Fork-tailed Drongos are fairly ubiquitous across Londolozi and the region in general.
They are often found following large herbivores through the bush, hoping to capitalise on any insect prey flushed out from disturbed grass and branches as the herbivores move through.
But – as with many of the smaller bird species we see here – it’s not often we see their nests. Recently however, we came across one in plain sight:
The problem that this drongo pair is going to face is the exposure of the nest. I don’t know what the exact environmental cues are that induce nest building, mating and laying, but it seems to me that this pair was a week or two early. The red bushwillow tree the nest is in is just starting to bud, and another 10 days or so would have seen the nest being well hidden. Or at least if not hidden, partially disguised.
Instead it is very visible (we spotted it from the road with no difficulty) which makes the nest very vulnerable to predators.
Another danger for the drongos is the African Cuckoo, a brood parasite . The various cuckoo species are just starting to arrive at Londolozi (we heard our first red-chested about a week ago and the Klaas’s have been calling for a while now) and their breeeding strategy involves laying their eggs in the nest of another bird species, allowing that host species to raise their chick(s) for them.
Some cuckoos are generalist, laying their eggs in a wide range of host nests, whilst some – of which the African Cuckoo is one – are specialist, only parsitising one species.
The Fork-Tailed Drongo is the host of the African Cuckoo, and a nest like the one featured here is a prime target.
The adult cuckoos search for a drongo nest together. Once one is discovered, the male cuckoo distracts the drongos while the female cuckoo sneaks in to lay an egg, removing one of the drongo eggs in the process. The drongo returns to find the correct number of eggs in the nest, and is none the wiser. Cuckoos have even evolved to have their eggs mimic that of the host, so the drongo doesn’t realise the switch has been made.
When the cuckoo chick hatches, it pushes the drongo eggs out of the nest and is raised on its own by the drongo adults.
I have yet to hear an African Cuckoo this season, but they’re on their way, and may even be here already for all I know. It may be that this drongo pair just snuck in their clutch on time to avoid the cuckoo danger, thereby balancing the disadvantage of an exposed nest against the advantage of an early pre-cuckoo clutch. Personally I doubt that was an active decision they made or that kind of thinking takes place in a drongo’s mind, but even if the worst happens, drongos are well know for their ability to be able to replace a clutch if the first one fails.
We will watch this nest with interest, and as much as I don’t want to see it happen for the sake of the drongos themselves, it will be fascinating to watch the outcome should a cuckoo pair find the nest and parasitise it…