May 1, 2013
Researchers Discover Migration Habits Of Manx Shearwater Seabird
Brett Smith for redOrbit.com - Your Universe Online
Using cutting-edge tracking devices and data analysis techniques, a group of UK researchers has discovered new migration habits of the Manx Shearwater, a small seabird.
Scientists at the University College London (UCL) and the University of Oxford collected data over three consecutive years to reveal the birds´ complex pattern of rest, flight and foraging, according to their report in journal Interface.
"Understanding the behavior of these birds during migration is crucial for identifying important at-sea locations and for furthering conservation efforts,” said lead author Robin Freeman, from the UCL´s Centre for Mathematics and Physics in the Life Sciences and Experimental Biology. “By tracking the movements, foraging behavior and environmental drivers of such species, and developing new techniques to do so is critical as they continue to be subject to environmental and anthropogenic pressure."
"Methods to understand animal behavior from complex data series — what we're calling 'ethoinformatics' - are increasingly important as we continue to gather large amounts of data about animals in the wild,” he added.
In the study, the birds were equipped with miniature geolocators and lightweight GPS devices capable of recording continuously for many years and weighing less than a tenth of an ounce. Developed by the British Antarctic Survey (BAS), the devices are superior to others because of their overall cost, weight and longevity. They were also able to record salt-water immersion and light level data.
Using GPS tracking data collected during the breeding season, the team showed that migratory behaviors could be predicted based solely on information collected by the much smaller immersion-loggers.
The data also identified areas of high foraging behavior off south-eastern Brazil during the birds´ southbound winter journey and in the Western Atlantic during their springtime return to the British Isles. The researchers were also able to locate the birds´ popular rest stops, found primarily towards the end of their route in both directions. These rest stops could be to take advantage of the high prey availability or to recover from long flight periods, the team theorized.
The researchers also found a correlation between the birds' behavior and various environmental conditions, particularly for primary production, or the rate at which all the plants in an area produce useful energy. Resting behaviors were found to take place in highly productive waters compared to other activities.
Professor Tim Guilford, who led the team at the University of Oxford, said the study not only found new behaviors for a highly migratory bird, it also revealed the usefulness of the new data analysis techniques.
"At the Oxford navigation group, we have been able to gather an unprecedented amount of information about these elusive ocean wanderers,” he said. “We trying to understand the processes that govern the behavior seabirds at sea, and the decisions they must make during migration and foraging."
"We're very excited about these new techniques and their application to understanding the behavior of such and important and captivating bird,” Freeman added. “This is just the beginning of our on-going investigation into understanding the behavior of these animals in the wild."