The Black-tailed Godwit Chick Survival Project
Black-tailed Godwit
The black-tailed godwit – our national bird – has been under pressure for years. Despite numerous conservation measures, the number of breeding pairs continues to decline. Researchers now know where the problem lies: too few chicks survive their first few weeks of life. The Black-tailed Godwit Chick Survival Project (2026–2030) therefore focuses on one crucial question: why do so many black-tailed godwit chicks not make it, and what can we do about it?
Why chicks in particular?
Black-tailed godwits are so-called precocial birds: their chicks leave the nest shortly after hatching and immediately set out to find food themselves, under the guidance of their parents. During those first 20 to 40 days, they are extremely vulnerable. They need to grow quickly to become strong enough to fly and later migrate to Africa. But they face three major challenges:
- Food scarcity – fewer insects in the grassland
- Predation – birds of prey and mammals that eat chicks
- Land use – mowing, fertilisation and water management affect habitat and food
Exactly how these factors are interrelated is not yet fully understood. And it is precisely this insight that is needed to formulate effective policy.
Zuidwest-Friesland as a living laboratory
The research is taking place in an 11,500-hectare study area in Zuidwest-Friesland. Since 2004, precise records have been kept here of how many black-tailed godwits breed, how many nests are successful and how many chicks survive. Thanks to long-term collaboration with farmers, land managers and volunteers, this area has become one of the best-studied meadow bird areas in the world. These long-term data series make it possible to analyse trends reliably.
Three potential solutions
The project is investigating three possible ways to improve chick survival:
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More food for chicks
By measuring the abundance of insects in different types of grassland, the scientists are investigating which management practices – such as later mowing or higher water levels – are beneficial. -
Reduced predation
Using small camera traps, DNA analysis and transmitters, the project is identifying which predators are responsible for chick mortality, and how this relates to mouse population density and the landscape. -
‘Headstarting’ – an extra helping hand
This involves collecting eggs from areas without meadow bird management, hatching them artificially, and rearing the chicks safely until they are fledged. They are then released into the wild. This method is already used for highly endangered bird species, but its effectiveness for black-tailed godwits in the Netherlands is still unknown.
A unique experimental approach
What makes this project special is that it not only observes but also experiments.
Chicks in different landscapes
Some of the reared chicks are temporarily placed in small, fenced-off sections of plots with different management practices. During the day, they forage for food there under the supervision of the researchers. In the evening, they are brought safely indoors. This allows us to measure precisely how different land uses influence their growth when predation is not a factor.
Fast and slow growers
In a second experiment, some chicks are given a rich diet, comparable to the food supply in the 1980s, so they are expected to grow faster than chicks given a diet comparable to that of chicks growing up in the wild today. By dividing chicks from the same clutch into groups with different growth rates, researchers can investigate the long-term effects of a richer food supply. For example, is a fast-growing chick more likely to survive the migration?
In addition, wild and reared chicks will be fitted with ultra-light transmitters. These will allow researchers to track:
- Exactly where chicks forage
- How they move through the landscape
- When they depart for southern Europe or West Africa
- Which routes and habitats they use
- Whether and where they return to breed after 1–3 years
This technology makes it possible to track the entire journey from egg to adult breeding bird.
The large-scale computational model
All data – from insect numbers to migratory movements – is integrated into an advanced population model. This model simulates how the population develops under various scenarios.
For example, what happens if:
- The water level is kept structurally higher?
- Predation pressure decreases?
- Headstarting is applied annually?
This allows us to calculate in advance which combination of measures will result in the highest number of surviving young black-tailed godwits. This makes the model a powerful tool for policymakers.
What is at stake?
The question is not only whether individual chicks survive, but also whether Zuidwest-Friesland acts as a ‘source area’ (where more birds are produced than die off) or as a ‘sink’ (where the population survives only thanks to an influx from elsewhere).
The answer determines whether additional measures will have a local impact, or whether international cooperation is even more important. After all, black-tailed godwits overwinter in Spain, Portugal and West Africa – conservation does not stop at the national border.
More than just science
The project also has a strong social component. Farmers, nature organisations and government bodies are actively involved in developing scenarios. In workshops, research findings are translated into practical measures that are both ecologically and economically feasible.
The results are not only published in scientific journals, but also shared via public reports, lectures and online platforms where tagged black-tailed godwits can be tracked live, such as at https://www.globalflywaynetwork.org/.
Why this project is unique
- It combines twenty years of demographic data with new experiments.
- It investigates both direct causes (food, predation) and long-term effects (migration, settlement).
- It views the landscape from a chick’s perspective by tracking chick movements with ultra-light transmitters.
- It scientifically evaluates headstarting before it is potentially implemented on a large scale.
- It links fundamental ecology directly to policy choices.
Chicks as a compass
The project’s core message is clear: anyone who wants to understand how the agricultural landscape functions must look at the chicks. Their growth, behaviour and survival reflect the quality of the entire ecosystem.
If black-tailed godwit chicks can once again thrive in large numbers, this means:
- Sufficient insects
- A healthy soil biota
- Smart water management
- A balance between agriculture and nature
In other words: a thriving agricultural landscape.
The future of the black-tailed godwit therefore depends on small, well-hidden chicks in the grass. By closely monitoring their fate, researchers hope to point the way towards recovery – not just of one iconic bird species, but of the entire meadow landscape of which it is the symbol.
Contact persons
Georgette Lagendijk
Thomas Lameris
Simon Vandepitte
Roos Winters