Superparamagnetic Magnetite in the Upper Beak Tissue of Homing Pigeons

  title={Superparamagnetic Magnetite in the Upper Beak Tissue of Homing Pigeons},
  author={Marianne Hanzlik and Ch Heunemann and Elke Holtkamp-R{\"o}tzler and Michael Winklhofer and Nikolai P. Petersen and Gerta Fleissner},
Homing pigeons have been subject of various studies trying to detect magnetic material which might be involved in magnetic field perception. Here we focus on the upper-beak skin of homing pigeons, a region that has previously been shown to contain nerves sensitive to changes of the ambient magnetic field. We localized Fe3+ concentrations in the subcutis and identified the material by transmission electronmicroscopy (TEM) as aggregates of magnetite nanocrystals (with grain sizes between 1 and 5… 
Hypothetical superparamagnetic magnetometer in a pigeon’s upper beak probably does not work
The results indicate that magnetite clusters, constituted by superparamagnetic nanoparticles and observed in a pigeon’s upper beak, may not be a component of a measuring system providing the magnetic map.
Ultrastructural analysis of a putative magnetoreceptor in the beak of homing pigeons
The subcellular organization of afferent trigeminal terminals in the upper beak of the homing pigeon, Columba livia, which are about 5 μm in diameter and contain superparamagnetic magnetite (SPM) crystals was investigated.
Avian magnetite-based magnetoreception: a physiologist's perspective
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.
Clusters of iron-rich cells in the upper beak of pigeons are macrophages not magnetosensitive neurons
It is shown that clusters of iron-rich cells in the rostro-medial upper beak of the pigeon Columbia livia are macrophages, not magnetosensitive neurons, which necessitates a renewed search for the true magnetite-dependent magnetoreceptor in birds.
Micromagnetic insight into a magnetoreceptor in birds: existence of magnetic field amplifiers in the beak.
The proposed receptor theoretically is studied and the criteria for which it becomes operational and can be used for registering the weak magnetic fields as, e.g., the geomagnetic field, by a bird is formulated.
Avian Magnetoreception: Elaborate Iron Mineral Containing Dendrites in the Upper Beak Seem to Be a Common Feature of Birds
The magnetic field sensors enabling birds to extract orientational information from the Earth's magnetic field have remained enigmatic. Our previously published results from homing pigeons have made
The magnetic properties of tissue samples and iron-rich organelles from the pigeon Columba livia / Daniel Kagerbauer
This study investigates the magnetic properties of ferritin and a variety of pigeon tissues using Superconducting Quantum Interference Device (SQUID) magnetometry, and modelled the magneto-electric properties of an iron-rich organelle, the cuticulosome, implicated in the magnetic sense.
Magnetic pulse affects a putative magnetoreceptor mechanism.
A physical model that accurately predicts the dynamics of interacting SP clusters in a magnetic field offers a novel mechanism for magnetic field perception and is in agreement with the response of birds observed after magnetic-pulse treatments.
A novel concept of Fe-mineral-based magnetoreception: histological and physicochemical data from the upper beak of homing pigeons
Animals make use of the Earth’s magnetic field for navigation and regulation of vegetative functions; however, the anatomical and physiological basis for the magnetic sense has not been elucidated


Ferromagnetic coupling to muscle receptors as a basis for geomagnetic field sensitivity in animals
The detection of permanently magnetic material in the neck musculature of pigeons and migratory white-crowned sparrows is reported and it is proposed that a magnetic field detector might involve the coupling of magnetic particles to a sensitive muscle receptor such as a spindle.
Magnetic responses of the trigeminal nerve system of the bobolink (Dolichonyx oryzivorus)
Magnetite in Denticle Capping in Recent Chitons (Polyplacophora)
Preliminary data are presented on the physical properties and the mineralogy of the material in denticle caps of chitons. The X-ray diffraction patterns of the denticle material indicate the presence
Magnetic blocking temperatures of magnetite calculated with a three‐dimensional micromagnetic model
We present an analysis of thermal stability of magnetic remanence in fine grains of magnetite (grain size d = 15–120 nm). In order to model incoherent transitions between single-domain (SD) and
Neural basis of the magnetic compass: interactions of visual, magnetic and vestibular inputs in the pigeon's brain
It is indicated, that information provided by magnetic cues in the earth's strength range may be conveyed from the visual to the vestibular system via a projection from the nBOR and then related to active movements of the animal.
Theoretical single‐domain grain size range in magnetite and titanomagnetite
A theoretical model of single-domain (SD) grain sizes is applied to magnetite and titanomagnetite. In this model, transition to a two-domain configuration takes place at the SD threshold d0. This
We have performed magnetic measurements on a diluted system of $\ensuremath{\gamma}\ensuremath{-}{\mathrm{Fe}}_{2}{\mathrm{O}}_{3}$ nanoparticles $(d\ensuremath{\sim}7 \mathrm{nm})$, and on a
Magnetotactic bacteria.
Bacteria with motility directed by the local geomagnetic field have been observed in marine sediments and may contain novel structured particles, rich in iron, within intracytoplasmic membrane vesicles that impart to cells a magnetic moment.
Magnetic Orientation in Animals
This text details animal orientation with the help of information from the geomagnetic field. It reviews the magnetic effects on spatial behaviour in the various groups of the animal kingdom from