If you’ve ever noticed unusual noises, debris falling into your fireplace, or a sudden blockage in your chimney, jackdaws might be the culprits. These intelligent and social birds are common across the UK and Europe, and they have a particular fondness for chimneys when it comes to nesting. While they may seem harmless, their nesting behaviour can cause serious issues for homeowners, from fire hazards to ventilation problems.
Why Do Jackdaws Nest in Chimneys?
Jackdaws choose chimneys because they provide warmth, shelter, and protection from predators. A chimney is essentially a ready-made hollow space that mimics the tree cavities they would naturally use in the wild.
- Safety: Chimneys are hard for predators to access, making them a secure spot to raise chicks.
- Warmth: The brick structure provides insulation, keeping the nest at a stable temperature.
- Convenience: In urban and rural areas alike, chimneys are often more available than large hollow trees.
Unfortunately, once jackdaws start building, they bring in large amounts of twigs, straw, and other debris, which can block airflow and create significant risks inside your home.
How Long Do Jackdaws Nest in Chimneys?
Jackdaw nesting season usually runs from March to July, though this can vary slightly depending on the weather and location. They typically spend around 6 to 8 weeks actively using the nest once eggs are laid. Here’s what to expect:
- Nest building: Starts in early spring (March – April). This can take several days to weeks as jackdaws are persistent builders.
- Egg laying and incubation: The female lays 4 – 6 eggs, which hatch after about 18 – 20 days.
- Raising chicks: Chicks remain in the nest for about 4 – 5 weeks before fledging.
- After fledging: Even once the young leave, the nest structure often remains behind, clogging the chimney until it is professionally removed.
So, while jackdaws actively occupy the nest for only a couple of months, the impact on your chimney can last all year.
Conclusion
Jackdaws may only nest in chimneys for a short period, around 6 – 8 weeks, but the hazards they create can linger long after they’ve gone. If you suspect jackdaws are nesting in your chimney, it’s important to seek professional help. Pest control experts can safely remove old nests and advise on preventative measures, such as chimney cowls, to stop jackdaws from returning year after year.
