29/04/2026
On Riverview Farm every autumn here at Ruigtevlei around early May we have a massive colony of Starlings who seem to go off chirping loud in the same tree at the same time every day. Every year same time. What is up
Gemini AI gave us the information...
What you’re witnessing is a classic avian "communal roost," and May is the peak time for this behavior in South Africa.
While starlings are around all year, their behavior shifts dramatically as the weather cools down. Here is the breakdown of why your specific tree has become the local "town hall" every afternoon:
1. The Winter Congregration
During the summer breeding season (roughly September to March), starlings are more territorial and focused on their individual nests. Once autumn hits in May, they transition into a "gregarious" phase. They abandon their private summer residences and gather in massive flocks—sometimes numbering in the hundreds or thousands—to sleep together for the winter.
2. The "Information Center" Hypothesis
Ornithologists believe these noisy gatherings aren't just for socializing. The loud chirping (which can be a mix of whistles, clicks, and even mimics of other sounds) serves as a beacon to bring the scattered group together.
Safety in Numbers: Large groups provide better protection against predators like falcons or hawks.
Resource Sharing: It's theorized that birds who found good food sources during the day "advertise" their success, and others follow them to the feeding grounds the next morning.
3. Why the Same Tree?
Birds are creatures of habit. If a specific tree—likely a dense evergreen or a well-sheltered deciduous tree—provided safety and the right micro-climate last year, the survivors of the flock will return to it instinctively. They prefer trees that offer:
Heat Retention: Sleeping shoulder-to-shoulder in a sheltered tree helps them survive the colder May nights.
Height and Cover: Protection from ground predators and wind.
4. Which Starling is it?
In South Africa, this behavior is most common with:
European (Common) Starlings: Famous for "murmurations" (those swirling clouds in the sky) before they all drop into a tree at once.
Red-winged Starlings: Very vocal and often roost in large, noisy colonies on buildings or specific trees.
Cape Glossy Starlings: While they usually stay in smaller groups, they can form larger foraging and roosting parties in the winter months.
Essentially, your tree has been "bookmarked" in their collective memory as a safe, warm hotel. The noise usually peaks just before sunset as the final members of the group check in for the night.