagin VL, Fesl G, Wiesmann M. Trigeminal perception is necessary to localize odors. Physiol Behav 2009; 97:401-5. [PMID: 19303891 DOI: 10.1016/j.physbeh.2009.03.013] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2008] [Revised: 03/09/2009] [Accepted: 03/13/2009] [Indexed: 10/21/2022]
Abstract
The human ability to localize odorants has been examined in a number of studies, but the findings are contradictory. In the present study we investigated the human sensitivity and ability to localize hydrogen sulphide (H(2)S), which in low concentrations stimulates the olfactory system selectively, the olfactory-trigeminal substance isoamyl acetate (IAA), and the trigeminal substance carbon dioxide (CO(2)). A general requirement for testing of localization was the conscious perception of the applied stimuli by the participants. Using Signal Detection Theory, we determined the human sensitivity in response to stimulation with these substances. Then the subjects' ability to localize the three different substances was tested. We found that humans can detect H(2)S in low concentration (2 ppm) with moderate sensitivity, and possess a high sensitivity in response to stimulation with 8 ppm H(2)S, 17.5% IAA, 50% v/v CO(2). In the localization experiment, subjects could localize neither the low nor the high concentration of H(2)S. In contrast, subjects possessed the ability to localize IAA and CO(2) stimuli. These results clearly demonstrate that humans, in spite of the aware perception, are not able to localize substances which only activate the olfactory system independent of their concentration, but they possess an ability to localize odorants that additionally excite the trigeminal system.
Collapse
Affiliation(s)
- A M Kleemann
- Department of Neuroradiology, Ludwig-Maximilians-University of Munich, Germany.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Gagliardo A, Ioalè P, Savini M, Wild M. Navigational abilities of homing pigeons deprived of olfactory or trigeminally mediated magnetic information when young. ACTA ACUST UNITED AC 2008; 211:2046-51. [PMID: 18552292 DOI: 10.1242/jeb.017608] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Anatomical evidence and conditioning experiments have recently suggested that magnetoreceptors are located in the upper beak of homing pigeons, where they are innervated by the ophthalmic branch of the trigeminal nerve. These findings have raised the issue of whether the trigeminally mediated magnetoreception is involved in the navigational mechanisms of homing pigeons. Recent data have shown that, in inexperienced pigeons, section of the ophthalmic branch of the trigeminal nerve does not impair navigational abilities, whereas the navigational performance of inexperienced pigeons is disrupted after section of the olfactory nerve. Nevertheless, the issue of whether the stimuli available during development of the navigational mechanism can influence the types of cues used in determining the direction of displacement remains unresolved. To address this issue, we surgically deprived young pigeons of either olfactory or trigeminally mediated magnetic information, and then later tested their navigational abilities subsequent to an intensive training flight program of up to 10 km in different directions. The birds deprived of trigeminally mediated magnetic information when young developed navigational abilities at the same level as intact control pigeons, whereas the olfactory deprived pigeons displayed randomly scattered initial orientation and poor homing performance. Our data show that olfactory cues are needed for the development of navigational abilities from unfamiliar locations and that the lack of magnetic information does not affect the development of homing abilities.
Collapse
Affiliation(s)
- Anna Gagliardo
- Dipartimento di Biologia, University of Pisa, Via A. Volta 6, Pisa, Italy.
| | | | | | | |
Collapse
|
46
|
Ioalè P, Savini M, Gagliardo A. Pigeon Homing: The Navigational Map Developed in Adulthood is Based on Olfactory Information. Ethology 2008. [DOI: 10.1111/j.1439-0310.2007.01438.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
47
|
Gagliardo A, Ioalè P, Savini M, Lipp HP, Dell'Omo G. Finding home: the final step of the pigeons' homing process studied with a GPS data logger. J Exp Biol 2007; 210:1132-8. [PMID: 17371912 DOI: 10.1242/jeb.003244] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Experiments have shown that homing pigeons are able to develop navigational abilities even if reared and kept confined in an aviary, provided that they are exposed to natural winds. These and other experiments performed on inexperienced birds have shown that previous homing experiences are not necessary to determine the direction of displacement. While the cues used in the map process for orienting at the release site have been extensively investigated, the final step of the homing process has received little attention by researchers. Although there is general agreement on the relevance of visual cues in navigation within the home area, there is a lack of clear evidence. In order to investigate the final step of the homing process, we released pigeons raised under confined conditions and others that had been allowed to fly freely around the loft and compared their flight paths recorded with a Global-Positioning-System logger. Our data show that a limited view of the home area impairs the pigeons' ability to relocate the loft at their first homing flight, suggesting that the final step of the homing process is mediated via recognition of familiar visual landmarks in the home area.
Collapse
Affiliation(s)
- Anna Gagliardo
- Dipartimento di Biologia, University of Pisa, Via Volta 6, 56126 Pisa, Italy.
| | | | | | | | | |
Collapse
|
48
|
Wikelski M, Kays RW, Kasdin NJ, Thorup K, Smith JA, Swenson GW. Going wild: what a global small-animal tracking system could do for experimental biologists. J Exp Biol 2007; 210:181-6. [PMID: 17210955 DOI: 10.1242/jeb.02629] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Tracking animals over large temporal and spatial scales has revealed invaluable and spectacular biological information, particularly when the paths and fates of individuals can be monitored on a global scale. However, only large animals (greater than ∼300 g) currently can be followed globally because of power and size constraints on the tracking devices. And yet the vast majority of animals is small. Tracking small animals is important because they are often part of evolutionary and ecological experiments, they provide important ecosystem services and they are of conservation concern or pose harm to human health. Here, we propose a small-animal satellite tracking system that would enable the global monitoring of animals down to the size of the smallest birds, mammals (bats), marine life and eventually large insects. To create the scientific framework necessary for such a global project, we formed the ICARUS initiative(www.IcarusInitiative.org),the International Cooperation for Animal Research Using Space. ICARUS also highlights how small-animal tracking could address some of the `Grand Challenges in Environmental Sciences' identified by the US National Academy of Sciences, such as the spread of infectious diseases or the relationship between biological diversity and ecosystem functioning. Small-animal tracking would allow the quantitative assessment of dispersal and migration in natural populations and thus help solve enigmas regarding population dynamics,extinctions and invasions. Experimental biologists may find a global small-animal tracking system helpful in testing, validating and expanding laboratory-derived discoveries in wild, natural populations. We suggest that the relatively modest investment into a global small-animal tracking system will pay off by providing unprecedented insights into both basic and applied nature.
Tracking small animals over large spatial and temporal scales could prove to be one of the most powerful techniques of the early 21st century, offering potential solutions to a wide range of biological and societal questions that date back two millennia to the Greek philosopher Aristotle's enigma about songbird migration. Several of the more recent Grand Challenges in Environmental Sciences, such as the regulation and functional consequences of biological diversity or the surveillance of the population ecology of zoonotic hosts, pathogens or vectors, could also be addressed by a global small-animal tracking system.
Our discussion is intended to contribute to an emerging groundswell of scientific support to make such a new technological system happen.
Collapse
Affiliation(s)
- Martin Wikelski
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA.
| | | | | | | | | | | |
Collapse
|
49
|
Phillips K. PIGEONS LED HOME BY THE NOSE. J Exp Biol 2006. [DOI: 10.1242/jeb.02430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|