Migrating animals such as migratory birds are an integral part of ecosystems. However, around 10 billion migratory birds die every year and their habitats are increasingly being threatened by humans. Little is yet known as to which exact route the animals take and what kind of stress they are exposed to. Prof. Dr. Martin Wikelski, director of the Max Planck Institute for Ornithology in Radolfzell and the Department of Ornithology at the University of Konstanz tracks animal migrations using a sophisticated transmission technology. The findings from his research will contribute to animal protection and thus also to biodiversity conservation.
There are different types of migrations. Daily migrants, i.e. animals, marine animals in particular, leave their daytime habitats at night and move from lower water layers to the surface; other animals, birds in particular, are seasonal migrants. Additionally, fish such as tuna follow their prey in order to reach areas with a higher prey population density, thereby acting as a control factor on prey populations and ensuring more food for themselves. This is just one example as to why animal migrations are of major importance to the global ecosystem, as they can help abate insect infestations, control migratory locusts and increase the availability of food for fish. On the other hand, large-scale animal migrations also enhance the global spread of pathogens; in fact, they have been shown to be responsible for the spread of around 70 percent of epidemics and the destruction of entire harvests.
Humans have a massive impact on animal migrations as they take place in heavily human-dominated landscapes. Animals are often trapped and killed for their meat and fur. Human influence has also increasingly led to the destruction of many areas that are used by the animals as intermediate rest stops such as tidelands or wetlands, to name but two examples. “This can lead to the extinction of species whose way of life we know nothing or too little about in order to protect them,” said Prof. Dr. Martin Wikelski, director of the Max Planck Institute (MPI) for Ornithology in Radolfzell.
Researchers from the Radolfzell-based MPI focus on the migratory behaviour of a broad range of different animals, including European storks. “Around 25 years ago, the ornithological station in Radolfzell equipped the first storks with satellite transmitters. This is the longest time period over which individuals of migratory animal species have been monitored,” Prof. Wikelski says. The transmitters have enabled Wikelski and his fellow researchers to monitor more than 250 storks as they migrate between Europe and southern Africa.
The researchers have also started to fit young storks with GPS data loggers and acceleration sensors that enable the migration of the storks and their behaviour throughout their entire lifetime to be monitored for the first time ever. “These data provide us with excellent information about individual alterations of the migration routes,” said Wikelski with great enthusiasm. The researchers found that some individuals hibernate in Eastern Europe, something that storks did not previously do. Wikelski assumes that this has something to do with global warming.
Storks can also be used to show the stress to which migratory animals are exposed during their migrations. The stress already starts in the nesting and breeding grounds where the storks need to find sufficient food to store enough resources for their long travels. Another important factor is the group a stork joins for its journey. “This is crucial as the animals should be flying with individuals with approximately the same bodily constitution to avoid exhaustion and death,” said Wikelski. During their journey, the animals are exposed to bad weather, have to find thermals, cross seas and find a safe resting place at night. The destruction of resting places as a result of human settlement or other issues endangers the migration and survival of the storks.
Prof. Wikelski hopes that the data analysis will provide him and his team with new insights and ideas about where the animals rest and what they need to survive. “This helps us protect the storks’ most important resting places and hibernating areas. Such analyses are not yet possible for other migratory birds, as we still lack the necessary data,” said the ornithologist.
There are several reasons why so little is known about the migration of many animals. “Permanent monitoring has previously not been possible, mainly for technical reasons,” Wikelski said. The transmitters that were previously used were able to transmit parameters such as the animal’s position or medical parameters. “However, they were too heavy to be suitable for small animals. The first models weighed several kilogrammes,” Wikelski said. The visual observation of relatively small and timid animals is rather difficult as they are usually perfectly camouflaged within their environment. In order to obtain greater insights into the migratory behaviour of small animals, Wikelski and colleagues are developing new technologies for the telemetric transmission of animal data.
In cooperation with other researchers, Wikelski established the ICARUS initiative (International Cooperation of Animal Research Using Space) whose mission is to establish a remote sensing platform for scientists worldwide that track small animals around the globe. The idea was developed in collaboration with researchers from the University of Illinois where animal telemetry originated in the early 1960s. ICARUS is a global observation system onboard the International Space Station (ISS) that is capable of tracking even very small animals. As the project involves a large number of small animals, the research will provide new insights into how animals cope with the effects of climate change, disease and man-made alterations to their environment, and also enable safety and protection measures to be augmented. The ICARUS project is currently being implemented and will probably be ready for use in 2016. New concepts that will enable the rapid conversion of data into technological progress will be developed and tested. “The system will help us to monitor thousands of animals and even the migration of insects,” said Wikelski summarising the benefits of ICARUS.
Max Planck Institute for Ornithology
Prof. Dr. Martin Wikelski
Am Obstberg 1