17 Oct 2019

Novel study identifies key foraging areas of Cambridge scientists

Our Marine science team came up with an innovative way of explaining the concept of marine Important Bird & Biodiversity Areas to BirdLife staff - by fitting them with GPS trackers on their lunch break.

© Unsplash
© Unsplash
By Cressida Stevens

Yes, you read that right: the researchers have become the researched. Our Marine Science team were tasked with explaining the significance of marine Important Bird and Biodiversity Areas (IBAs) to those with no existing knowledge of tracking technology or bird hotspots. Demystifying such scientific concepts often proves difficult but our scientists came up with an imaginative solution. By fitting their colleagues with GPS trackers they answered the top questions of a non-specialist concerning seabird tracking and IBAs, in terms of a universally relatable scenario: the pursuit of a good lunch.

 

Why do seabirds need to be tracked?

Since the oceans are so incredibly vast, when birds head out to sea it is difficult to know where they go and where they face danger. Similarly, when BirdLife's UK staff head out of their offices onto the streets of Cambridge, they become lost within a bustling sea of people. To identify their colleagues’ Important Lunching Areas (ILAs), our scientists needed to assess their foraging patterns and feeding areas. This would be near impossible through direct observation, so instead they used tracking devices. Just as tracking tags allow us to pick our colleagues out of the crowd, they also allow us to follow exactly where tagged birds go as they soar over the open ocean. Although seabirds range very widely, they often aggregate in particular areas and identifying these areas is essential to effective marine conservation.

 

How do we track seabirds?

It is only with relatively recent advances in technology that we have been able to gather information remotely about where birds go - the first satellite tracking devices small and light enough to attach to seabirds were developed in the 1980s. Before then, recovered bird rings and observations on boats suggested albatrosses and petrels were being killed at fisheries hundreds or even thousands of miles away from their breeding colonies. But only when these tracking devices were first deployed on albatrosses was the great degree of overlap between their foraging areas and fishing fleets revealed, confirming some fisheries as a major threat to seabirds. There are now various types of devices for tracking animals of all shapes and sizes. Fortunately, these tags are also viable in studies of humans and our scientists were able to use GPS loggers to investigate their colleagues’ foraging distributions.

 

How are IBAs/ ILAs identified?

The scientists applied the same methods to the human data that they would to that of tagged seabirds. They took the data from BirdLife staff and split it into individual journeys, to identify the core areas visited by our team on their lunch hour. For an area to become an IBA, it needs to meet one of four threshold criteria. Often for seabirds, this is a minimum percentage of the population visiting a given area. On this basis, our scientists identified four ILAs for BirdLife staff: the market square, the area around Jack’s Gelato ice-cream shop and Aromi (a popular Italian deli), a nearby shopping centre and the wall outside King’s College – a place many go to sit while they eat.

 

Routes were mapped to reveal key lunchtime foraging areas of BirdLife staff

 

It should be noted that recordings were taken during the summer, and winter foraging distributions may be quite different. For example, in colder weather individuals may favour stopping by a cosy café for a hot chocolate rather than tucking into a gelato. Similarly, the distributions of bird populations tend to vary between seasons and different stages of their life cycle, so in order to get a complete picture of their movements we must track birds at different times of the year.

 

Why do we need IBAs?

Understanding which areas are most important to birds, or humans for that matter, is essential for making informed planning decisions. For example, if there were a proposal to build a wind farm within Cambridge’s market square, our science team would point out that this might disturb the behaviour of BirdLife International staff and may leave them unable to find sufficient food. In the same way, identifying important areas for birds at sea enables us to direct conservation efforts for them where they are most needed and inform marine spatial planning. IBAs are also useful in establishing Marine Protected Areas, where wildlife are protected by law from certain threats. BirdLife International have been compiling this vital information, contributed by scientists worldwide, into their Seabird Tracking Database. Originally containing data solely for albatrosses and petrels, it now holds tracking information for 120 species of seabird and is fundamental to marine conservation efforts.

We all have places that are especially significant to us, be it our favourite restaurant, favourite café or green space – somewhere that we would never want to see shut down or replaced. However, for some bird species, it’s not just a case of their favourite place to go, but one of the only places they can go. We hope that by finding and protecting these crucial areas we can reverse the declining population trends of seabirds globally.