EcoTraining Instructor Ross Hawkins spends most of his time instructing on Trails Guide or Wilderness Trails Courses, so being on foot most of his day he does tend to see things on the ground level a bit more than those who are in the game drive vehicle. Small things such as birds nests and eggs sometimes get lost do to their camouflage, and there is a reason behind that.
Why not start with this EcoTraining Crossword and test your knowledge:
The white-backed night heron is an elusive and rather poorly known species of crepuscular piscivore. A relative of the much more common black-crowned night heron, this secretive and shy inhabitant of slow-flowing rivers and dams are generally regarded as rare throughout a rather wide distribution. They can be seen from the east cape of South Africa along the Indian coastal belt through to the Lowveld and into parts of Southern and central Africa.
But they can only be spotted in their suitable habitat which makes finding them for your life list that much trickier.
The species stronghold is undoubtedly the Okavango Delta where local mokoro based excursions from many lodges in the area offer a good chance of connecting with this sought after skulker. Birds are most often seen when flushed from bank waterside vegetation where they roost in the deepest shade during the daylight hours. They are generally active from early evening into the night before flying back to their roost sites as dawn approaches.
Their hunting methods
White-backed Night Herons (Gorsachius leuconotus) as with most herons are opportunistic feeders with fish, arthropods, frogs and freshwater crabs comprising most of its diet. Some of their prey will simply be seized because it is available. A strong spear-shaped bill is used to spear passing prey at such speeds that the prey passing won’t know what hit them.
Underwater prey is waited for patiently, usually from vegetation overhanging the surface of the water or from a waded position just out from the bank. These birds can sit motionless for long periods of time until the opportunity arises. Like all herons, they possess specialised neck vertebrae. The neck is able to kink in an S-shape, due to the modified shape of the cervical vertebrae. This acts as a coil spring which gives their hefty bill incredible speed when the head is shot forward towards unsuspecting prey.
Another incredible feature of this hunting method is that these birds automatically take into account the refraction that takes place when looking into the water. The head of a heron corrects for light refraction at the water’s surface by adjusting the position and keeping a constant relationship between real and apparent prey depth.
Where do they occur in South Africa?
In South Africa, there are very few reliable places to find this endearing species with several sites along the garden route and Eastern Cape, Lake Phobane in Kwa-Zulu Natal and Lake Albasini in Limpopo offering some of the better chances. Something that is quite exciting is that this special species has been recorded quite regularly at EcoTraining Karongwe Camp. Most records are from the weir along the Karongwe River within the reserve, but birds have been seen at nearby Spectre and GVI Dams as well as from within camp itself.
This is wonderful news for birders who have been eluded by this beautiful bird as here at Karongwe there is the potential, for those who are fortunate, to access one of Africa’s most desired birds while taking in the beauty of the African wilderness and the stunning Lowveld.
If you are a keen birder or want to learn more about birds, why don’t you try your hand at our EcoTraining Bird Challenge?
They may have a bad rap in literature (One Flew Over the Cuckoo’s Nest and The Midwich Cuckoos for example) but there are few more fascinating birds than cuckoos. In Southern Africa, cuckoos are all migrants, except for the Klaas’s Cuckoo which is a resident in some lowland areas. This means that they are absent from the region for most of the year, only moving down from further north in Africa and Asia during the rainy season.
While cuckoos tend to migrate from as early as September, typically most arrive in late October to November. Most of the 15 species we have in South Africa are intra-African migrants, which means that they come down from countries further north within Africa, down to the south of the continent. There are also a few Palearctic migrants, namely the Common (European) Cuckoo and the Lesser Cuckoo, with the Common Cuckoo coming from China, Korea and Japan and the Lesser Cuckoo coming from Afghanistan and the foothills of the Himalayas. These Palearctic migrants are, however, much less common than the intra-African migrants.
One of the reasons cuckoos migrate down to our neck of the woods is to feast upon the vast insect numbers that come to life after the early summer rains have fallen – specifically to eat the processionary worms (hairy caterpillars) that you will often see huddled together on tree branches, particularly on the Velvet Corkwood tree (Commiphora mollis). In fact, cuckoos are specialised in eating the hairy caterpillars, which are – for good reason – avoided by most other birds. For their meals, cuckoos smash the caterpillars against branches and other objects to remove the caterpillar’s irritating hairs. These caterpillars are the larval stage of the reticulate bagnest moth (Anaphe reticulata).
In spite of their dark reputation (see the books mentioned above and the saying “you’ve gone cuckoo”!), cuckoos are renowned for having very musical songs. That said, not all species are known for holding a tune with the Clamator cuckoos (Levaillant’s, Jacobin and great spotted cuckoo’s) have more of a chattering, unmusical call. But a few have such characteristic songs that it has resulted in their actual common name. For example, the red-chested cuckoo is called the Piet-my-vrou in Afrikaans, which is an onomatopoeic rendition of the distinct “quid-pro-quo” sounding call it monotonously sings. The Diederick cuckoo is called a Diederikkie in Afrikaans which is also a reference to its call which sounds like “dee-dee-deederick”.
Most cuckoos that migrate to Southern Africa breed during their stay here. Their breeding behaviour is very interesting and unlike that of most other birds. All of the locally occurring cuckoos are what we call “brood parasites”. A “brood parasite” is a bird that lays its eggs or egg in another bird’s nest, in the hopes that their clutch will outcompete the host’s eggs and the host bird will incubate and raise the cuckoo’s chicks. This is done for a few reasons: the cuckoo expends less energy as it does not need to raise its own chick and by laying eggs in a few different nests, the risk is spread and therefore the chances of the chicks being successfully raised is increased. To achieve this parasitism, cuckoos have developed techniques to trick their host birds: most cuckoos have developed what is called “egg-mimicry” in which their eggs look similar in size, colour and shape to that of the host’s egg. Typically, the cuckoo will also evict an egg from the host nest, for each one she lays. When they hatch, some cuckoos – like the African emerald cuckoo and the Diederick – will even evict unhatched host eggs. After hatching (and while still blind) the hatchling will back up to the host’s egg, collect it in a special cavity and then toss it over the edge of the nest. They may do this to the host’s young chicks as well. Alternatively, the cuckoo chick will hack and peck the host chicks to death once they have hatched – and which might just help explain their reputation in popular culture! However, in some cases, the parasite and host chicks are raised together without any hostility.
Another interesting point to add is that males often perform “courtship-feeding”, in which they feed caterpillars to females in an attempt to court them. This often leads people to believe that the cuckoo is feeding one of its own, yet this is not true as no local cuckoo species raises its young.
Cuckoos are amazing birds and are fascinating even to non-twitchers, particularly for their long-distance travel, nesting behaviour and beautiful melodic calls. Unfortunately, however, catching sight of a cuckoo is not easy as they are only seen – and more often just heard – in the rainy season.
This, however, just makes their presence more special as they are here to tell us that summer has well and truly begun!
Are you keen on birds or learning more about them, have a look at our Birding in the Bush course we offer.
Still want to learn something more today, have a look at the bird quizzes we have available: