Do wintering conditions in Africa constrain migratory birds’ ability to respond to climate change?

Field-ecological research in Ivory Coast

‘Being at the right time at the right place’.

Timing is key to all major animal migrations, allowing organisms to make best use of seasonal changes on earth. It seems paradoxical that especially long-distance migrants with their incredible movements are under pressure now that environments change rapidly at different places along their migratory paths. We study the migratory pied flycatcher, Ficedula hypoleuca, and how African winter conditions affect their ability to keep track of climate warming at their breeding sites. Like billions of birds, flycatchers migrate thousands of kilometers between temperate breeding grounds in Europe and wintering grounds in Africa. Unfortunately, forested habitats at many of these wintering sites are undergoing rapid deforestation.There is an important knowledge gap in our understanding about how migrant birds deal with such changes at different ends of their flyway.

Janne Ouwehand and Flycatcher
forest comoe march 2018 2.JPG
Woodland savanna at Comoé National Park

The support of a National Geographic Society Explorer grant provided a great opportunity to study the role of wintering grounds on preparations and decisions-making for flycatchers. Janne Ouwehand, and her fellow explorers Wender Bil, Sander Bot and Assia Kraan travelled in 2018 and 2019 to the wintering grounds of the pied flycatchers in Comoé National Park, Ivory Coast.What do they need to be well prepared for the journey? When do they fly? Will they be in time for spring in their breeding grounds? We hope that their migratory life-style is flexible enough to deal with these changes. However, these birds might be multiple jeopardy: if ongoing large-scale deforestation in West Africa deteriorates high quality wintering habitats, this may subsequently constrain birds to depart at the optimal time and prevent further advancement of breeding to track spring warming. Alternatively, the quality of their wintering grounds may not be constraining the adaptation of flycatchers, or may only be doing so in dry years.

To follow the movements of flycatchers across the year, we equipped birds with tiny geolocator back-packs. In previous research, these devices already helped Janne to make important discoveries about the marathon flights that these birds make across the Sahara and their ability to keep up with climate warming. But there is more to discover…

We aimed at studying the role of wintering habitat quality for migration preparations and subsequent timing decisions, using these and other novel techniques and ecological research in Ivory Coast. For this, we took measures in 2018 on how the vegetation and insect food changes prior to departure from Africa. During our second expedition, we had great success in finding back and catching 14 of the 16 individuals that returned with their backpacks. Now it’s time to find out if differences in their wintering habitats have affected their timing of departure in Africa and arrival at their breeding sites.

Comoé National Park field station

Communicate story of tiny bird

We wanted you to join this journey, since we believe that the journey of this tiny bird can tell us an important story about the complexity of adaptation to global climate change. To communicate and inspire a broad audience about the amazing phenomenon of animal migration, Janne & Assia joined forces. Assia Kraan developed a mixed-media art project both in wintering grounds in Africa and back on the Dutch breeding grounds. In close collaboration Assia and Janne created the Flightcatcher Podcast; a 30 minute documentary with sounds from Africa, bird calls and interviews with researchers and locals. The results from this creative collaboration were showcased at the creative ‘city of talent’ Biotoop, during the annual Biotopendag in Haren (Netherlands) at 26 May 2019. With over 2000 visitors attending this day, the installation attracted many visitors, people were invited to listen to the podcast, and enjoy the photo presentation by Janne on ‘why and how’ this research is done. We aim to inspire people with the beauty of migration, make them aware of human impact on places and get them interested in conservation.

To be continued…

Although the fieldwork of the Flycatchers Project is over and the podcast & art work are presented, the scientific output is still in progress and Janne’s scientific journey continues. The National Geographic Explorers grant has helped enormously in establishing a novel non-breeding ecological research project on flycatchers in West-Africa. This provides a crucial step towards full annual-cycle research, to truly understand if migratory birds are able to maintain viable life-style in a rapidly changing world. Janne and her research team continue to share scientific insights, adventures and fascinations with you via this blog.


The Flycatchers Project is funded by a National Geographic Explorers grant and Prof. Both from the Conservation Ecology group of University of Groningen. Further support and equipment was provided by:,, Feldbrugge prototyping (equipement), Janna Bedaux (logo design)