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!
Protecting fisheries from evolutionary change
27.04.2016 | International Institute for Applied Systems Analysis (IIASA)
From waste to resource – how can we turn garbage into gold?
27.04.2016 | DLR Projektträger
Using an ultra fast-scanning atomic force microscope, a team of researchers from the University of Basel has filmed “living” nuclear pore complexes at work for the first time. Nuclear pores are molecular machines that control the traffic entering or exiting the cell nucleus. In their article published in Nature Nanotechnology, the researchers explain how the passage of unwanted molecules is prevented by rapidly moving molecular “tentacles” inside the pore.
Using high-speed AFM, Roderick Lim, Argovia Professor at the Biozentrum and the Swiss Nanoscience Institute of the University of Basel, has not only directly...
If a person pushes a broken-down car alone, there is a certain effect. If another person helps, the result is the sum of their efforts. If two micro-particles are pushing another microparticle, however, the resulting effect may not necessarily be the sum their efforts. A recent study published in Nature Communications, measured this odd effect that scientists call “many body.”
In the microscopic world, where the modern miniaturized machines at the new frontiers of technology operate, as long as we are in the presence of two...
Researchers from the Max Planck Institute Stuttgart have developed self-propelled tiny ‘microbots’ that can remove lead or organic pollution from contaminated water.
Working with colleagues in Barcelona and Singapore, Samuel Sánchez’s group used graphene oxide to make their microscale motors, which are able to adsorb lead...
Neutron scattering and computational modeling have revealed unique and unexpected behavior of water molecules under extreme confinement that is unmatched by any known gas, liquid or solid states.
In a paper published in Physical Review Letters, researchers at the Department of Energy's Oak Ridge National Laboratory describe a new tunneling state of...
Honeycomb structures as the basic building block for industrial applications presented using holo pyramid
Researchers of the Alfred Wegener Institute (AWI) will introduce their latest developments in the field of bionic lightweight design at Hannover Messe from 25...
27.04.2016 | Event News
15.04.2016 | Event News
12.04.2016 | Event News
04.05.2016 | Physics and Astronomy
04.05.2016 | Physics and Astronomy
04.05.2016 | Materials Sciences