Although the Cape robin-chat is not the only specie that uses a poo management system to safeguard their nests against predators, this was the first opportunity I had to record this strategy at its origin and most critical location… in the nest! This also serves to keep the nest dry and clean and reduces exposure to pathogens and parasites.
In essence the Cape robin-chat chicks put their poop in a strong mucus membrane that can be carried away by the parents without puncturing the bundle. Fecal sacs are just like disposable diapers for birds!
The parent encourages the chick to deliver its parcel directly after having fed the chick. The process is very quick… faster than you can say: "Kuhwrrrrap!" …the parent is gone… poo parcel and all!Large viewLarge viewLarge viewLarge view
For the first couple of days after hatching, parent may actually eat many of the chicks' fecal sacs. Initially the chicks' intestines don't have much bacteria to help them digest their food. Before the bacteria kick in, the droppings are full of partially-digested food items so that the parents can take advantage of the food still in the droppings. Eating the poo parcels permits the parents to give more of the prey they find to their babies rather than eating this food themselves.
Making fecal sacs takes protein. But it's worth the cost when nest sanitation is at risk, but as soon as the chicks leave the nest, they stop producing fecal sacs and make a poop just like an adult bird… one that splats instead of bouncing.
I knew something was taking place when I noticed the robin-chats busily fluttering about in the same corner of the garden. For years I have been trying to locate their nest. This time, determined to succeed, I sat down in a comfortable chair close by to watch them go about their business. It still took three hours to discover the location of the nest.
She is raising two chicks in a cup-shaped nest that she and her partner for life built together in the embrace of a creeper that covers a gazebo in our garden. She did most of the construction work, building with course plant material and thickly lining the nest with soft materials like animal hair, lichen and fine rootlets. It is cleverly camouflaged in the complex joint of a climber that covers the gazebo, about 1.3m off the ground. The female performed all the incubation and brooding duties. The male's participation in caring for the young is limited to feeding, initially he provides very little of the food, but this contribution is said to steadily increase as the demand from the chicks grows. So far I have not seen that happen, though. Zorro (so named by a friend and the name stuck
) hangs about on guard duty, continuously supporting the female bird with soft, guttural three and four syllable “all-is-clear, go-go-my dear” encouragements.
And what a hunter she is! There in the nest she is every 20 minutes or so with a load of food. And the variety is stunning. She forages for food on the ground, whisking leaves and litter, on lawns and in trees, sometimes hawking prey aerially. Cossypha caffra mainly eats insects, but sometimes ripe fruit is used. Its prey includes ants, butterflies, bees, beetles, caterpillars, millipedes, termites, spiders, crickets, mantids, moths, wasps, locusts, grasshoppers, katydids and a variety of flies.
Some samples of her catches are reflected below.
Milipede and caterpillar
Mixed grill Katydid, moth
Hover fly (a harmless bee mimic)
As I collected photographs of this female, I was able to decipher the number on her ring. It turns out to be CV43517, a ring put on her by my ringer friend Colin Williams in October last year. Zorro also wears a ring, but we have not been able to read the number yet.
The Cape Robin-chat, is probably South Africa’s best known and best loved garden bird. They lay 2 to 4 eggs. The robin-chat is the favourite breeding host of the Red-chested cuckoo (Piet-my-vrou). The Piet-my-vrou does not remove the robin eggs, but cuckoos hatch about 3 or 4 days sooner than their hosts. Then the young cuckoo chick, specially equipped for the job, tip the robin chicks out when they hatch. This often happens while the female robin is busy brooding. They say that the baby robin is pushed out on the hollow back of the young cuckoo, over the side. In spite of the female robin being present, she seems to take no notice of the whole procedure.
The cuckoo chick, once it is alone in the nest with no competition for food, grows very fast. At 10 days it is often about twice the size of the adult robin. When the robin comes to feed the chick, it seems as if the youngster grabs the food, robin and all, it’s gape is so big. At this stage the robin often sits on the back of the imposter chick while feeding it!
C. caffra breeds for most of the year, but summer is the peak breeding season. Now is the best time to try and find that breeding pair’s nest. Approximately 1/8 of Zorro’s chicks can turn out to be a Piet-my-vrou step child. To find something like that in a robin-chat nest is a Jackpot happening. I have high hopes of finding this phenomenon some day.
Cape robin-chats feature in virually every garden in our big cities! It is the first bird to start singing in the morning! They are skulkers, though... spending much time in thickets. If you have a bird bath, that is where you will see them quite easily as they love to take a dip!