When tracker Joy and I were recently tracking a female leopard on foot, we noticed the remains of a Leopard Tortoise’s shell in small pieces on the ground. After much deliberation as to what could have led to its demise, Joy suggested to me that the tortoise may have been caught and eaten by a Southern Ground Hornbill– which feeds on various prey species.
This got me thinking about the variety of beak sizes and shapes we see on the beautiful birds at Londolozi and how they help with their survival and reproduction.
The Woodland Kingfisher surprisingly does not feed on fish, it has a long, strong beak to capture insects, mainly locusts and grasshoppers.
What is a Beak?
The beak is made up of a finely strutted bone sheathed in a horny covering made of a tough protein called keratin. It is a highly adaptable and essential body part that plays a crucial role in each avian species. During the evolution of the bird, the heavy teeth and powerful jaw of their early reptilian ancestors were gradually changed into an efficient beak structure that is lighter and more robust, and is now found on the modern bird today.
The size and shape of the bird’s beak play a fundamental role in how the bird finds food or catches its prey.
A Green-backed Heron manipulates a dragonfly to make it easier to swallow whole.
Some birds, such as Herons and Egrets, have long, slender beaks that they use to spear fish and other aquatic creatures. Other birds, such as African Hawk-Eagles and Falcons, have sharp, hooked beaks that they use to catch and kill their prey mid-flight. Additionally, some birds, like the Yellow-billed Hornbill, use their beak to break open the top of active termite mounds to feed on the millions of termites, or sift through the leaf litter on the ground to find other invertebrates.
With the Sand River flowing strongly there has been an abundance of bird life and activity around the causeway and the middle channels. This Grey Heron seemed to have bitten off a bit more than it could chew. While wading through the shallows of the water it managed to stab a catfish. Once it had caught the catfish it proceeded to take it to dry land and stab it with its sharp beak to ensure it was not going to get away before swallowing it whole.
A Red-billed Hornbill sifts through a pile of elephant dung in search of many beetles and other insects that have moved in to feast on the dung, or little grubs and larvae that have recently hatched from their eggs within the dung.
Fundamental for Feeding
One of the most important functions of a bird’s beak is feeding. Birds have different types of beaks that are adapted to suit their diet. For example, a Cardinal Woodpecker has a long, sharp beak that it uses to drill into tree trunks to extract insects, while a Kingfisher has a large, sharp spear-like beak that it uses to ‘stab’ fish in the water.
After catching a small fish, a Pied Kingfisher attempts to swallow its prey head first to avoid a potentially life-threatening mishap. The sharp fins and scales of the fish lay flat when running from the head of the fish to the tail. If one was to swallow the fish tail first the fins and scales would flare out causing the fish to get stuck in the bird’s throat.
Similarly, a Sunbird has a long, thin beak that curves downwards to extract nectar from flowers, while a Common Greenshank has a long thin beak that curves upwards to probe in the mud around waterholes for any crustaceans or aquatics insects. Not to mention the Vulture, which has a sharp, hooked beak used to tear apart rotting flesh.
The long curved narrow beak in conjunction with a long tongue allows sunbirds to be masters of extracting nectar from flowers of aloes.
The Common Greenshank has a unique beak that is long, thin, and curves upwards to assist in probing for prey along the water’s edge.
Although the Hooded Vulture is at the bottom of the vulture hierarchy at a carcass, it has the ability to change the colour of its face in a show of excitement, dominance or aggression. Notice the large hook at the end of the beak which helps with tearing meat and cleaning meat out of the difficult-to-reach parts of a carcass.
Miraculous for Mate Attraction
In addition to helping birds find food, beaks also play a key role in attracting a mate. Many bird species have brightly coloured and uniquely shaped beaks that they use to attract the opposite sex during courtship. At Londolozi for example, the male Knob-billed Duck has an unusual fleshy comb on its upper mandible during the breeding season to attract a mate. Similarly, male fire finches have brightly coloured beaks that they use to showcase their fitness and attract a female.
Here you can see the prominent and enlarged knob on the bill of the male comb duck (Intra-African migrant) during the breeding season. It is not uncommon for birds to grow tail feathers in the breeding season but I’m not aware of too many birds growing appendages. Also visible in this photo are the iridescent (literally means ‘showing rainbow-like colours’) wing feathers which mostly appear dull greyish black.
A pair of Red-billed Firefinches drinking from a pool of water.
Crafty for Nest Building
A Groundscraper Thrush collects material for its nest. Clearly trying to fit as much as it could in its beak as possible.
Beaks also play an important role in nest-building. Many birds use their beaks to gather materials to build their nests, such as twigs, grass, and leaves. Additionally, some birds, like woodpeckers, use their beaks to drill holes into trees or other surfaces to create a cavity in which to build their nest.
A Cardinal Woodpecker feeds its chick through the hole nest it drilled out using its exceptionally strong beak
Diving deeper into understanding why birds have such different beaks reminds me how much I still have to learn about the bird world. It is fascinating how essential the beak is for a bird when eating, hunting, attracting a mate, as well as building a nest. Without their carefully adapted beaks, it would be difficult for birds to survive in the wild and fully optimise their niche that they occupy.
Nick Tennick
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