Regional Magnetic Fields as Navigational Markers for Sea Turtles

  title={Regional Magnetic Fields as Navigational Markers for Sea Turtles},
  author={Kenneth J. Lohmann and Shaun D. Cain and S A Dodge and Catherine M. F. Lohmann},
  pages={364 - 366}
Young loggerhead sea turtles (Caretta caretta) from eastern Florida undertake a transoceanic migration in which they gradually circle the north Atlantic Ocean before returning to the North American coast. Here we report that hatchling loggerheads, when exposed to magnetic fields replicating those found in three widely separated oceanic regions, responded by swimming in directions that would, in each case, help keep turtles within the currents of the North Atlantic gyre and facilitate movement… 

The magnetic map of hatchling loggerhead sea turtles

Simulating transoceanic migrations of young loggerhead sea turtles: merging magnetic navigation behavior with an ocean circulation model

Findings imply that even weakly swimming marine animals may be able to exert strong effects on their migratory trajectories and open-sea distributions through simple navigation responses and minimal swimming.

Orientation of hatchling loggerhead sea turtles to regional magnetic fields along a transoceanic migratory pathway

Hatchlings were exposed to several additional magnetic fields that exist along or outside of the North Atlantic Gyre's northern boundary, consistent with the hypothesis that loggerhead turtles entering the sea for the first time possess a navigational system in which a series of regional magnetic fields sequentially trigger orientation responses that help steer turtles along the migratory route.

Magnetic orientation by hatchling loggerhead sea turtles (Caretta caretta) from the Gulf of Mexico

The results suggest that migration inside Gulf waters may be circuitous, that the turtles respond appropriately to enter Atlantic waters, and that orientation along Florida’s east coast probably promotes transport by the Gulf Stream into the North Atlantic gyre.

Magnetic Orientation and Navigation in Marine Turtles, Lobsters, and Molluscs: Concepts and Conundrums1

Findings in the brain of T. diomedea represent an encouraging step toward a holistic understanding of the cells and circuitry that underlie magnetic orientation behavior in one model organism.

Longitude Perception and Bicoordinate Magnetic Maps in Sea Turtles

Sea Turtles: Navigation and Orientation

The geomagnetic environment in which sea turtle eggs incubate affects subsequent magnetic navigation behaviour of hatchlings

It is demonstrated for the first time that the magnetic environment present during early development can influence the magnetic orientation behaviour of a neonatal migratory animal.

Region-specific magnetic fields structure sea turtle populations

The approach reveals parallel but not universal use of geomagnetic cues in sea turtles, and describes magneto-sensing regions as characterized by sharp clines of total and vertical field intensity vectors offering the navigation cues that increase philopatric accuracy and promote genetic structuring among sea turtle populations.

Magnetic navigation behavior and the oceanic ecology of young loggerhead sea turtles

The findings suggest that the magnetic navigation behavior of sea turtles is intimately tied to their oceanic ecology and is shaped by a complex interplay between ocean circulation and geomagnetic dynamics.



Migratory guidance mechanisms in marine turtles

Hatchling sea turtles from eastern Florida, U.S.A., appear to use three different sets of orientation cues sequentially as they migrate offshore, and adults may exploit geomagnetic features in one of several different ways to guide themselves into the vicinity of a nesting area.

Long-distance navigation in sea turtles

Adult sea turtles of several species migrate across vast expanses of ocean to arrive at specific nesting areas and feeding sites. Two hypotheses have been proposed to account for this remarkable


  • Lohmann
  • Environmental Science
    The Journal of experimental biology
  • 1994
It is hypothesized that hatchlings initially establish a seaward course using visual cues available on or near land, then maintain the course using magnetic cues as they migrate into the open sea, and that light cues can set the preferred direction of magnetic orientation by loggerhead hatchlings.

Estimating the age of juvenile loggerhead sea turtles in the North Atlantic

Their trans-Atlantic drift time was estimated using data from satellite-tracked buoys and from a mathematical model and, hence, it was estimated that the modal age of these juvenile turtles was between 1.80 and 3.75 years.

Detection of magnetic field intensity by sea turtles

WHETHER migratory animals can determine their global position by detecting features of the Earth's magnetic field has long been debated1–4. To do this an animal must perceive (at least) two distinct


  • Lohmann
  • Environmental Science, Geology
    The Journal of experimental biology
  • 1994
It is demonstrated that sea turtles can distinguish between different magnetic inclination angles and perhaps derive from them an approximation of latitude.

New Perspectives on the Pelagic Stage of Sea Turtle Development

It is now obvious that when young cultured sea turtles are released in so-called head-starting projects, the release sites ought to be chosen with the greatest care, and it is also necessary to avoid release localities where the convergence habitat may carry heavy loads of material.

Evolution of Body Size in the Woodrat over the Past 25,000 Years of Climate Change

Microevolutionary changes in the body size of the bushy-tailed woodrat (Neotoma cinerea) since the last glacial maximum were estimated from measurements of fecal pellets preserved in paleomiddens

Navigation in context: grand theories and basic mechanisms

This work aims to use modern recording technology to unravel the detailed spatial and temporal structures of migratory routes and foraging trajectories, study the animal's sensory and computational abilities by combining behavioural and neurophysiological approaches, and work bottom-up, as evolution did, by trying to integrate the individual navigational methods.