Cuckoo Confusion – Londolozi Blog

Still very much nestled in the heart of winter, there are many pros to this time of year. I would go so far as to argue that it is my favourite time of year. One of the downsides, however, is that most of the migratory birds are still well north of us, in either Northern Africa or some as far as Europe and the Middle East. While this is a blog post in itself, the incredible feat that is migration – on a recent game drive we spotted a Klaas’s Cuckoo, a bird usually found this time of year in North Africa (from Senegal in the west to Ethiopia in the east).

To understand this, we need to start at the beginning: with the exception of the Common Cuckoo, all the other cuckoos at Londolozi will breed here during the summer months. Compared to most other birds, the breeding strategy of cuckoos is unconventional, to say the least.

Cuckoos play absolutely no role in raising their young; what they do instead, is get other birds to incubate and raise their chicks for them, a behaviour known as brood parasitism. A Klass’s Cuckoo, for example, will attempt to lay its eggs in the nest of any unsuspecting species of Sunbirds or a Chin Spot Batis nest. The batis will then try to chase the cuckoo away but all the cuckoo needs is a few seconds to lay its egg amongst the eggs of the batis.

A Marsh Warbler nest containing a slightly larger Common Cuckoo egg in the top left and four warbler eggs.

On a quick side note – as if the breeding habits of cuckoos weren’t bizarre enough, things become even more unbelievable when the young cuckoos leave the nest. The cuckoos almost instinctively know how to act like cuckoos despite the fact that they are raised by birds of a completely different species. Case in point: the Klaas’s cuckoo will most often be raised together with the chicks of the batis and will learn the call that the batis chicks use when begging for food. The same Klaas’s Cuckoo will forget the call of the begging batis chicks and be able to give off a pitch-perfect Klaas’s Cuckoo call without ever being taught.

Klaas’s Cuckoos naturally are able to give off a perfect call and know exactly where and when to migrate.

Further still, all these freshly born cuckoos that belong to species that migrate during our winter months know exactly what time of year to leave Londolozi and which specific route to take without any guidance from other cuckoos. It is unfathomable how they know what to do, yet nature has a way of amazing us in so many different ways.

Here a Burchell’s Starling feeds a Great Spotted Cuckoo.

Now, understanding the complexities of a young cuckoo chick’s first year – it is not unreasonable to assume that some birds will miss the first migration that all others of the same species take part in. Of the eleven different species of cuckoo encountered at Londolozi, all are considered migratory (although one or two individuals do over-winter on occasion). However, if there is a cuckoo spotted here during the winter months, chances are (9 times out of 10) that it will be a Klaas’s Cuckoo.

While we still aren’t 100% certain as to why this specific species of cuckoo tends to over-winter more than others, there a records of resident breeding pairs recorded in all low-lying areas of their range (into which we fall). Perhaps the general trend in weather patterns is allowing the birds to survive a traditionally tougher winter, and with less competition from other cuckoos over food, the Klaas’s Cuckoo has started to break the mould of migration?

Whatever the reason, the distinctive call of the Klaas’ Cuckoo is already being heard, and it won’t be long before the rest follow. When winter eventually gives way to spring, the green leaves will arrive and with it the caterpillars and the cuckoos. But rest assured the cuckoos will leave like they always do, and the curious case of the cuckoos will again be reopened again.