New research has found that adult sea-turtle migrations and their selection of feeding sites are directly influenced by their past experiences as little hatchlings adrift in ocean currents.
When they breed, adult sea turtles return to the beach where they were born. After breeding, adult sea turtles typically migrate several hundreds to thousands of kilometres to their feeding habitats. However, there has been little information about how turtles chose their feeding sites. For example, some turtles migrate to feeding habitats thousands of kilometres away, while other turtles don't migrate or feed in the open ocean.
This is a new-born loggerhead turtle.
Credit: Dr. Rebecca Scott
The study, which involves the University of Southampton, looked at what habitats the turtles would have experienced as juveniles. New-born hatchling sea turtles are too small to track with satellite tags. However, when they emerge from their eggs, they head to the ocean and drift with ocean currents to their juvenile development habitats. The researchers combined all the available satellite tracking data on adult turtles with models of how the world's sea water moves past nesting sites to study where the hatchling sea turtles drift to.
By comparing global patterns in the migrations of all satellite tracked sea turtles with global hatchling drift patterns, they showed that adult sea turtle migrations and foraging habitat selections were based on their past experiences drifting with ocean currents.
Dr Rebecca Scott, who led the study soon to be reported in the journal Ecology, says: "Hatchlings' swimming abilities are pretty weak, and so they are largely at the mercy of the currents. If they drift to a good site, they seem to imprint on this location, and then later actively go there as an adult; and because they're bigger and stronger they can swim there directly," explained Dr Scott, who is based at the GEOMAR Helmholtz Centre for Ocean Research in Kiel, Germany.
"Conversely, if the hatchlings don't drift to sites that are suitable for adult feeding, you see that reflected in the behaviour of the adults, which either do not migrate or they feed in the open ocean, which is not the normal strategy for most turtle species."
Many animal groups undertake great migrations, and the process of learning where to go on these travels can take several forms. For example, some juvenile whales and birds learn migration routes by following their mothers or more experienced group members, whilst other bird and insect species seem to be born with the information or a map sense that informs them where they should migrate.
However, neither of these strategies works for turtles. Once the adult female has laid her eggs on a beach, her involvement in her offspring's development ends. When the hatchlings crawl down the beach into the water, they are on their own; there is no experienced turtle to follow, and they go where the ocean takes them.
Dr Bob Marsh from the University of Southampton, who was Dr Scott's supervisor and co-author of the study, said: "Although it is known that ocean currents have a large influence on the dispersion of small planktonic organisms, these findings reveal ocean currents also directly shape some the migrations of some of the largest, most powerful long distance migrants in the animal kingdom."
Glenn Harris | Eurek Alert!
Preservation of floodplains is flood protection
27.09.2017 | Technische Universität München
Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research