A groundbreaking study has revealed that bottlenose dolphins possess the ability to perceive weak electric fields, using vestiges of their neonatal whiskers. This revelation, highlighting their capability to detect both constant and varying electric fields, offers a fresh perspective on their hunting techniques and potential use of Earth’s magnetic field for navigation.
The newfound electrosensitivity in bottlenose dolphins could play a role in their global navigation abilities.
At birth, appearing tail-first, bottlenose dolphin calves sport two thin lines of whiskers on their snout, resembling the tactile whiskers found in seals. These whiskers, however, are shed shortly after birth, leaving behind small indentations called vibrissal pits.
Tim Hüttner and Guido Dehnhardt from the University of Rostock, Germany, hypothesized that these pits might serve a greater purpose, potentially enabling adult dolphins to detect faint electric fields.
Upon closer examination, they noticed that these residual pits share similarities with structures in sharks that detect electric fields. Testing this theory with captive bottlenose dolphins, they confirmed that the dolphins could indeed feel electric fields in water.
Electrosensitivity in Dolphins: An Epochal Finding
“The experience was astounding,” says Dehnhardt, who documented this significant finding and its potential applications in the Journal of Experimental Biology on November 30, 2023.
To explore the dolphins’ sensitivity to electric fields produced by aquatic organisms, Dehnhardt and Hüttner collaborated with Lorenzo von Fersen at Nuremberg Zoo and Lars Miersch at the University of Rostock. They tested two dolphins, Donna and Dolly, exposing them to varying electric fields to determine if they could detect a fish concealed beneath the sandy ocean floor.
After training each dolphin to rest its jaw on a metal bar underwater, Hüttner, Armin Fritz (Nuremberg Zoo), and their team taught the dolphins to swim away upon sensing an electric field emitted by electrodes near their snout. They progressively reduced the electric field intensity from 500 to 2μV/cm and observed the dolphins’ reactions. Donna and Dolly displayed equal sensitivity to stronger fields, responding accurately almost every time. The distinction became clear at lower field strengths, where Donna detected fields as weak as 2.4μV/cm, while Dolly perceived fields at 5.5μV/cm.
Further Investigations: Fluctuating Electric Fields
But living creatures produce electric fields that aren’t static. Notably, the movement of fish gills causes electric fields to vary. The team then wondered if Donna and Dolly could also detect these fluctuating fields. They tested the dolphins with electric fields pulsing at different frequencies while diminishing the field strength. The dolphins could indeed perceive these fields, though they were less sensitive to them compared to steady electric fields. Dolly detected the slowest pulsing field at 28.9μV/cm, while Donna sensed all pulsating frequencies, the slowest at 11.7μV/cm.
Implications of Dolphins’ Electrosensitivity
This newly discovered electrosensitivity in dolphins could have practical implications. According to Dehnhardt, “This ability to sense faint electric fields aids dolphins in locating fish buried in the sediment during the final moments before capture,” a contrast to sharks who can sense electric fields from fish within a range of 30–70cm. Hüttner and Dehnhardt also propose that this sensory skill could assist dolphins in orienting themselves in relation to the Earth’s magnetic field.
Dehnhardt notes, “Toothed whales could use this sense to orient themselves with the Earth’s magnetic field,” suggesting that dolphins swimming through weak magnetic field regions at a normal speed of 10m/s could generate an electric field of 2.5μV/cm across their bodies. Faster swimming speeds could further enhance their ability to detect the Earth’s magnetic field, potentially allowing them to navigate globally using a magnetic map.
Reference: “Passive electroreception in bottlenose dolphins (Tursiops truncatus): implication for micro- and large-scale orientation” by Tim Hüttner, Lorenzo von Fersen, Lars Miersch and Guido Dehnhardt, 30 November 2023, Journal of Experimental Biology.
DOI: 10.1242/jeb.245845
Table of Contents
Frequently Asked Questions (FAQs) about Electrosensitivity in Dolphins
Can bottlenose dolphins detect electric fields?
Yes, bottlenose dolphins have been discovered to have the ability to detect weak electric fields. This capability is thought to be a result of remnants of their neonatal whiskers, known as vibrissal pits, which are left after the whiskers fall out soon after birth.
How does this electric sense in dolphins aid in their hunting?
The electric sense in dolphins assists them in detecting fish hidden in the ocean sediment. This sense is particularly useful in the final moments before they capture their prey, allowing them to locate fish that are not visible or directly accessible.
What does the discovery about dolphins’ electric sense imply for their navigation abilities?
Researchers suggest that the ability of dolphins to sense electric fields could also play a role in their global navigation. This is based on the hypothesis that swimming through the Earth’s magnetic field could generate detectable electric fields across their bodies, aiding in orientation and navigation.
How was this electrosensory ability in dolphins tested?
The electrosensory ability was tested by having dolphins respond to electric fields in water. Researchers trained dolphins to swim away from a submerged metal bar upon sensing an electric field produced by electrodes near their snout. The sensitivity of the dolphins to various strengths of electric fields was then measured.
Who conducted the research on dolphins’ electrosensitivity?
The research was conducted by Tim Hüttner and Guido Dehnhardt from the University of Rostock, Germany, along with collaborators from Nuremberg Zoo and the University of Rostock. Their findings were published in the Journal of Experimental Biology on November 30, 2023.
More about Electrosensitivity in Dolphins
- Electric Sensing in Dolphins
- Bottlenose Dolphins and Electric Fields
- Marine Biology Research on Dolphins
- Dolphin Navigation and Electrosensitivity
- Journal of Experimental Biology Article
- University of Rostock Dolphin Study
- Electrosensitivity in Marine Mammals
6 comments
wow, never knew dolphins had such cool abilities, guess theres more to them than just being cute and smart.
This is fascinating stuff! Dolphins detecting electric fields? nature is full of surprises.
Their navigation skills must be amazing with this kind of sensory perception. Dolphins continue to amaze me.
I read about sharks having similar abilities, dolphins too? that’s incredible. gotta love marine life!
Great article but are we sure about the electric field strengths mentioned here? Seems a bit off from what I remember in my studies…
hey, does this mean dolphins can ‘see’ the magnetic field of the earth? that would be so cool, like a built-in GPS system.