Connect with us

Conservation Africa News Magazine | African Wildlife & Conservation News

Conservation Africa News Magazine | African Wildlife & Conservation News

Conservation Africa News – Wonders of animal migration: How sea turtles find small, isolated islands


Conservation Africa News

Conservation Africa News – Wonders of animal migration: How sea turtles find small, isolated islands

The routes of 35 adult female green turtles traveling to their foraging grounds in the Western Indian Ocean after the end of the nesting season on Diego Garcia, Chagos Archipelago. Turtles tracked in different years are indicated by different colors. Stars = final foraging site, crosses = turtles not tracked all the way to their…

Conservation Africa News – Wonders of animal migration: How sea turtles find small, isolated islands

Conservation Africa News –

Conservation Africa News - Wonders of animal migration: How sea turtles find small, isolated islands
The routes of 35 adult female green turtles traveling to their foraging grounds in the Western Indian Ocean after the end of the nesting season on Diego Garcia, Chagos Archipelago. Turtles tracked in different years are indicated by different colors. Stars = final foraging site, crosses = turtles not tracked all the way to their foraging grounds. Credit: Nicole Esteban, Swansea University

One of Charles Darwin’s long-standing questions on how turtles find their way to islands has been answered thanks to a pioneering study by scientists.

A team from Deakin University, University of Pisa and Swansea University equipped 33 green sea turtles with satellite tags and recorded unique tracks of green turtles migrating long distances in the Indian Ocean to small oceanic islands.

The study provides some of the best evidence to date that migrating sea turtles have an ability to redirect in the open ocean, but only at a crude level rather than at fine scales.

Seven turtles traveled only a few tens of kilometers to foraging sites on the Great Chagos Bank, six traveled over 4,000km to mainland Africa, one to Madagascar, while another two turtles ventured north to the Maldives.

Most of the species tracked (17) migrated westward to distant foraging sites in the Western Indian Ocean that were associated with small islands.

It shows that the turtles can travel several hundred kilometers off the direct routes to their goal before reorienting, often in the open ocean.

In 1873, Charles Darwin marveled at the ability of sea turtles to find isolated islands where they nest. However, the details of how sea turtles, and other groups such as seals and whales, navigate during long migrations remains an open question.






Animated tracks of 35 green turtle migrations tracked from nesting beaches in the Chagos Archipelago (Indian Ocean). The year of migration is indicated by colors; red = 2012, black = 2015, orange = 2017 and blue = 2018. Stars (n=33) indicate migration endpoints and incomplete migrations (n=2) are denoted by black crosses. Animation timing has been adjusted so that turtles from all years depart nesting beaches at the same time and migration duration in days is indicated by the counter in the lower right hand corner of the video frame. Of 35 equipped turtles, 33 were tracked all the way to their foraging grounds. The animation highlights the often circuitous routes of individual turtles. Credit: Nicole Esteban, Swansea University

Answering this question using free-living individuals is difficult due to thousands of sea turtles being tracked to mainland coasts where the navigational challenges are easiest.

The study also showed that turtles frequently struggled to find small islands, overshooting, and/or searching for the island in the final stages of migration.

These satellite tracking results support the suggestion, from previous laboratory work, that turtles use a crude true navigation system in the open ocean, possibly using the world’s geomagnetic field.

Swansea University’s Dr. Nicole Esteban, a co-author in the study said:

“We were surprised that green turtles sometimes overshot their ultimate destination by several hundred kilometers and then searched the ocean for their target. Our research shows evidence that turtles have a crude map sense with open ocean reorientation.”



More information:
Jeanne A. Mortimer et al. Estimates of marine turtle nesting populations in the south-west Indian Ocean indicate the importance of the Chagos Archipelago, Oryx (2020). DOI: 10.1017/S0030605319001108

Citation:
Wonders of animal migration: How sea turtles find small, isolated islands (2020, July 16)
retrieved 19 July 2020
from https://phys.org/news/2020-07-animal-migration-sea-turtles-small.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

The Most Powerful Sale & Affiliate Platform Available!

There's no credit card required! No fees ever.

Create Your Free Account Now!

Subscribe to the newsletter news

We hate SPAM and promise to keep your email address safe

Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *

Top Stories

Importance of Wildlife Conservation

Conservation Awareness

Importance of Wildlife Conservation

By July 30, 2020
Wildlife Conservation Volunteer - Caring For Native Wildlife
Wildlife Conservation Awareness – Congress wants to fix public lands. It’s just a bandage on the wounds Trump caused | Sally Jewell and Ken Salazar
Wildlife Conservation Awareness – Times Evoke: ‘Our apathy threatens biodiversity’
Wildlife Conservation Awareness – U.S. Congress approves conservation bill
Wildlife Conservation Awareness – Black Rhino Academy / NLÉ
Wildlife Conservation Awareness – This 12-year-old bottle terrarium is teeming with lush life
Wildlife Conservation Awareness – Animals Appreciate Recent Traffic Lull
Wildlife Conservation Awareness – As New York COVID-19 Hospitalizations Drop, Gov. Cuomo Urges Vigilance
Wildlife Conservation Awareness – Rewilding immunology
Wildlife Conservation Awareness – Grizzly bears in the dark as they try to share living space with humans: study – Airdrie Today
Wildlife Conservation Awareness – Maharashtra: Tillari area in Sindhudurg declared conservation reserve
Wildlife Conservation Awareness – Scientists call for pandemic investigations to focus on wildlife trade
Wildlife Conservation Awareness – Scientists call for pandemic investigations to focus on wildlife trade

Tags

Importance of Wildlife Conservation

Conservation Awareness

Importance of Wildlife Conservation

By July 30, 2020
Conservation Africa News – Friday Five with Olubunmi Adeyemi
Wildlife Conservation Society – Does it pay to protect nature? A new study weighs in – Reuters.com
Wildlife Conservation Volunteer - Caring For Native Wildlife
Conservation Africa News – Botswana finds more dead elephants, says test results due this week – Reuters
Conservation Africa News – Daily briefing: “The pandemic is gaining full momentum” in Africa
Corona Virus Outbreak
Conservation Africa News – Timeline: How the coronavirus pandemic unfolded – Reuters India
Wildlife Conservation Society – David Attenborough in appeal to save charity behind London Zoo – Reuters
Conservation Africa News – Pangolin protectors, an inflatable lab and young stars — June’s best science images
Conservation Africa News – Listening to nature: Notes from Session 1 of TED2020
Wildlife Conservation Awareness – Congress wants to fix public lands. It’s just a bandage on the wounds Trump caused | Sally Jewell and Ken Salazar
Conservation Africa News – One Tree Planted And The Jane Goodall Institute Announce Partnership On Critical Restoration Project In Africa
Conservation Africa News – Graffiti Artist Turns South African Towns Into Open-Air Galleries
To Top